Cutis

Practice Gap

Habit-tic nail deformity results from repetitive manipulation of the cuticle and/or proximal nail fold. It most commonly affects one or both thumbnails and presents with a characteristic longitudinal midline furrow with parallel transverse ridges in the nail plate. Complications may include permanent onychodystrophy, frictional melanonychia, and infections. Treatment is challenging, as diagnosis first requires patient insight to the cause of symptoms. Therapeutic options include nonpharmacologic techniques (eg, occlusion of the nails to prevent trauma, cyanoacrylate adhesives, cognitive behavioral therapy) and pharmacologic techniques (eg, N-acetyl cysteine, selective serotonin reuptake inhibitors, tricyclic antidepressants, antipsychotics), with limited supporting data and potential adverse effects.¹

The Technique

Benzethonium chloride solution 0.2% is an antiseptic that creates a polymeric layer that binds to the skin. It normally is used to treat small skin erosions and prevent blisters. In patients with habit-tic nail deformity, we recommend once-daily application of benzethonium chloride to the proximal nail fold, thereby artificially recreating the cuticle and forming a sustainable barrier from trauma (Figure, A). Patients should be reminded not to manipulate the cuticle and/or nail fold during treatment. In one 36-year-old man with habit tic nail deformity, we saw clear nail growth after 4 months of treatment (Figure, B).

Practice Implications

Successful treatment of habit-tic nail deformity requires patients to have some insight into their behavior. The benzethonium chloride serves as a reminder for patients to stop picking as an unfamiliar artificial barrier and reminds them to substitute the picking behavior for another more positive behavior. Therefore, benzethonium chloride may be offered to patients as a novel therapy to both protect the cuticle and alter behavior in patients with habit-tic nail deformity, as it can be difficult to treat with few available therapies.

Allergic contact dermatitis to benzethonium chloride is a potential side effect and patients should be cautioned prior to treatment; however, it is extremely rare with 6 cases reported to date based on a PubMed search of articles indexed for MEDLINE using the terms allergic contact dermatitis and benzethonium chloride,² and much rarer than contact allergy to cyanoacrylates.

Practice Gap

Habit-tic nail deformity results from repetitive manipulation of the cuticle and/or proximal nail fold. It most commonly affects one or both thumbnails and presents with a characteristic longitudinal midline furrow with parallel transverse ridges in the nail plate. Complications may include permanent onychodystrophy, frictional melanonychia, and infections. Treatment is challenging, as diagnosis first requires patient insight to the cause of symptoms. Therapeutic options include nonpharmacologic techniques (eg, occlusion of the nails to prevent trauma, cyanoacrylate adhesives, cognitive behavioral therapy) and pharmacologic techniques (eg, N-acetyl cysteine, selective serotonin reuptake inhibitors, tricyclic antidepressants, antipsychotics), with limited supporting data and potential adverse effects.¹

The Technique

Benzethonium chloride solution 0.2% is an antiseptic that creates a polymeric layer that binds to the skin. It normally is used to treat small skin erosions and prevent blisters. In patients with habit-tic nail deformity, we recommend once-daily application of benzethonium chloride to the proximal nail fold, thereby artificially recreating the cuticle and forming a sustainable barrier from trauma (Figure, A). Patients should be reminded not to manipulate the cuticle and/or nail fold during treatment. In one 36-year-old man with habit tic nail deformity, we saw clear nail growth after 4 months of treatment (Figure, B).

Practice Implications

Successful treatment of habit-tic nail deformity requires patients to have some insight into their behavior. The benzethonium chloride serves as a reminder for patients to stop picking as an unfamiliar artificial barrier and reminds them to substitute the picking behavior for another more positive behavior. Therefore, benzethonium chloride may be offered to patients as a novel therapy to both protect the cuticle and alter behavior in patients with habit-tic nail deformity, as it can be difficult to treat with few available therapies.

Allergic contact dermatitis to benzethonium chloride is a potential side effect and patients should be cautioned prior to treatment; however, it is extremely rare with 6 cases reported to date based on a PubMed search of articles indexed for MEDLINE using the terms allergic contact dermatitis and benzethonium chloride,² and much rarer than contact allergy to cyanoacrylates.

Practice Gap

Habit-tic nail deformity results from repetitive manipulation of the cuticle and/or proximal nail fold. It most commonly affects one or both thumbnails and presents with a characteristic longitudinal midline furrow with parallel transverse ridges in the nail plate. Complications may include permanent onychodystrophy, frictional melanonychia, and infections. Treatment is challenging, as diagnosis first requires patient insight to the cause of symptoms. Therapeutic options include nonpharmacologic techniques (eg, occlusion of the nails to prevent trauma, cyanoacrylate adhesives, cognitive behavioral therapy) and pharmacologic techniques (eg, N-acetyl cysteine, selective serotonin reuptake inhibitors, tricyclic antidepressants, antipsychotics), with limited supporting data and potential adverse effects.¹

The Technique

Benzethonium chloride solution 0.2% is an antiseptic that creates a polymeric layer that binds to the skin. It normally is used to treat small skin erosions and prevent blisters. In patients with habit-tic nail deformity, we recommend once-daily application of benzethonium chloride to the proximal nail fold, thereby artificially recreating the cuticle and forming a sustainable barrier from trauma (Figure, A). Patients should be reminded not to manipulate the cuticle and/or nail fold during treatment. In one 36-year-old man with habit tic nail deformity, we saw clear nail growth after 4 months of treatment (Figure, B).

Practice Implications

Successful treatment of habit-tic nail deformity requires patients to have some insight into their behavior. The benzethonium chloride serves as a reminder for patients to stop picking as an unfamiliar artificial barrier and reminds them to substitute the picking behavior for another more positive behavior. Therefore, benzethonium chloride may be offered to patients as a novel therapy to both protect the cuticle and alter behavior in patients with habit-tic nail deformity, as it can be difficult to treat with few available therapies.

Allergic contact dermatitis to benzethonium chloride is a potential side effect and patients should be cautioned prior to treatment; however, it is extremely rare with 6 cases reported to date based on a PubMed search of articles indexed for MEDLINE using the terms allergic contact dermatitis and benzethonium chloride,² and much rarer than contact allergy to cyanoacrylates.

Case Report

A 32-year-old woman presented to the dermatology clinic with a tender lump overlying the right maxilla of 6 weeks’ duration. The lesion developed acutely 1 to 2 months after the patient began using an at-home microdermabrasion device, which she routinely cleaned with tap water. The physical examination was notable for a 1.5-cm, soft, superficially indurated plaque on the right cheek without associated lymphadenopathy (Figure).

A punch biopsy revealed underlying necrotic fat. Computed tomography of the neck showed 20-mm skin thickening overlying the right zygomatic arch, with minimal adjacent subcutaneous soft tissue stranding and reactive lymph nodes. Further histologic examination of the biopsy specimen revealed inflamed granulation tissue with granulomatous inflammation.

Acid-fast bacterial culture was positive. Subsequent speciation revealed the causal agent to be multidrug-resistant Mycobacterium abscessus. The patient was initially treated with trimethoprim-sulfamethoxazole, which was switched to a combination of doxycycline and levofloxacin a few days later after initial culture returned. The following week, after the specific microorganism was confirmed with specific sensitivity, treatment was changed to intravenous (IV) tigecycline and amikacin. This regimen was continued for 2 more months through a peripherally inserted central catheter, then discontinued after complete resolution of the skin lesion.

Comment

Mycobacterial Infection
Nontuberculous mycobacteria were not identified as human pathogens until the 1950s. They are known to cause skin disease, lymphadenitis, skeletal infection, pulmonary disease, and disseminated infection, with pulmonary disease being the most common clinical form overall.¹Mycobacterium abscessus is a member of a more specific group known as rapidly growing nontuberculous mycobacteria, which also includes Mycobacterium fortuitum and Mycobacterium chelonae.² Commonly found in water, soil, and dust, M abscessus causes skin and soft tissue infection after skin injury by inoculation, minor trauma, or surgery.^2-4 An increased rate of infections recently has been attributed to an increase in cosmetic procedures such as tattooing, liposuction, mesotherapy, pedicures, and body piercing. Mycobacterial infections transmitted through acupuncture also have been documented.^5,6

Causes of Skin and Soft Tissue Infections
Skin and soft tissue infections due to rapidly growing mycobacteria often are associated with systemic comorbidities that cause immunosuppression and with immunosuppressive medications.⁷ Our patient did not have a preexisting comorbidity and did not take any long-term medication. When multiple lesions have been reported, patients were more likely to either have a systemic comorbidity or be taking immunosuppressive medication compared to patients with a single lesion. A history of penetrating trauma or an invasive surgical procedure has been reported more often in patients with a single lesion.⁷

Our patient had a solitary lesion on the face; improper sterile technique while using an at-home microdermabrasion device was thought to be the cause of infection. Although generally considered a minimally abrasive treatment modality, microdermabrasion caused enough trauma to create a nidus of infection in our patient.

Presentation
Cutaneous infection from rapidly growing mycobacteria can manifest as a nonhealing ulceration, subcutaneous abscess, draining sinus, or subcutaneous fluctuant or firm nodules. Erythema may be found in association with ulcers or chronic drainage from a surgical wound.^2,7

Histopathologic appearance varies, depending on the evolution of the disease and host immunologic status. Tuberculoid, palisading, and sarcoidlike granulomas; a diffuse infiltrate of histiocytic foamy cells; acute and chronic panniculitis; nonspecific chronic inflammation; cutaneous abscess; suppurative granuloma; and necrotizing folliculitis all can be seen.⁸ Immunosuppressed patients are less likely to form granulomas.⁶ Diagnosis often is delayed because acid-fast bacterial culture is not typically performed on skin biopsy specimens or surgical wound infections.⁷ Fortunately, a high index of suspicion in our patient’s case allowed for prompt diagnosis and expeditious management.

Management
Mycobacterium abscessus tends to be resistant to conventional antituberculous medications; overall, it is considered a highly drug-resistant pathogen that is difficult to treat.^9,10 Treatment usually requires 3 to 6 months of therapy, with oral clarithromycin considered the first-line agent for localized infection.⁵ Because cases of clarithromycin resistance have been reported in patients with M chelonae infection, caution is warranted when deciding between monotherapy or combination therapy.⁷ Multidrug resistance often necessitates prolonged IV therapy. Amikacin is the mostly commonly used IV agent for M abscessus infection. Adverse effects of treatment are common, often leading to a change in or discontinuation of therapy.¹¹

Our patient was initially given trimethoprim-sulfamethoxazole before being switched to doxycycline and levofloxacin prior to final results of susceptibility testing. Ultimately, due to the multidrug-resistant nature of M abscessus, clarithromycin was not a viable option. Therefore, the patient was administered tigecycline and amikacin through a peripherally inserted central catheter until symptoms fully resolved.

Surgery can be an important adjunctive measure for certain patients, especially those with a single lesion.⁷ Our patient did well with medical treatment alone.

Conclusion

Given the difficulty of treating skin and soft tissue infections caused by M abscessus and related mycobacteria, it is worth noting that these infections are increasingly caused by procedures generally considered to be minimally invasive. Microdermabrasion—performed at home in an unsterile environment and not by a trained medical professional—was the causal procedure in this case. An important consideration is whether clinicians can be comfortable with the use of these treatments at home or whether they should be advising patients against at-home treatments that have potentially serious complications.

Case Report

A 32-year-old woman presented to the dermatology clinic with a tender lump overlying the right maxilla of 6 weeks’ duration. The lesion developed acutely 1 to 2 months after the patient began using an at-home microdermabrasion device, which she routinely cleaned with tap water. The physical examination was notable for a 1.5-cm, soft, superficially indurated plaque on the right cheek without associated lymphadenopathy (Figure).

A punch biopsy revealed underlying necrotic fat. Computed tomography of the neck showed 20-mm skin thickening overlying the right zygomatic arch, with minimal adjacent subcutaneous soft tissue stranding and reactive lymph nodes. Further histologic examination of the biopsy specimen revealed inflamed granulation tissue with granulomatous inflammation.

Acid-fast bacterial culture was positive. Subsequent speciation revealed the causal agent to be multidrug-resistant Mycobacterium abscessus. The patient was initially treated with trimethoprim-sulfamethoxazole, which was switched to a combination of doxycycline and levofloxacin a few days later after initial culture returned. The following week, after the specific microorganism was confirmed with specific sensitivity, treatment was changed to intravenous (IV) tigecycline and amikacin. This regimen was continued for 2 more months through a peripherally inserted central catheter, then discontinued after complete resolution of the skin lesion.

Comment

Mycobacterial Infection
Nontuberculous mycobacteria were not identified as human pathogens until the 1950s. They are known to cause skin disease, lymphadenitis, skeletal infection, pulmonary disease, and disseminated infection, with pulmonary disease being the most common clinical form overall.¹Mycobacterium abscessus is a member of a more specific group known as rapidly growing nontuberculous mycobacteria, which also includes Mycobacterium fortuitum and Mycobacterium chelonae.² Commonly found in water, soil, and dust, M abscessus causes skin and soft tissue infection after skin injury by inoculation, minor trauma, or surgery.^2-4 An increased rate of infections recently has been attributed to an increase in cosmetic procedures such as tattooing, liposuction, mesotherapy, pedicures, and body piercing. Mycobacterial infections transmitted through acupuncture also have been documented.^5,6

Causes of Skin and Soft Tissue Infections
Skin and soft tissue infections due to rapidly growing mycobacteria often are associated with systemic comorbidities that cause immunosuppression and with immunosuppressive medications.⁷ Our patient did not have a preexisting comorbidity and did not take any long-term medication. When multiple lesions have been reported, patients were more likely to either have a systemic comorbidity or be taking immunosuppressive medication compared to patients with a single lesion. A history of penetrating trauma or an invasive surgical procedure has been reported more often in patients with a single lesion.⁷

Our patient had a solitary lesion on the face; improper sterile technique while using an at-home microdermabrasion device was thought to be the cause of infection. Although generally considered a minimally abrasive treatment modality, microdermabrasion caused enough trauma to create a nidus of infection in our patient.

Presentation
Cutaneous infection from rapidly growing mycobacteria can manifest as a nonhealing ulceration, subcutaneous abscess, draining sinus, or subcutaneous fluctuant or firm nodules. Erythema may be found in association with ulcers or chronic drainage from a surgical wound.^2,7

Histopathologic appearance varies, depending on the evolution of the disease and host immunologic status. Tuberculoid, palisading, and sarcoidlike granulomas; a diffuse infiltrate of histiocytic foamy cells; acute and chronic panniculitis; nonspecific chronic inflammation; cutaneous abscess; suppurative granuloma; and necrotizing folliculitis all can be seen.⁸ Immunosuppressed patients are less likely to form granulomas.⁶ Diagnosis often is delayed because acid-fast bacterial culture is not typically performed on skin biopsy specimens or surgical wound infections.⁷ Fortunately, a high index of suspicion in our patient’s case allowed for prompt diagnosis and expeditious management.

Management
Mycobacterium abscessus tends to be resistant to conventional antituberculous medications; overall, it is considered a highly drug-resistant pathogen that is difficult to treat.^9,10 Treatment usually requires 3 to 6 months of therapy, with oral clarithromycin considered the first-line agent for localized infection.⁵ Because cases of clarithromycin resistance have been reported in patients with M chelonae infection, caution is warranted when deciding between monotherapy or combination therapy.⁷ Multidrug resistance often necessitates prolonged IV therapy. Amikacin is the mostly commonly used IV agent for M abscessus infection. Adverse effects of treatment are common, often leading to a change in or discontinuation of therapy.¹¹

Our patient was initially given trimethoprim-sulfamethoxazole before being switched to doxycycline and levofloxacin prior to final results of susceptibility testing. Ultimately, due to the multidrug-resistant nature of M abscessus, clarithromycin was not a viable option. Therefore, the patient was administered tigecycline and amikacin through a peripherally inserted central catheter until symptoms fully resolved.

Surgery can be an important adjunctive measure for certain patients, especially those with a single lesion.⁷ Our patient did well with medical treatment alone.

Conclusion

Given the difficulty of treating skin and soft tissue infections caused by M abscessus and related mycobacteria, it is worth noting that these infections are increasingly caused by procedures generally considered to be minimally invasive. Microdermabrasion—performed at home in an unsterile environment and not by a trained medical professional—was the causal procedure in this case. An important consideration is whether clinicians can be comfortable with the use of these treatments at home or whether they should be advising patients against at-home treatments that have potentially serious complications.

Case Report

A 32-year-old woman presented to the dermatology clinic with a tender lump overlying the right maxilla of 6 weeks’ duration. The lesion developed acutely 1 to 2 months after the patient began using an at-home microdermabrasion device, which she routinely cleaned with tap water. The physical examination was notable for a 1.5-cm, soft, superficially indurated plaque on the right cheek without associated lymphadenopathy (Figure).

A punch biopsy revealed underlying necrotic fat. Computed tomography of the neck showed 20-mm skin thickening overlying the right zygomatic arch, with minimal adjacent subcutaneous soft tissue stranding and reactive lymph nodes. Further histologic examination of the biopsy specimen revealed inflamed granulation tissue with granulomatous inflammation.

Acid-fast bacterial culture was positive. Subsequent speciation revealed the causal agent to be multidrug-resistant Mycobacterium abscessus. The patient was initially treated with trimethoprim-sulfamethoxazole, which was switched to a combination of doxycycline and levofloxacin a few days later after initial culture returned. The following week, after the specific microorganism was confirmed with specific sensitivity, treatment was changed to intravenous (IV) tigecycline and amikacin. This regimen was continued for 2 more months through a peripherally inserted central catheter, then discontinued after complete resolution of the skin lesion.

Comment

Mycobacterial Infection
Nontuberculous mycobacteria were not identified as human pathogens until the 1950s. They are known to cause skin disease, lymphadenitis, skeletal infection, pulmonary disease, and disseminated infection, with pulmonary disease being the most common clinical form overall.¹Mycobacterium abscessus is a member of a more specific group known as rapidly growing nontuberculous mycobacteria, which also includes Mycobacterium fortuitum and Mycobacterium chelonae.² Commonly found in water, soil, and dust, M abscessus causes skin and soft tissue infection after skin injury by inoculation, minor trauma, or surgery.^2-4 An increased rate of infections recently has been attributed to an increase in cosmetic procedures such as tattooing, liposuction, mesotherapy, pedicures, and body piercing. Mycobacterial infections transmitted through acupuncture also have been documented.^5,6

Causes of Skin and Soft Tissue Infections
Skin and soft tissue infections due to rapidly growing mycobacteria often are associated with systemic comorbidities that cause immunosuppression and with immunosuppressive medications.⁷ Our patient did not have a preexisting comorbidity and did not take any long-term medication. When multiple lesions have been reported, patients were more likely to either have a systemic comorbidity or be taking immunosuppressive medication compared to patients with a single lesion. A history of penetrating trauma or an invasive surgical procedure has been reported more often in patients with a single lesion.⁷

Our patient had a solitary lesion on the face; improper sterile technique while using an at-home microdermabrasion device was thought to be the cause of infection. Although generally considered a minimally abrasive treatment modality, microdermabrasion caused enough trauma to create a nidus of infection in our patient.

Presentation
Cutaneous infection from rapidly growing mycobacteria can manifest as a nonhealing ulceration, subcutaneous abscess, draining sinus, or subcutaneous fluctuant or firm nodules. Erythema may be found in association with ulcers or chronic drainage from a surgical wound.^2,7

Histopathologic appearance varies, depending on the evolution of the disease and host immunologic status. Tuberculoid, palisading, and sarcoidlike granulomas; a diffuse infiltrate of histiocytic foamy cells; acute and chronic panniculitis; nonspecific chronic inflammation; cutaneous abscess; suppurative granuloma; and necrotizing folliculitis all can be seen.⁸ Immunosuppressed patients are less likely to form granulomas.⁶ Diagnosis often is delayed because acid-fast bacterial culture is not typically performed on skin biopsy specimens or surgical wound infections.⁷ Fortunately, a high index of suspicion in our patient’s case allowed for prompt diagnosis and expeditious management.

Management
Mycobacterium abscessus tends to be resistant to conventional antituberculous medications; overall, it is considered a highly drug-resistant pathogen that is difficult to treat.^9,10 Treatment usually requires 3 to 6 months of therapy, with oral clarithromycin considered the first-line agent for localized infection.⁵ Because cases of clarithromycin resistance have been reported in patients with M chelonae infection, caution is warranted when deciding between monotherapy or combination therapy.⁷ Multidrug resistance often necessitates prolonged IV therapy. Amikacin is the mostly commonly used IV agent for M abscessus infection. Adverse effects of treatment are common, often leading to a change in or discontinuation of therapy.¹¹

Our patient was initially given trimethoprim-sulfamethoxazole before being switched to doxycycline and levofloxacin prior to final results of susceptibility testing. Ultimately, due to the multidrug-resistant nature of M abscessus, clarithromycin was not a viable option. Therefore, the patient was administered tigecycline and amikacin through a peripherally inserted central catheter until symptoms fully resolved.

Surgery can be an important adjunctive measure for certain patients, especially those with a single lesion.⁷ Our patient did well with medical treatment alone.

Conclusion

Given the difficulty of treating skin and soft tissue infections caused by M abscessus and related mycobacteria, it is worth noting that these infections are increasingly caused by procedures generally considered to be minimally invasive. Microdermabrasion—performed at home in an unsterile environment and not by a trained medical professional—was the causal procedure in this case. An important consideration is whether clinicians can be comfortable with the use of these treatments at home or whether they should be advising patients against at-home treatments that have potentially serious complications.

Rosacea is an inflammatory skin condition that affects approximately 5% of the adult population, with the highest prevalence in Europe and North America.¹ Despite its prevalence, rosacea remains poorly understood from a pathophysiologic perspective, with no diagnostic laboratory markers.² Because diagnosis relies on clinical judgment, the nomenclature for describing and characterizing rosacea becomes paramount in ensuring that patients are given an accurate diagnosis and subsequent treatment. We review the shortfalls in the recent history of rosacea classification and discuss their implications.

Subtype to Phenotype Classification

In 2002, the National Rosacea Society (NRS) Expert Committee published a standardized classification schema for rosacea (Table).³ The authors described primary and secondary diagnostic criteria. The presence of 1 or more primary features in a central facial distribution was indicative of rosacea. Primary characteristics included flushing (transient erythema), nontransient erythema, papules and pustules, and telangiectasia. Secondary features, which could occur with or independently of primary features, included burning or stinging of the face, dry appearance, facial edema, ocular manifestations, peripheral (nonfacial) occurrence, phymatous changes, and red facial plaques. Whereas these features often present simultaneously in a characteristic pattern, they were grouped into 4 main subtypes—erythematotelangiectatic (ETR), papulopustular, phymatous, and ocular—and 1 variant, granulomatous rosacea.³

To enhance clinical and research applications of this categorization system as well as offer further standardization, the NRS released a supplementary clinical grading scorecard in 2004 in which each of the primary and secondary characteristics could be assigned a subjective severity score of absent, mild, moderate, or severe. The goal was that the subtype classification and clinical grading system, when used in conjunction with each other, would establish a common language for patients, clinicians, and researchers to describe and further investigate rosacea.⁴

The 2002 categorization system was certainly an impactful first step in the organization of rosacea. It was not without its critics, however, namely rosacea-oriented dermatologists who were concerned about its lack of specificity.^5-7 For instance, the NRS Expert Committee did not address the time frame for flushing, which typically has a long duration in rosacea patients, or for the nontransient erythema; telangiectasia secondary to heliodermatitis; or the often-observed periocular sparing. Additionally, the schema did not account for conditions such as gram-negative folliculitis (pustules characteristically located on the central face) or discuss the need to rule out carcinoid, mastocytosis, or connective-tissue disease, which can lead to nontransient facial erythema. Without strict definitions and exclusions, nonrosacea disorders could be incorrectly labeled as rosacea.

Beyond the lack of specificity, there was additional concern if a subtype system was the ideal way to capture disease presentation and severity. By subtyping, there was unnecessary division of interrelated disease into individual disorders; an individual’s clinical presentation might fall along a spectrum rather than within a discrete box.⁸

Furthermore, from a research standpoint, subtyping rosacea could hinder or confuse epidemiologic studies. For instance, if patients present with phenotypes from different subtypes, into which subtype would they fall?^8-10

The global ROSacea COnsensus (ROSCO) panel, comprising 17 international dermatologists and ophthalmologists, convened in 2016 to address this matter. The panel proposed a new system (published in 2017) based on individual phenotypes.⁹ In this new system, diagnostic features include persistent centrofacial erythema with periods of increased intensity and phymatous changes. Major features, which are diagnostic when there are at least 2, include flushing (transient erythema), inflammatory papules and pustules, centrofacial telangiectasia, and ocular manifestations. Each feature could then be graded on a severity spectrum independent of concurrent phenotypes (Table).⁸

The panel concluded that this system would provide a stronger foundation for standardization as new knowledge of rosacea continues to be elucidated.⁸ In support of their argument, ROSCO also released a treatment algorithm that depended on a phenotype scheme.¹¹ The panel emphasized that by focusing on individual lesions rather than a subtype encompassing many characteristics, treatment could be tailored to the patient. Using this à-la-carte therapy option, physicians could choose those rosacea aspects that are particularly concerning to the patient and manage only those aspects or overlap treatments to improve multiple aspects.¹¹

In 2017, 15 years after the original classification system was proposed, the NRS updated their classification system (published in 2018), taking into consideration some of the criticisms as well as new scientific data on rosacea. Similar to the schema proposed by ROSCO, this system was based on phenotype. Inclusion and exclusion criteria were more robust in this update compared to the original classification in 2002. The criteria provide a timeline for transient flushing—it must occur within seconds or minutes in response to a neurovascular stimulant—and state that it is characteristically prolonged (Table).¹²

However, the Expert Committee still did not define either the length of time of flushing or nontransient erythema. It also did not specify convex surfaces of the face with periocular sparing as the characteristic pattern or provide additional information on how photoaging fits into the definition. The updated classification stated that centrofacial erythema must not be from cutaneous lupus or seborrheic eczema, and steroid-induced rosacea was still excluded.¹² However, there is still the need to exclude other systemic conditions, such as mastocytosis, carcinoid, polycythemia vera, and dermatomyositis. Therefore, the potential for subjective error and inclusion of nonrosacea diseases persists.

A critical change was elimination of the granulomatous rosacea variant. In 2002, this variant was defined by monomorphic, yellow-brown to red papules and nodules that led to scarring. This variant, however, did not share the commonalities of the other subtypes, including persistent facial erythema, limitation to convex surfaces, periocular sparing, and transient flushing.^3,13 At the time, Crawford et al⁶ proposed that the variant be recategorized as granulomatous facial dermatitis. In the updated NRS classification, this variant and phenotypic description was eliminated from the schema.¹² It is unclear if it was removed because of these discrepancies or if the NRS panel felt it had a distinct pathogenesis from the proposed rosacea pathophysiology; however, we applaud this change.

Subtype Progression

Both the ROSCO and NRS classification schemes mention progression between the various phenotypes,^10,12 suggesting that rosacea phenotypes exist along a continuum, progressing and regressing with disease severity. The main study addressing this point was based on the self-reported retrospective patient memory of disease features in rosacea patients. The authors used a modified criterion of centrofacial erythema alone to define ETR; therefore, a person who began their disease with this finding but then acquired inflammatory lesions or phymas was defined as progressing along a spectrum.¹⁴ Given that persistent erythema of convex surfaces of the face is common in all subtypes, we do not find it surprising that the authors found (using their modified criteria) that ETR appeared to progress to papulopustular and phymatous subtypes in a small number of patients. We strongly disagree with their interpretation and conclusion.

In our experience, ETR patients have fine textured skin without sebaceous quality or a history of extensive acne (Figure 1). Flushing is common and usually lasts 10 minutes to 1 hour. There might be concurrent burning or stinging; however, there is no associated sweating, lightheadedness, palpitations, or diagnostic laboratory findings, which distinguishes ETR from other common causes of flushing. The persistent centrofacial erythema involves convex surfaces, spares periocular skin, and can be best defined as present for longer than 3 months.

Implications and Future Directions

We present an overview of 2 rosacea classification systems, hoping to stimulate further refinement. Looking forward, there are many directions for further investigation into the pathophysiology of rosacea. From a genetic standpoint, there needs to be continued molecular and epidemiologic data to determine the underlying genetic contributions to disease.

There has been some progress in the realm of understanding the mechanisms of inflammation; we urge further investigation to elucidate how “subclinical neuroinflammation” might lead to glandular hyperplasia.¹² We also see value in examining the genetic and hormonal contributions to phymas, as they may be different than those seen in the ETR-type patients. Last, more studies focusing on comorbidities that contribute to or arise from rosacea are welcomed.

The ultimate goal is to develop a classification system that integrates clinical descriptions, pathophysiologic mechanisms, and benchmark indicators of disease. Only then can we have a true gold standard for the diagnosis of rosacea, one that allows for improved personalized treatment and better outcomes.

Rosacea is an inflammatory skin condition that affects approximately 5% of the adult population, with the highest prevalence in Europe and North America.¹ Despite its prevalence, rosacea remains poorly understood from a pathophysiologic perspective, with no diagnostic laboratory markers.² Because diagnosis relies on clinical judgment, the nomenclature for describing and characterizing rosacea becomes paramount in ensuring that patients are given an accurate diagnosis and subsequent treatment. We review the shortfalls in the recent history of rosacea classification and discuss their implications.

Subtype to Phenotype Classification

In 2002, the National Rosacea Society (NRS) Expert Committee published a standardized classification schema for rosacea (Table).³ The authors described primary and secondary diagnostic criteria. The presence of 1 or more primary features in a central facial distribution was indicative of rosacea. Primary characteristics included flushing (transient erythema), nontransient erythema, papules and pustules, and telangiectasia. Secondary features, which could occur with or independently of primary features, included burning or stinging of the face, dry appearance, facial edema, ocular manifestations, peripheral (nonfacial) occurrence, phymatous changes, and red facial plaques. Whereas these features often present simultaneously in a characteristic pattern, they were grouped into 4 main subtypes—erythematotelangiectatic (ETR), papulopustular, phymatous, and ocular—and 1 variant, granulomatous rosacea.³

To enhance clinical and research applications of this categorization system as well as offer further standardization, the NRS released a supplementary clinical grading scorecard in 2004 in which each of the primary and secondary characteristics could be assigned a subjective severity score of absent, mild, moderate, or severe. The goal was that the subtype classification and clinical grading system, when used in conjunction with each other, would establish a common language for patients, clinicians, and researchers to describe and further investigate rosacea.⁴

The 2002 categorization system was certainly an impactful first step in the organization of rosacea. It was not without its critics, however, namely rosacea-oriented dermatologists who were concerned about its lack of specificity.^5-7 For instance, the NRS Expert Committee did not address the time frame for flushing, which typically has a long duration in rosacea patients, or for the nontransient erythema; telangiectasia secondary to heliodermatitis; or the often-observed periocular sparing. Additionally, the schema did not account for conditions such as gram-negative folliculitis (pustules characteristically located on the central face) or discuss the need to rule out carcinoid, mastocytosis, or connective-tissue disease, which can lead to nontransient facial erythema. Without strict definitions and exclusions, nonrosacea disorders could be incorrectly labeled as rosacea.

Beyond the lack of specificity, there was additional concern if a subtype system was the ideal way to capture disease presentation and severity. By subtyping, there was unnecessary division of interrelated disease into individual disorders; an individual’s clinical presentation might fall along a spectrum rather than within a discrete box.⁸

Furthermore, from a research standpoint, subtyping rosacea could hinder or confuse epidemiologic studies. For instance, if patients present with phenotypes from different subtypes, into which subtype would they fall?^8-10

The global ROSacea COnsensus (ROSCO) panel, comprising 17 international dermatologists and ophthalmologists, convened in 2016 to address this matter. The panel proposed a new system (published in 2017) based on individual phenotypes.⁹ In this new system, diagnostic features include persistent centrofacial erythema with periods of increased intensity and phymatous changes. Major features, which are diagnostic when there are at least 2, include flushing (transient erythema), inflammatory papules and pustules, centrofacial telangiectasia, and ocular manifestations. Each feature could then be graded on a severity spectrum independent of concurrent phenotypes (Table).⁸

The panel concluded that this system would provide a stronger foundation for standardization as new knowledge of rosacea continues to be elucidated.⁸ In support of their argument, ROSCO also released a treatment algorithm that depended on a phenotype scheme.¹¹ The panel emphasized that by focusing on individual lesions rather than a subtype encompassing many characteristics, treatment could be tailored to the patient. Using this à-la-carte therapy option, physicians could choose those rosacea aspects that are particularly concerning to the patient and manage only those aspects or overlap treatments to improve multiple aspects.¹¹

In 2017, 15 years after the original classification system was proposed, the NRS updated their classification system (published in 2018), taking into consideration some of the criticisms as well as new scientific data on rosacea. Similar to the schema proposed by ROSCO, this system was based on phenotype. Inclusion and exclusion criteria were more robust in this update compared to the original classification in 2002. The criteria provide a timeline for transient flushing—it must occur within seconds or minutes in response to a neurovascular stimulant—and state that it is characteristically prolonged (Table).¹²

However, the Expert Committee still did not define either the length of time of flushing or nontransient erythema. It also did not specify convex surfaces of the face with periocular sparing as the characteristic pattern or provide additional information on how photoaging fits into the definition. The updated classification stated that centrofacial erythema must not be from cutaneous lupus or seborrheic eczema, and steroid-induced rosacea was still excluded.¹² However, there is still the need to exclude other systemic conditions, such as mastocytosis, carcinoid, polycythemia vera, and dermatomyositis. Therefore, the potential for subjective error and inclusion of nonrosacea diseases persists.

A critical change was elimination of the granulomatous rosacea variant. In 2002, this variant was defined by monomorphic, yellow-brown to red papules and nodules that led to scarring. This variant, however, did not share the commonalities of the other subtypes, including persistent facial erythema, limitation to convex surfaces, periocular sparing, and transient flushing.^3,13 At the time, Crawford et al⁶ proposed that the variant be recategorized as granulomatous facial dermatitis. In the updated NRS classification, this variant and phenotypic description was eliminated from the schema.¹² It is unclear if it was removed because of these discrepancies or if the NRS panel felt it had a distinct pathogenesis from the proposed rosacea pathophysiology; however, we applaud this change.

Subtype Progression

Both the ROSCO and NRS classification schemes mention progression between the various phenotypes,^10,12 suggesting that rosacea phenotypes exist along a continuum, progressing and regressing with disease severity. The main study addressing this point was based on the self-reported retrospective patient memory of disease features in rosacea patients. The authors used a modified criterion of centrofacial erythema alone to define ETR; therefore, a person who began their disease with this finding but then acquired inflammatory lesions or phymas was defined as progressing along a spectrum.¹⁴ Given that persistent erythema of convex surfaces of the face is common in all subtypes, we do not find it surprising that the authors found (using their modified criteria) that ETR appeared to progress to papulopustular and phymatous subtypes in a small number of patients. We strongly disagree with their interpretation and conclusion.

In our experience, ETR patients have fine textured skin without sebaceous quality or a history of extensive acne (Figure 1). Flushing is common and usually lasts 10 minutes to 1 hour. There might be concurrent burning or stinging; however, there is no associated sweating, lightheadedness, palpitations, or diagnostic laboratory findings, which distinguishes ETR from other common causes of flushing. The persistent centrofacial erythema involves convex surfaces, spares periocular skin, and can be best defined as present for longer than 3 months.

Implications and Future Directions

We present an overview of 2 rosacea classification systems, hoping to stimulate further refinement. Looking forward, there are many directions for further investigation into the pathophysiology of rosacea. From a genetic standpoint, there needs to be continued molecular and epidemiologic data to determine the underlying genetic contributions to disease.

There has been some progress in the realm of understanding the mechanisms of inflammation; we urge further investigation to elucidate how “subclinical neuroinflammation” might lead to glandular hyperplasia.¹² We also see value in examining the genetic and hormonal contributions to phymas, as they may be different than those seen in the ETR-type patients. Last, more studies focusing on comorbidities that contribute to or arise from rosacea are welcomed.

The ultimate goal is to develop a classification system that integrates clinical descriptions, pathophysiologic mechanisms, and benchmark indicators of disease. Only then can we have a true gold standard for the diagnosis of rosacea, one that allows for improved personalized treatment and better outcomes.

Rosacea is an inflammatory skin condition that affects approximately 5% of the adult population, with the highest prevalence in Europe and North America.¹ Despite its prevalence, rosacea remains poorly understood from a pathophysiologic perspective, with no diagnostic laboratory markers.² Because diagnosis relies on clinical judgment, the nomenclature for describing and characterizing rosacea becomes paramount in ensuring that patients are given an accurate diagnosis and subsequent treatment. We review the shortfalls in the recent history of rosacea classification and discuss their implications.

Subtype to Phenotype Classification

In 2002, the National Rosacea Society (NRS) Expert Committee published a standardized classification schema for rosacea (Table).³ The authors described primary and secondary diagnostic criteria. The presence of 1 or more primary features in a central facial distribution was indicative of rosacea. Primary characteristics included flushing (transient erythema), nontransient erythema, papules and pustules, and telangiectasia. Secondary features, which could occur with or independently of primary features, included burning or stinging of the face, dry appearance, facial edema, ocular manifestations, peripheral (nonfacial) occurrence, phymatous changes, and red facial plaques. Whereas these features often present simultaneously in a characteristic pattern, they were grouped into 4 main subtypes—erythematotelangiectatic (ETR), papulopustular, phymatous, and ocular—and 1 variant, granulomatous rosacea.³

To enhance clinical and research applications of this categorization system as well as offer further standardization, the NRS released a supplementary clinical grading scorecard in 2004 in which each of the primary and secondary characteristics could be assigned a subjective severity score of absent, mild, moderate, or severe. The goal was that the subtype classification and clinical grading system, when used in conjunction with each other, would establish a common language for patients, clinicians, and researchers to describe and further investigate rosacea.⁴

The 2002 categorization system was certainly an impactful first step in the organization of rosacea. It was not without its critics, however, namely rosacea-oriented dermatologists who were concerned about its lack of specificity.^5-7 For instance, the NRS Expert Committee did not address the time frame for flushing, which typically has a long duration in rosacea patients, or for the nontransient erythema; telangiectasia secondary to heliodermatitis; or the often-observed periocular sparing. Additionally, the schema did not account for conditions such as gram-negative folliculitis (pustules characteristically located on the central face) or discuss the need to rule out carcinoid, mastocytosis, or connective-tissue disease, which can lead to nontransient facial erythema. Without strict definitions and exclusions, nonrosacea disorders could be incorrectly labeled as rosacea.

Beyond the lack of specificity, there was additional concern if a subtype system was the ideal way to capture disease presentation and severity. By subtyping, there was unnecessary division of interrelated disease into individual disorders; an individual’s clinical presentation might fall along a spectrum rather than within a discrete box.⁸

Furthermore, from a research standpoint, subtyping rosacea could hinder or confuse epidemiologic studies. For instance, if patients present with phenotypes from different subtypes, into which subtype would they fall?^8-10

The global ROSacea COnsensus (ROSCO) panel, comprising 17 international dermatologists and ophthalmologists, convened in 2016 to address this matter. The panel proposed a new system (published in 2017) based on individual phenotypes.⁹ In this new system, diagnostic features include persistent centrofacial erythema with periods of increased intensity and phymatous changes. Major features, which are diagnostic when there are at least 2, include flushing (transient erythema), inflammatory papules and pustules, centrofacial telangiectasia, and ocular manifestations. Each feature could then be graded on a severity spectrum independent of concurrent phenotypes (Table).⁸

The panel concluded that this system would provide a stronger foundation for standardization as new knowledge of rosacea continues to be elucidated.⁸ In support of their argument, ROSCO also released a treatment algorithm that depended on a phenotype scheme.¹¹ The panel emphasized that by focusing on individual lesions rather than a subtype encompassing many characteristics, treatment could be tailored to the patient. Using this à-la-carte therapy option, physicians could choose those rosacea aspects that are particularly concerning to the patient and manage only those aspects or overlap treatments to improve multiple aspects.¹¹

In 2017, 15 years after the original classification system was proposed, the NRS updated their classification system (published in 2018), taking into consideration some of the criticisms as well as new scientific data on rosacea. Similar to the schema proposed by ROSCO, this system was based on phenotype. Inclusion and exclusion criteria were more robust in this update compared to the original classification in 2002. The criteria provide a timeline for transient flushing—it must occur within seconds or minutes in response to a neurovascular stimulant—and state that it is characteristically prolonged (Table).¹²

However, the Expert Committee still did not define either the length of time of flushing or nontransient erythema. It also did not specify convex surfaces of the face with periocular sparing as the characteristic pattern or provide additional information on how photoaging fits into the definition. The updated classification stated that centrofacial erythema must not be from cutaneous lupus or seborrheic eczema, and steroid-induced rosacea was still excluded.¹² However, there is still the need to exclude other systemic conditions, such as mastocytosis, carcinoid, polycythemia vera, and dermatomyositis. Therefore, the potential for subjective error and inclusion of nonrosacea diseases persists.

A critical change was elimination of the granulomatous rosacea variant. In 2002, this variant was defined by monomorphic, yellow-brown to red papules and nodules that led to scarring. This variant, however, did not share the commonalities of the other subtypes, including persistent facial erythema, limitation to convex surfaces, periocular sparing, and transient flushing.^3,13 At the time, Crawford et al⁶ proposed that the variant be recategorized as granulomatous facial dermatitis. In the updated NRS classification, this variant and phenotypic description was eliminated from the schema.¹² It is unclear if it was removed because of these discrepancies or if the NRS panel felt it had a distinct pathogenesis from the proposed rosacea pathophysiology; however, we applaud this change.

Subtype Progression

Both the ROSCO and NRS classification schemes mention progression between the various phenotypes,^10,12 suggesting that rosacea phenotypes exist along a continuum, progressing and regressing with disease severity. The main study addressing this point was based on the self-reported retrospective patient memory of disease features in rosacea patients. The authors used a modified criterion of centrofacial erythema alone to define ETR; therefore, a person who began their disease with this finding but then acquired inflammatory lesions or phymas was defined as progressing along a spectrum.¹⁴ Given that persistent erythema of convex surfaces of the face is common in all subtypes, we do not find it surprising that the authors found (using their modified criteria) that ETR appeared to progress to papulopustular and phymatous subtypes in a small number of patients. We strongly disagree with their interpretation and conclusion.

In our experience, ETR patients have fine textured skin without sebaceous quality or a history of extensive acne (Figure 1). Flushing is common and usually lasts 10 minutes to 1 hour. There might be concurrent burning or stinging; however, there is no associated sweating, lightheadedness, palpitations, or diagnostic laboratory findings, which distinguishes ETR from other common causes of flushing. The persistent centrofacial erythema involves convex surfaces, spares periocular skin, and can be best defined as present for longer than 3 months.

Implications and Future Directions

We present an overview of 2 rosacea classification systems, hoping to stimulate further refinement. Looking forward, there are many directions for further investigation into the pathophysiology of rosacea. From a genetic standpoint, there needs to be continued molecular and epidemiologic data to determine the underlying genetic contributions to disease.

There has been some progress in the realm of understanding the mechanisms of inflammation; we urge further investigation to elucidate how “subclinical neuroinflammation” might lead to glandular hyperplasia.¹² We also see value in examining the genetic and hormonal contributions to phymas, as they may be different than those seen in the ETR-type patients. Last, more studies focusing on comorbidities that contribute to or arise from rosacea are welcomed.

The ultimate goal is to develop a classification system that integrates clinical descriptions, pathophysiologic mechanisms, and benchmark indicators of disease. Only then can we have a true gold standard for the diagnosis of rosacea, one that allows for improved personalized treatment and better outcomes.

In the last 20 years, the incidence of acne lesions in adults has markedly increased. ¹ Acne affects adults (individuals older than 25 years) and is no longer a condition limited to adolescents and young adults (individuals younger than 25 years). According to Dreno et al, ² the accepted age threshold for the onset of adult acne is 25 years. ^1-3 In 2013, the term adult acne was defined. ² Among patients with adult acne, there are 2 subtypes: (1) persistent adult acne, which is a continuation or recurrence of adolescent acne, affecting approximately 80% of patients, and (2) late-onset acne, affecting approximately 20% of patients. ⁴

Clinical symptoms of adult acne and available treatment modalities have been explored in the literature. Daily clinical experience shows that additional difficulties involved in the management of adult acne patients are related mainly to a high therapeutic failure rate in acne patients older than 25 years. ⁵ Persistent adult acne seems to be noteworthy because it causes long-term symptoms, and patients experience uncontrollable recurrences.

It is believed that adult acne often is resistant to treatment. ² Adult skin is more sensitive to topical agents, leading to more irritation by medications intended for external use and cosmetics. ⁶ Scars in these patients are a frequent and undesirable consequence. ³

Effective treatment of acne encompasses oral antibiotics, topical and systemic retinoids, and oral contraceptive pills (OCPs). For years, oral subantimicrobial doses of cyclines have been recommended for acne treatment. Topical and oral retinoids have been successfully used for more than 30 years as important therapeutic options. ⁷ More recent evidence-based guidelines for acne issued by the American Academy of Dermatology ⁸ and the European Dermatology Forum ⁹ also show that retinoids play an important role in acne therapy. Their anti-inflammatory activity acts against comedones and their precursors (microcomedones). Successful antiacne therapy not only achieves a smooth face without comedones but also minimizes scar formation, postinflammatory discoloration, and long-lasting postinflammatory erythema. ¹⁰ Oral contraceptives have a mainly antiseborrheic effect. ¹¹

Our study sought to analyze the potential influence of therapy during adolescent acne on patients who later developed adult acne. Particular attention was given to the use of oral antibiotics, isotretinoin, and topical retinoids for adolescent acne and their potential role in diminishing scar formation in adult acne.

Materials and Methods

Patient Demographics and Selection
A population-based study of Polish patients with adult acne was conducted. Patients were included in the study group on a consecutive basis from among those who visited our outpatient dermatology center from May 2015 to January 2016. A total of 111 patients (101 women [90.99%] and 10 men [9.01%]) were examined. The study group comprised patients aged 25 years and older who were treated for adult acne (20 patients [18.02%] were aged 25–29 years, 61 [54.95%] were aged 30–39 years, and 30 [27.02%] were 40 years or older).

The following inclusion criteria were used: observation period of at least 6 months in our dermatologic center for patients diagnosed with adult acne, at least 2 dermatologic visits for adult acne prior to the study, written informed consent for study participation and data processing (the aim of the study was explained to each participant by a dermatologist), and age 25 years or older. Exclusion criteria included those who were younger than 25 years, those who had only 1 dermatologic visit at our dermatology center, and those who were unwilling to participate or did not provide written informed consent. Our study was conducted according to Good Clinical Practice.

Data Collection
To obtain data with the highest degree of reliability, 3 sources of information were used: (1) a detailed medical interview conducted by one experienced dermatologist (E.C.) at our dermatology center at the first visit in all study participants, (2) a clinical examination that yielded results necessary for the assessment of scars using a method outlined by Jacob et al, ¹² and (3) information included in available medical records. These data were then statistically analyzed.

Statistical Analysis
The results were presented as frequency plots, and a Fisher exact test was conducted to obtain a statistical comparison of the distributions of analyzed data. Unless otherwise indicated, 5% was adopted as the significance level. The statistical analysis was performed using Stata 14 software (StataCorp LLC, College Station, Texas).

Results

Incidence of Different Forms of Adult Acne
To analyze the onset of acne, patients were categorized into 1 of 2 groups: those with persistent adult acne (81.98%) and those with late-onset adult acne (ie, developed after 25 years of age)(18.02%).

Age at Initiation of Dermatologic Treatment
Of the patients with persistent adult acne, 31.87% first visited a dermatologist the same year that the first acne lesions appeared, 36.26% postponed the first visit by at least 5 years (Figure 1), and 23.08% started treatment at least 10 years after acne first appeared. Among patients with persistent adult acne, 76.92% began dermatologic treatment before 25 years of age, and 23.08% began treatment after 25 years of age. Of the latter, 28.57% did not start therapy until they were older than 35 years.

Severity of Adolescent Acne
In the persistent adult acne group, the severity of adolescent acne was assessed during the medical interview as well as detailed histories in medical records. The activity of acne was evaluated at 2-year intervals with the use of a 10-point scale: 1 to 3 points indicated mild acne (7.69% of patients), 4 to 6 points indicated moderate acne (24.18%), and 7 to 10 points indicated severe acne (68.13%).

Treatment of Persistent Acne in Adolescence
Treatment was comprised of oral therapy with antibiotics, isotretinoin, and/or application of topical retinoids (sometimes supported with OCPs). Monotherapy was the standard of treatment more than 25 years ago when patients with persistent adult acne were treated as adolescents or young adults. As many as 43.96% of patients with persistent adult acne did not receive any of these therapies before 25 years of age; rather, they used antiacne cosmetics or beauty procedures. Furthermore, 50.55% of patients were treated with oral antibiotics (Figure 2). Topical retinoids were used in 19.78% of patients and isotretinoin was used in 16.48%. Incidentally, OCPs were given to 26.5%. In the course of adolescent acne, 31.87% of patients received 2 to 4 courses of treatment with either antibiotics or retinoids (oral or topical), and 5.49% were treated with 5 or more courses of treatment (Figure 3). The analysis of each treatment revealed that only 1 patient received 4 courses of isotretinoin. Five courses of oral antibiotics were given in 1 patient, and 3 courses of topical retinoids were given in the same patient.

Topical Retinoids
In an analysis of the number of treatments with topical retinoids completed by patients with persistent adult acne, it was established that 80.22% of patients never used topical retinoids for acne during adolescence. Additionally, 12.08% of these patients completed 1 course of treatment, and 7.69% completed 2 to 4 treatments. However, after 25 years of age, only 25.27% of the patients with persistent adult acne were not treated with topical retinoids, and 35.16% completed more than 2 courses of treatment.

Duration of Treatment
Because adult acne is a chronic disease, the mean number of years that patients received treatment over the disease course was analyzed. In the case of persistent adult acne, the mean duration of treatment, including therapy received during adolescence, was more than 13 years. At the time of the study, more than 30% of patients had been undergoing treatment of adult acne for more than 20 years. Scars— The proportion of patients with persistent adult acne who experienced scarring was evaluated. In the persistent adult acne group, scars were identified in 53.85% of patients. Scars appeared only during adolescence in 26.37% of patients with persistent adult acne, scars appeared only after 25 years of age in 21.97% of patients, and scars appeared in adolescence as well as adulthood in 30.77% of patients.

In an analysis of patients with persistent adult acne who experienced scarring after 25 years of age, the proportion of patients with untreated adolescent acne and those who were treated with antibiotics only was not significantly different (60% vs 64%; P = .478)(Table). The inclusion of topical retinoids into treatment decreased the proportion of scars (isotretinoin: 20%, P = .009; topical retinoids: 38.89%, P = .114).

Comment

Persistent Adult Acne
Patients with symptoms of persistent adult acne represented 81.98% of the study population, which was similar to a 1999 study by Goulden et al, ¹ a 2001 study by Shaw and White, ¹³ and a 2009 report by Schmidt et al. ¹⁴ Of these patients with persistent adult acne, 23.08% initiated therapy after 25 years of age, and 23.08% started treatment at least 10 years after acne lesions first appeared. However, it is noteworthy that 68.13% of all patients with persistent adult acne assessed their disease as severe.

Treatment Modalities for Adult Acne
Over the last 5 years, some researchers have attempted to make recommendations for the treatment of adult acne based on standards adopted for the treatment of adolescent acne. ^2,9,15 First-line treatment of patients with adult comedonal acne is topical retinoids. ⁹ The recommended treatment of mild to moderate adult inflammatory acne involves topical drugs, including retinoids, azelaic acid, or benzoyl peroxide, or oral medications, including antibiotics, OCPs, or antiandrogens. In severe inflammatory acne, the recommended treatment involves oral isotretinoin or combined therapies; the latter seems to be the most effective. ¹⁶ Furthermore, this therapy has been adjusted to the patient’s current clinical condition; general individual sensitivity of the skin to irritation and the risk for irritant activity of topical medications; and life situation, such as planned pregnancies and intended use of OCPs due to the risk for teratogenic effects of drugs. ¹⁷

To assess available treatment modalities, oral therapy with antibiotics or isotretinoin as well as topical retinoids were selected for our analysis. It is difficult to determine an exclusive impact of OCPs as acne treatment; according to our study, many female patients use hormone therapy for other medical conditions or contraception, and only a small proportion of these patients are prescribed hormone treatment for acne. We found that 43.96% of patients with persistent adult acne underwent no treatment with antibiotics, isotretinoin, or topical retinoids in adolescence. Patients who did not receive any of these treatments came only for single visits to a dermatologist, did not comply to a recommended therapy, or used only cosmetics or beauty procedures. We found that 80.22% of patients with persistent adult acne never used topical retinoids during adolescence and did not receive maintenance therapy, which may be attributed to the fact that there were no strict recommendations regarding retinoid treatment when these patients were adolescents or young adults. Published data indicate that retinoid use for acne treatment is not common. ¹⁸ Conversely, among patients older than 25 years with late-onset adult acne, there was only 1 patient (ie, < 1%) who had never received any oral antibiotic or isotretinoin treatment or therapy with topical retinoids. The reason for the lack of medical treatment is unknown. Only 25.27% of patients were not treated with topical retinoids, and 35.16% completed at least 2 courses of treatment. The use of topical retinoids for the treatment of persistent and late-onset adult acne may be the result of the spread of knowledge among dermatologists acquired over the last 25 years.

Acne Scarring
The worst complication of acne is scarring. Scars develop for the duration of the disease, during both adolescent and adult acne. In the group with persistent adult acne, scarring was found in 53.85% of patients. Scar formation has been previously reported as a common complication of acne. ¹⁹ The effects of skin lesions that remain after acne are not only limited to impaired cosmetic appearance; they also negatively affect mental health and impair quality of life. ²⁰ The aim of our study was to analyze types of treatment for adolescent acne in patients who later had persistent adult acne. Postacne scars observed later are objective evidence of the severity of disease. We found that using oral antibiotics did not diminish the number of scars among persistent adult acne patients in adulthood. In contrast, isotretinoin or topical retinoid treatment during adolescence decreased the risk for scars occurring during adulthood. In our opinion, these findings emphasize the role of this type of treatment among adolescents or young adults. The decrease of scar formation in adult acne due to retinoid treatment in adolescence indirectly justifies the role of maintenance therapy with topical retinoids. ^21,22

In the last 20 years, the incidence of acne lesions in adults has markedly increased. ¹ Acne affects adults (individuals older than 25 years) and is no longer a condition limited to adolescents and young adults (individuals younger than 25 years). According to Dreno et al, ² the accepted age threshold for the onset of adult acne is 25 years. ^1-3 In 2013, the term adult acne was defined. ² Among patients with adult acne, there are 2 subtypes: (1) persistent adult acne, which is a continuation or recurrence of adolescent acne, affecting approximately 80% of patients, and (2) late-onset acne, affecting approximately 20% of patients. ⁴

Clinical symptoms of adult acne and available treatment modalities have been explored in the literature. Daily clinical experience shows that additional difficulties involved in the management of adult acne patients are related mainly to a high therapeutic failure rate in acne patients older than 25 years. ⁵ Persistent adult acne seems to be noteworthy because it causes long-term symptoms, and patients experience uncontrollable recurrences.

It is believed that adult acne often is resistant to treatment. ² Adult skin is more sensitive to topical agents, leading to more irritation by medications intended for external use and cosmetics. ⁶ Scars in these patients are a frequent and undesirable consequence. ³

Effective treatment of acne encompasses oral antibiotics, topical and systemic retinoids, and oral contraceptive pills (OCPs). For years, oral subantimicrobial doses of cyclines have been recommended for acne treatment. Topical and oral retinoids have been successfully used for more than 30 years as important therapeutic options. ⁷ More recent evidence-based guidelines for acne issued by the American Academy of Dermatology ⁸ and the European Dermatology Forum ⁹ also show that retinoids play an important role in acne therapy. Their anti-inflammatory activity acts against comedones and their precursors (microcomedones). Successful antiacne therapy not only achieves a smooth face without comedones but also minimizes scar formation, postinflammatory discoloration, and long-lasting postinflammatory erythema. ¹⁰ Oral contraceptives have a mainly antiseborrheic effect. ¹¹

Our study sought to analyze the potential influence of therapy during adolescent acne on patients who later developed adult acne. Particular attention was given to the use of oral antibiotics, isotretinoin, and topical retinoids for adolescent acne and their potential role in diminishing scar formation in adult acne.

Materials and Methods

Patient Demographics and Selection
A population-based study of Polish patients with adult acne was conducted. Patients were included in the study group on a consecutive basis from among those who visited our outpatient dermatology center from May 2015 to January 2016. A total of 111 patients (101 women [90.99%] and 10 men [9.01%]) were examined. The study group comprised patients aged 25 years and older who were treated for adult acne (20 patients [18.02%] were aged 25–29 years, 61 [54.95%] were aged 30–39 years, and 30 [27.02%] were 40 years or older).

The following inclusion criteria were used: observation period of at least 6 months in our dermatologic center for patients diagnosed with adult acne, at least 2 dermatologic visits for adult acne prior to the study, written informed consent for study participation and data processing (the aim of the study was explained to each participant by a dermatologist), and age 25 years or older. Exclusion criteria included those who were younger than 25 years, those who had only 1 dermatologic visit at our dermatology center, and those who were unwilling to participate or did not provide written informed consent. Our study was conducted according to Good Clinical Practice.

Data Collection
To obtain data with the highest degree of reliability, 3 sources of information were used: (1) a detailed medical interview conducted by one experienced dermatologist (E.C.) at our dermatology center at the first visit in all study participants, (2) a clinical examination that yielded results necessary for the assessment of scars using a method outlined by Jacob et al, ¹² and (3) information included in available medical records. These data were then statistically analyzed.

Statistical Analysis
The results were presented as frequency plots, and a Fisher exact test was conducted to obtain a statistical comparison of the distributions of analyzed data. Unless otherwise indicated, 5% was adopted as the significance level. The statistical analysis was performed using Stata 14 software (StataCorp LLC, College Station, Texas).

Results

Incidence of Different Forms of Adult Acne
To analyze the onset of acne, patients were categorized into 1 of 2 groups: those with persistent adult acne (81.98%) and those with late-onset adult acne (ie, developed after 25 years of age)(18.02%).

Age at Initiation of Dermatologic Treatment
Of the patients with persistent adult acne, 31.87% first visited a dermatologist the same year that the first acne lesions appeared, 36.26% postponed the first visit by at least 5 years (Figure 1), and 23.08% started treatment at least 10 years after acne first appeared. Among patients with persistent adult acne, 76.92% began dermatologic treatment before 25 years of age, and 23.08% began treatment after 25 years of age. Of the latter, 28.57% did not start therapy until they were older than 35 years.

Severity of Adolescent Acne
In the persistent adult acne group, the severity of adolescent acne was assessed during the medical interview as well as detailed histories in medical records. The activity of acne was evaluated at 2-year intervals with the use of a 10-point scale: 1 to 3 points indicated mild acne (7.69% of patients), 4 to 6 points indicated moderate acne (24.18%), and 7 to 10 points indicated severe acne (68.13%).

Treatment of Persistent Acne in Adolescence
Treatment was comprised of oral therapy with antibiotics, isotretinoin, and/or application of topical retinoids (sometimes supported with OCPs). Monotherapy was the standard of treatment more than 25 years ago when patients with persistent adult acne were treated as adolescents or young adults. As many as 43.96% of patients with persistent adult acne did not receive any of these therapies before 25 years of age; rather, they used antiacne cosmetics or beauty procedures. Furthermore, 50.55% of patients were treated with oral antibiotics (Figure 2). Topical retinoids were used in 19.78% of patients and isotretinoin was used in 16.48%. Incidentally, OCPs were given to 26.5%. In the course of adolescent acne, 31.87% of patients received 2 to 4 courses of treatment with either antibiotics or retinoids (oral or topical), and 5.49% were treated with 5 or more courses of treatment (Figure 3). The analysis of each treatment revealed that only 1 patient received 4 courses of isotretinoin. Five courses of oral antibiotics were given in 1 patient, and 3 courses of topical retinoids were given in the same patient.

Topical Retinoids
In an analysis of the number of treatments with topical retinoids completed by patients with persistent adult acne, it was established that 80.22% of patients never used topical retinoids for acne during adolescence. Additionally, 12.08% of these patients completed 1 course of treatment, and 7.69% completed 2 to 4 treatments. However, after 25 years of age, only 25.27% of the patients with persistent adult acne were not treated with topical retinoids, and 35.16% completed more than 2 courses of treatment.

Duration of Treatment
Because adult acne is a chronic disease, the mean number of years that patients received treatment over the disease course was analyzed. In the case of persistent adult acne, the mean duration of treatment, including therapy received during adolescence, was more than 13 years. At the time of the study, more than 30% of patients had been undergoing treatment of adult acne for more than 20 years. Scars— The proportion of patients with persistent adult acne who experienced scarring was evaluated. In the persistent adult acne group, scars were identified in 53.85% of patients. Scars appeared only during adolescence in 26.37% of patients with persistent adult acne, scars appeared only after 25 years of age in 21.97% of patients, and scars appeared in adolescence as well as adulthood in 30.77% of patients.

In an analysis of patients with persistent adult acne who experienced scarring after 25 years of age, the proportion of patients with untreated adolescent acne and those who were treated with antibiotics only was not significantly different (60% vs 64%; P = .478)(Table). The inclusion of topical retinoids into treatment decreased the proportion of scars (isotretinoin: 20%, P = .009; topical retinoids: 38.89%, P = .114).

Comment

Persistent Adult Acne
Patients with symptoms of persistent adult acne represented 81.98% of the study population, which was similar to a 1999 study by Goulden et al, ¹ a 2001 study by Shaw and White, ¹³ and a 2009 report by Schmidt et al. ¹⁴ Of these patients with persistent adult acne, 23.08% initiated therapy after 25 years of age, and 23.08% started treatment at least 10 years after acne lesions first appeared. However, it is noteworthy that 68.13% of all patients with persistent adult acne assessed their disease as severe.

Treatment Modalities for Adult Acne
Over the last 5 years, some researchers have attempted to make recommendations for the treatment of adult acne based on standards adopted for the treatment of adolescent acne. ^2,9,15 First-line treatment of patients with adult comedonal acne is topical retinoids. ⁹ The recommended treatment of mild to moderate adult inflammatory acne involves topical drugs, including retinoids, azelaic acid, or benzoyl peroxide, or oral medications, including antibiotics, OCPs, or antiandrogens. In severe inflammatory acne, the recommended treatment involves oral isotretinoin or combined therapies; the latter seems to be the most effective. ¹⁶ Furthermore, this therapy has been adjusted to the patient’s current clinical condition; general individual sensitivity of the skin to irritation and the risk for irritant activity of topical medications; and life situation, such as planned pregnancies and intended use of OCPs due to the risk for teratogenic effects of drugs. ¹⁷

To assess available treatment modalities, oral therapy with antibiotics or isotretinoin as well as topical retinoids were selected for our analysis. It is difficult to determine an exclusive impact of OCPs as acne treatment; according to our study, many female patients use hormone therapy for other medical conditions or contraception, and only a small proportion of these patients are prescribed hormone treatment for acne. We found that 43.96% of patients with persistent adult acne underwent no treatment with antibiotics, isotretinoin, or topical retinoids in adolescence. Patients who did not receive any of these treatments came only for single visits to a dermatologist, did not comply to a recommended therapy, or used only cosmetics or beauty procedures. We found that 80.22% of patients with persistent adult acne never used topical retinoids during adolescence and did not receive maintenance therapy, which may be attributed to the fact that there were no strict recommendations regarding retinoid treatment when these patients were adolescents or young adults. Published data indicate that retinoid use for acne treatment is not common. ¹⁸ Conversely, among patients older than 25 years with late-onset adult acne, there was only 1 patient (ie, < 1%) who had never received any oral antibiotic or isotretinoin treatment or therapy with topical retinoids. The reason for the lack of medical treatment is unknown. Only 25.27% of patients were not treated with topical retinoids, and 35.16% completed at least 2 courses of treatment. The use of topical retinoids for the treatment of persistent and late-onset adult acne may be the result of the spread of knowledge among dermatologists acquired over the last 25 years.

Acne Scarring
The worst complication of acne is scarring. Scars develop for the duration of the disease, during both adolescent and adult acne. In the group with persistent adult acne, scarring was found in 53.85% of patients. Scar formation has been previously reported as a common complication of acne. ¹⁹ The effects of skin lesions that remain after acne are not only limited to impaired cosmetic appearance; they also negatively affect mental health and impair quality of life. ²⁰ The aim of our study was to analyze types of treatment for adolescent acne in patients who later had persistent adult acne. Postacne scars observed later are objective evidence of the severity of disease. We found that using oral antibiotics did not diminish the number of scars among persistent adult acne patients in adulthood. In contrast, isotretinoin or topical retinoid treatment during adolescence decreased the risk for scars occurring during adulthood. In our opinion, these findings emphasize the role of this type of treatment among adolescents or young adults. The decrease of scar formation in adult acne due to retinoid treatment in adolescence indirectly justifies the role of maintenance therapy with topical retinoids. ^21,22

In the last 20 years, the incidence of acne lesions in adults has markedly increased. ¹ Acne affects adults (individuals older than 25 years) and is no longer a condition limited to adolescents and young adults (individuals younger than 25 years). According to Dreno et al, ² the accepted age threshold for the onset of adult acne is 25 years. ^1-3 In 2013, the term adult acne was defined. ² Among patients with adult acne, there are 2 subtypes: (1) persistent adult acne, which is a continuation or recurrence of adolescent acne, affecting approximately 80% of patients, and (2) late-onset acne, affecting approximately 20% of patients. ⁴

Clinical symptoms of adult acne and available treatment modalities have been explored in the literature. Daily clinical experience shows that additional difficulties involved in the management of adult acne patients are related mainly to a high therapeutic failure rate in acne patients older than 25 years. ⁵ Persistent adult acne seems to be noteworthy because it causes long-term symptoms, and patients experience uncontrollable recurrences.

It is believed that adult acne often is resistant to treatment. ² Adult skin is more sensitive to topical agents, leading to more irritation by medications intended for external use and cosmetics. ⁶ Scars in these patients are a frequent and undesirable consequence. ³

Effective treatment of acne encompasses oral antibiotics, topical and systemic retinoids, and oral contraceptive pills (OCPs). For years, oral subantimicrobial doses of cyclines have been recommended for acne treatment. Topical and oral retinoids have been successfully used for more than 30 years as important therapeutic options. ⁷ More recent evidence-based guidelines for acne issued by the American Academy of Dermatology ⁸ and the European Dermatology Forum ⁹ also show that retinoids play an important role in acne therapy. Their anti-inflammatory activity acts against comedones and their precursors (microcomedones). Successful antiacne therapy not only achieves a smooth face without comedones but also minimizes scar formation, postinflammatory discoloration, and long-lasting postinflammatory erythema. ¹⁰ Oral contraceptives have a mainly antiseborrheic effect. ¹¹

Our study sought to analyze the potential influence of therapy during adolescent acne on patients who later developed adult acne. Particular attention was given to the use of oral antibiotics, isotretinoin, and topical retinoids for adolescent acne and their potential role in diminishing scar formation in adult acne.

Materials and Methods

Patient Demographics and Selection
A population-based study of Polish patients with adult acne was conducted. Patients were included in the study group on a consecutive basis from among those who visited our outpatient dermatology center from May 2015 to January 2016. A total of 111 patients (101 women [90.99%] and 10 men [9.01%]) were examined. The study group comprised patients aged 25 years and older who were treated for adult acne (20 patients [18.02%] were aged 25–29 years, 61 [54.95%] were aged 30–39 years, and 30 [27.02%] were 40 years or older).

The following inclusion criteria were used: observation period of at least 6 months in our dermatologic center for patients diagnosed with adult acne, at least 2 dermatologic visits for adult acne prior to the study, written informed consent for study participation and data processing (the aim of the study was explained to each participant by a dermatologist), and age 25 years or older. Exclusion criteria included those who were younger than 25 years, those who had only 1 dermatologic visit at our dermatology center, and those who were unwilling to participate or did not provide written informed consent. Our study was conducted according to Good Clinical Practice.

Data Collection
To obtain data with the highest degree of reliability, 3 sources of information were used: (1) a detailed medical interview conducted by one experienced dermatologist (E.C.) at our dermatology center at the first visit in all study participants, (2) a clinical examination that yielded results necessary for the assessment of scars using a method outlined by Jacob et al, ¹² and (3) information included in available medical records. These data were then statistically analyzed.

Statistical Analysis
The results were presented as frequency plots, and a Fisher exact test was conducted to obtain a statistical comparison of the distributions of analyzed data. Unless otherwise indicated, 5% was adopted as the significance level. The statistical analysis was performed using Stata 14 software (StataCorp LLC, College Station, Texas).

Results

Incidence of Different Forms of Adult Acne
To analyze the onset of acne, patients were categorized into 1 of 2 groups: those with persistent adult acne (81.98%) and those with late-onset adult acne (ie, developed after 25 years of age)(18.02%).

Age at Initiation of Dermatologic Treatment
Of the patients with persistent adult acne, 31.87% first visited a dermatologist the same year that the first acne lesions appeared, 36.26% postponed the first visit by at least 5 years (Figure 1), and 23.08% started treatment at least 10 years after acne first appeared. Among patients with persistent adult acne, 76.92% began dermatologic treatment before 25 years of age, and 23.08% began treatment after 25 years of age. Of the latter, 28.57% did not start therapy until they were older than 35 years.

Severity of Adolescent Acne
In the persistent adult acne group, the severity of adolescent acne was assessed during the medical interview as well as detailed histories in medical records. The activity of acne was evaluated at 2-year intervals with the use of a 10-point scale: 1 to 3 points indicated mild acne (7.69% of patients), 4 to 6 points indicated moderate acne (24.18%), and 7 to 10 points indicated severe acne (68.13%).

Treatment of Persistent Acne in Adolescence
Treatment was comprised of oral therapy with antibiotics, isotretinoin, and/or application of topical retinoids (sometimes supported with OCPs). Monotherapy was the standard of treatment more than 25 years ago when patients with persistent adult acne were treated as adolescents or young adults. As many as 43.96% of patients with persistent adult acne did not receive any of these therapies before 25 years of age; rather, they used antiacne cosmetics or beauty procedures. Furthermore, 50.55% of patients were treated with oral antibiotics (Figure 2). Topical retinoids were used in 19.78% of patients and isotretinoin was used in 16.48%. Incidentally, OCPs were given to 26.5%. In the course of adolescent acne, 31.87% of patients received 2 to 4 courses of treatment with either antibiotics or retinoids (oral or topical), and 5.49% were treated with 5 or more courses of treatment (Figure 3). The analysis of each treatment revealed that only 1 patient received 4 courses of isotretinoin. Five courses of oral antibiotics were given in 1 patient, and 3 courses of topical retinoids were given in the same patient.

Topical Retinoids
In an analysis of the number of treatments with topical retinoids completed by patients with persistent adult acne, it was established that 80.22% of patients never used topical retinoids for acne during adolescence. Additionally, 12.08% of these patients completed 1 course of treatment, and 7.69% completed 2 to 4 treatments. However, after 25 years of age, only 25.27% of the patients with persistent adult acne were not treated with topical retinoids, and 35.16% completed more than 2 courses of treatment.

Duration of Treatment
Because adult acne is a chronic disease, the mean number of years that patients received treatment over the disease course was analyzed. In the case of persistent adult acne, the mean duration of treatment, including therapy received during adolescence, was more than 13 years. At the time of the study, more than 30% of patients had been undergoing treatment of adult acne for more than 20 years. Scars— The proportion of patients with persistent adult acne who experienced scarring was evaluated. In the persistent adult acne group, scars were identified in 53.85% of patients. Scars appeared only during adolescence in 26.37% of patients with persistent adult acne, scars appeared only after 25 years of age in 21.97% of patients, and scars appeared in adolescence as well as adulthood in 30.77% of patients.

In an analysis of patients with persistent adult acne who experienced scarring after 25 years of age, the proportion of patients with untreated adolescent acne and those who were treated with antibiotics only was not significantly different (60% vs 64%; P = .478)(Table). The inclusion of topical retinoids into treatment decreased the proportion of scars (isotretinoin: 20%, P = .009; topical retinoids: 38.89%, P = .114).

Comment

Persistent Adult Acne
Patients with symptoms of persistent adult acne represented 81.98% of the study population, which was similar to a 1999 study by Goulden et al, ¹ a 2001 study by Shaw and White, ¹³ and a 2009 report by Schmidt et al. ¹⁴ Of these patients with persistent adult acne, 23.08% initiated therapy after 25 years of age, and 23.08% started treatment at least 10 years after acne lesions first appeared. However, it is noteworthy that 68.13% of all patients with persistent adult acne assessed their disease as severe.

Treatment Modalities for Adult Acne
Over the last 5 years, some researchers have attempted to make recommendations for the treatment of adult acne based on standards adopted for the treatment of adolescent acne. ^2,9,15 First-line treatment of patients with adult comedonal acne is topical retinoids. ⁹ The recommended treatment of mild to moderate adult inflammatory acne involves topical drugs, including retinoids, azelaic acid, or benzoyl peroxide, or oral medications, including antibiotics, OCPs, or antiandrogens. In severe inflammatory acne, the recommended treatment involves oral isotretinoin or combined therapies; the latter seems to be the most effective. ¹⁶ Furthermore, this therapy has been adjusted to the patient’s current clinical condition; general individual sensitivity of the skin to irritation and the risk for irritant activity of topical medications; and life situation, such as planned pregnancies and intended use of OCPs due to the risk for teratogenic effects of drugs. ¹⁷

To assess available treatment modalities, oral therapy with antibiotics or isotretinoin as well as topical retinoids were selected for our analysis. It is difficult to determine an exclusive impact of OCPs as acne treatment; according to our study, many female patients use hormone therapy for other medical conditions or contraception, and only a small proportion of these patients are prescribed hormone treatment for acne. We found that 43.96% of patients with persistent adult acne underwent no treatment with antibiotics, isotretinoin, or topical retinoids in adolescence. Patients who did not receive any of these treatments came only for single visits to a dermatologist, did not comply to a recommended therapy, or used only cosmetics or beauty procedures. We found that 80.22% of patients with persistent adult acne never used topical retinoids during adolescence and did not receive maintenance therapy, which may be attributed to the fact that there were no strict recommendations regarding retinoid treatment when these patients were adolescents or young adults. Published data indicate that retinoid use for acne treatment is not common. ¹⁸ Conversely, among patients older than 25 years with late-onset adult acne, there was only 1 patient (ie, < 1%) who had never received any oral antibiotic or isotretinoin treatment or therapy with topical retinoids. The reason for the lack of medical treatment is unknown. Only 25.27% of patients were not treated with topical retinoids, and 35.16% completed at least 2 courses of treatment. The use of topical retinoids for the treatment of persistent and late-onset adult acne may be the result of the spread of knowledge among dermatologists acquired over the last 25 years.

Acne Scarring
The worst complication of acne is scarring. Scars develop for the duration of the disease, during both adolescent and adult acne. In the group with persistent adult acne, scarring was found in 53.85% of patients. Scar formation has been previously reported as a common complication of acne. ¹⁹ The effects of skin lesions that remain after acne are not only limited to impaired cosmetic appearance; they also negatively affect mental health and impair quality of life. ²⁰ The aim of our study was to analyze types of treatment for adolescent acne in patients who later had persistent adult acne. Postacne scars observed later are objective evidence of the severity of disease. We found that using oral antibiotics did not diminish the number of scars among persistent adult acne patients in adulthood. In contrast, isotretinoin or topical retinoid treatment during adolescence decreased the risk for scars occurring during adulthood. In our opinion, these findings emphasize the role of this type of treatment among adolescents or young adults. The decrease of scar formation in adult acne due to retinoid treatment in adolescence indirectly justifies the role of maintenance therapy with topical retinoids. ^21,22

Inflammation is a backdrop to the commonly cited elements of the pathophysiology of acne: Propionibacterium acnes proliferation, increased sebum production with an increase in circulating androgens, and faulty keratinization.^1,2 In fact, research shows that the initiating lesion of acne vulgaris—the microcomedone—is, in essence, an inflammatory lesion.³ This realization has clearly influenced the approach to acne treatment but has not yielded a bevy of new treatments.

A better understanding of acne pathophysiology and the role of inflammation has, however, yielded a better understanding of how existing therapies treat the disease and have led to more comprehensive treatment strategies that are multitargeted. Nonetheless, topical and oral antibiotics remain mainstays of acne therapy, along with topical retinoids and benzoyl peroxide. Current guidelines of care for acne emphasize strategies that reduce dependence on antibiotics and minimize the risk for resistance.⁴ The therapeutic landscape might at last be shifting, with new chemical entities for acne and several novel formulations in development.

Sarecycline: A Novel Tetracycline

Tetracycline antibiotics have been used to manage acne since the 1950s, but their method of action in the disease has not been fully elucidated.⁵ In addition to antibiotic effects, tetracyclines have been shown to confer anti-inflammatory properties and other biologic effects.^6,7

First-generation tetracycline is broad spectrum. As such, it is associated with increased potential for antibiotic resistance and greater impact on gastrointestinal health. The novel compound sarecycline is a tetracycline with a narrower spectrum of activity compared to other tetracyclines and with reduced activity against enteric gram-negative bacteria⁸ (Figure 1). Sarecycline recently was approved by the US Food and Drug Administration (FDA) in a once-daily oral formulation for the treatment of inflammatory lesions of nonnodular moderate to severe acne vulgaris in patients 9 years and older. Sarecycline is dosed at 1.5 mg/kg daily. The FDA approval marks the first new antibiotic approved for acne in 4 decades.

Sarecycline also was assessed in the 2 trials for efficacy in the treatment of back and chest acne; in the active treatment group, IGA success was achieved by 29.6% and 36.6%, respectively, compared to 19.6% and 21.6%, respectively, of controls.⁹

Tazarotene Foam in Focus

Topical tazarotene is commercially available in cream, gel, and foam formulations. Tazarotene foam 0.1% was FDA approved in 2012 for the treatment of acne vulgaris in patients 12 years and older. However, the product was recently relaunched to the market and therefore warrants discussion.

Similar to other retinoids, topical tazarotene has been associated with the potential for application-site irritation. This aqueous foam formulation of tazarotene was designed for ease of application and to attempt to impart moisturizing effects to offset potential irritation. It contains noncomedogenic light mineral oil, which is an emollient. The foam spreads easily, including on hair-bearing skin, with demonstrated penetration of the active drug into the epidermis and dermis. Nonetheless, compared to the gel formulation of tazarotene, the foam formulation was associated with reduced systemic exposure.¹⁰

The tazarotene foam formulation does not contain alcohol, fragrance, propylene glycol, or parabens. Clinical trial participants, blinded to whether they were on active treatment or vehicle foam, consistently rated the foam formulation favorably for ease of application and spreadability, lack of stickiness or residue, and moisturizing effect. The foam vehicle is suggested to increase compliance and satisfaction in some patients.¹¹The efficacy and tolerability of tazarotene foam 0.1% was investigated in 2 randomized, double-blind, vehicle-controlled, parallel-group studies in the United States and Canada.¹² The studies involved participants aged 2 to 45 years who were randomized to receive treatment with either tazarotene foam 0.1% or vehicle foam once daily for 12 weeks (N=1486). Lesion counts, investigator static global assessment, and subject global assessment were evaluated at baseline and at weeks 2, 4, 8, and 12. At week 12, mean reduction from baseline in noninflammatory lesions was 55.9% for active treatment, mean reduction in inflammatory lesions was 56.1%, and mean total lesion reduction was 56% compared to mean reductions of 37.7%, 45.3%, and 40.8%, respectively, for vehicle. In all, 28.2% of participants achieved treatment success with active treatment compared to 14.7% of controls. There was a greater proportion of active-treatment participants with investigator static global assessment scores of 0 or 1 compared to vehicle. The only adverse events reported by more than 5% of participants in the active-treatment groups in both studies were application-site skin irritation and dryness.¹²

Topical Minocycline

Systemic minocycline is the most commonly prescribed oral antibiotic for acne management.¹³ Despite its widespread use, it is not without potential safety concerns. Minocycline is distinct among tetracyclines for posing a small risk for systemic lupus erythematosus and autoimmune TEAE.Gastrointestinal side effects and bluish discoloration also are reported.¹⁴ Topical application of minocycline for acne would optimize the therapeutic effect while reducing systemic effects. FMX101 4%, an investigational minocycline foam, is being studied for the treatment of moderate to severe acne.

In a pharmacokinetic study, minocycline exposure was 730- to 765-times lower with foam application vs oral minocycline.¹⁵ No evidence of minocycline accumulation was identified over the 21 days of application of minocycline foam 4%. Minocycline foam 4% appeared to be safe and well tolerated, without serious TEAEs, treatment-related TEAEs, or TEAEs that led to treatment discontinuation.¹⁵

In 2 identical phase 3 studies in which 961 participants were randomized (2:1) to once-daily minocycline foam 4% or foam vehicle for 12 weeks, participants in the active-treatment group demonstrated a significantly greater reduction in both inflammatory and noninflammatory lesions in both studies (both P<.05) and a greater rate of treatment success (≥2 point reduction in IGA and score of 0 [clear] or 1 [almost clear]) in 1 study. Treatment was generally safe and well tolerated, with skin-related adverse events reported in fewer than 1% of participants receiving active treatment.¹⁶

In an open-label safety extension study that enrolled 657 patients, treatment with FMX101 continued for as long as 40 weeks.¹⁷ In total, 291 participants completed 52 weeks of therapy. Rates and types of reported TEAEs in the open-label extension phase were similar to those seen in the phase 3 trials. Application-site TEAEs occurred in fewer than 2% of participants. Participants reported a high level of treatment satisfaction at week 52.¹⁷

In a more recent phase 3 study, 1507 participants were randomized (1:1) to once-daily minocycline foam 4% or foam vehicle for 12 weeks to further evaluate the efficacy and safety of FMX101 4% for moderate to severe acne vulgaris.¹⁸ The study met both primary end points: absolute change from baseline in the inflammatory lesion count (−16.93 vs −13.40; P<.0001) and the noninflammatory lesion count (−18.80 vs −15.89; P<.05), as well as percentage of participants with IGA treatment success at week 12 (30.80% vs 19.63%; P<.0001). The percentage reduction in the inflammatory lesion count was statistically significantly greater for minocycline foam 4% compared to vehicle as early as week 3 (P<.0001). The safety profile was found to be consistent with the 2 earlier phase 3 studies.¹⁸

Topical Minocycline in Rosacea

A similar foam formulation of minocycline (1.5% concentration) has shown benefit in 2 identical phase 3 studies.¹⁹ A total of 1522 participants were enrolled in 2 phase 3, randomized, multicenter, double-blind, vehicle-controlled, 2-arm studies in participants 18 years and older with moderate to severe papulopustular rosacea. Participants were randomized (2:1) to either minocycline foam 1.5% or vehicle once daily to the face for 12 weeks.¹⁹

Treatment was associated with a statistically significant reduction in counts of inflammatory lesions of rosacea (Study FX2016-11: −17.57 vs −15.65 [P=.003]; Study FX2016-12: −18.54 vs −14.88 [P<.0001]) and a significantly higher rate of IGA treatment success compared to vehicle (Study FX2016-11: 52.1% vs 43.0% [P=.027]; Study FX2016-12: 49.1% vs 39.0% [P=.008]), highlighting the anti-inflammatory action of the topically applied agent.¹⁹

The most common TEAE for both studies was upper respiratory tract infection; there were no serious TEAEs. Overall, 9 participants across both studies discontinued because of a TEAE (foam, 7 participants; vehicle, 2 participants).¹⁹

Clascoterone: First-in-Class Topical

Clascoterone cream 1% is a new chemical entity under investigation for the treatment of moderate to severe acne in patients 9 years and older. Clascoterone targets androgen receptors in the skin to block the effects of circulating endogenous androgens; chemically, it shares a 4-ring backbone identical to dihydrotestosterone and spironolactone (Figure 2). Clascoterone competes with dihydrotestosterone for binding to the androgen receptor to limit or block transcription of androgen-responsive genes and modify specific gene expression.²⁰

Androgens are known to promote both sebum production and inflammatory responses within the follicle, contributing to the cycle of acne.²¹ Antiandrogen therapy would, therefore, inhibit excess sebum production and directly reduce the presence of certain inflammatory mediators in skin. This effect is expected to lead to reduced follicular plugging and a reduction in growth of P acnes and its inflammatory by-products.

Direct and indirect hormonal modulation have been successfully employed to manage acne in women; however, such therapies have not been considered first-line interventions for the disease.²² Although systemic antiandrogens and hormonal modulation are effective for certain women with acne, there may be concerns about systemic exposure²³; no hormone-modulating agent has been adopted for use in men with acne.

As an androgen inhibitor, clascoterone is thought to displace androgen hormones from androgen receptors located at the sebaceous gland and hair follicle, thus inhibiting the cycle of physiologic events that leads to acne formation. Clascoterone is applied topically and acts locally on androgen receptors in the skin, with no systemic exposure seen. In phase 2 trials, clascoterone was found to be safe and effective with no systemic exposure and was suggested to have better tolerability than topical tretinoin.

Preliminary individual study analysis of data from 2 phase 3 trials showed that topical clascoterone met its primary end points, achieving statistically significantly greater rates of IGA treatment success (≥2 point reduction in IGA and score of 0 [clear] or 1 [almost clear]) at week 12 (P<.0001).²⁴ Rates of treatment success for actively treated participants were 16.1% and 18.7%, respectively, compared to 7% and 4.7%, respectively, for vehicle. The study population included both males and nonpregnant females 9 years and older who had a baseline IGA score of 3 (moderate) or 4 (severe). At baseline, participants had a mix of inflammatory lesions (≥30, to a maximum of 75) and noninflammatory lesions (≥30, to a maximum of 100).²⁴

Intention-to-treat analysis at week 12 showed a mean total lesion reduction from baseline for active treatment of 37.1% and 37.7%, respectively, compared to 28.5% and 22.2%, respectively, for controls.²⁴ Mean reductions from baseline in noninflammatory lesions for active treatment were 30.7% and 29.3%, respectively, compared to 21.9% and 15.8%, respectively, for controls. Mean reductions from baseline in inflammatory lesions for active treatment were 44.8% and 47%, respectively, compared to 36.6% and 29.8%, respectively, for controls. Similarly low rates of TEAEs were reported in active and placebo groups in both studies. No TEAE suggested systemic antiandrogen exposure.²⁴

Advancements in Cannabinoids

Advancements in pharmaceutical development of cannabinoid compounds have largely coincided with the controversial national movement to legalize medical marijuana and decriminalize recreational marijuana use. Despite the temporal connection, the 2 topics are entirely distinct. Importantly, pharmaceutical development is largely focused on the effects of cannabidiol (CBD), which is 1 of approximately 113 cannabinoids identified from Cannabis sativa. Cannabidiol is not tetrahydrocannabinol, or THC, the compound responsible for marijuana’s psychoactive effects and addictive properties; CBD does not have any psychoactive effects and is not addictive (Figure 3).²⁵

A CBD oral solution agent recently gained FDA approval for seizures associated with Lennox-Gastaut syndrome or Dravet syndrome in patients 2 years and older; it is estimated that more than 180 trials of CBD are ongoing in the United States for various indications.²⁶ A notable question in the development of CBD-based therapies is: What is the role of natural plant-derived CBD compared to a pure synthetic form of CBD? The latter is akin to a pharmaceutical process in which a single molecule is developed as the active drug.²⁷ Although the potency and composition of plant-derived CBD can vary with crop conditions, plant strains, and the extraction process, a synthetic molecule would allow for consistency in safety, potency, and pharmacokinetic properties, as well as efficacy, as a consequence.²⁶

There are intriguing data to suggest a potential use for topical CBD in the management of skin diseases, including acne vulgaris. Researchers have, for at least a decade, been investigating the role of the endocannabinoid system, which has physiologic regulatory functions in proliferation, differentiation, apoptosis and cytokine, mediator, and hormone production of various cell types in skin, hair follicles, and sebaceous glands.²⁸ Cannabidiol has been shown to suppress proliferation of sebocytes through activation of transient receptor potential vanilloid 4 ion channels and to have anti-inflammatory effects on sebocytes.²⁹ It has been shown to inhibit human keratinocyte proliferation through a non-CB1/CB2 mechanism³⁰ and to possess potent antimicrobial activity against gram-positive bacteria such as P acnes.³¹

Given these effects on sebocytes, modulation of keratinocyte proliferation, and anti-inflammatory and antibacterial effects, CBD could prove beneficial in the management of acne vulgaris. A new synthetic CBD topical formulation, BTX 1503, is under investigation for the treatment of acne vulgaris.

Early clinical data confirm both the anti-inflammatory effects of topical BTX 1503 as well as its effects on noninflammatory lesions, with 4-week reductions in inflammatory lesion counts similar to what are reported in clinical trials for leading FDA-approved topical therapies in the same time frame.

The phase 1b trial was a 4-week, open-label study in participants with moderate to severe acne vulgaris.³² The primary end point was safety, as demonstrated by the incidence of TEAE, laboratory monitoring, and assessment of cutaneous tolerability. Exploratory end points included changes in inflammatory and noninflammatory lesion counts and IGA score. A total of 21 participants aged 18 to 65 years with moderate to severe acne vulgaris were enrolled. BTX 1503 was applied topically twice daily. At baseline, eligible participants had 20 to 50 inflammatory lesions and 20 to 100 noninflammatory acne lesions on the face, an IGA of 3 (moderate) or 4 (severe), and 3 or fewer nodular or cystic lesions (>5 mm in diameter). No serious or severe TEAEs were reported; no participants withdrew due to a TEAE. Slight erythema, slight scaling, slight dryness, and slight burning and stinging were reported; there were no reports of irritant or allergic contact dermatitis. Only 1 TEAE was thought to be possibly related to treatment: mild pain at the application site.³²

In addition to presenting a potential new chemical entity for the topical treatment of acne, the novel topical vehicle formulation of BTX 1503 represents an innovative approach to drug delivery. The formulation utilizes proprietary technology to deliver high doses of drug into the skin without controversial penetration enhancers, preservatives, or other potential irritating additives. Instead, volatile excipients are used that evaporate upon application to the skin, leaving a so-called superconcentrated secondary formulation on the skin. The concentration gradient effect then drives the concentrated drug into skin. Although the formulation efficiently delivers active drug into the skin and its appendages, systemic exposure has been reported to be very low. A phase 2 randomized, double-blind, vehicle-controlled trial ongoing in the United States and Australia in 360 patients with moderate to severe acne vulgaris will provide key data to confirm the efficacy and safety of BTX 1503 (ClinicalTrials.gov Identifier NCT03573518).

Conclusion

Drug development continues to focus on the challenge of treating acne effectively and safely. Vehicle innovations are optimizing existing active drugs and creating opportunities to deliver new compounds to the skin. The approval of sarecycline as the first new chemical entity approved for acne in several years may be followed in coming years by other new actives, including clascoterone and CBD.

Inflammation is a backdrop to the commonly cited elements of the pathophysiology of acne: Propionibacterium acnes proliferation, increased sebum production with an increase in circulating androgens, and faulty keratinization.^1,2 In fact, research shows that the initiating lesion of acne vulgaris—the microcomedone—is, in essence, an inflammatory lesion.³ This realization has clearly influenced the approach to acne treatment but has not yielded a bevy of new treatments.

A better understanding of acne pathophysiology and the role of inflammation has, however, yielded a better understanding of how existing therapies treat the disease and have led to more comprehensive treatment strategies that are multitargeted. Nonetheless, topical and oral antibiotics remain mainstays of acne therapy, along with topical retinoids and benzoyl peroxide. Current guidelines of care for acne emphasize strategies that reduce dependence on antibiotics and minimize the risk for resistance.⁴ The therapeutic landscape might at last be shifting, with new chemical entities for acne and several novel formulations in development.

Sarecycline: A Novel Tetracycline

Tetracycline antibiotics have been used to manage acne since the 1950s, but their method of action in the disease has not been fully elucidated.⁵ In addition to antibiotic effects, tetracyclines have been shown to confer anti-inflammatory properties and other biologic effects.^6,7

First-generation tetracycline is broad spectrum. As such, it is associated with increased potential for antibiotic resistance and greater impact on gastrointestinal health. The novel compound sarecycline is a tetracycline with a narrower spectrum of activity compared to other tetracyclines and with reduced activity against enteric gram-negative bacteria⁸ (Figure 1). Sarecycline recently was approved by the US Food and Drug Administration (FDA) in a once-daily oral formulation for the treatment of inflammatory lesions of nonnodular moderate to severe acne vulgaris in patients 9 years and older. Sarecycline is dosed at 1.5 mg/kg daily. The FDA approval marks the first new antibiotic approved for acne in 4 decades.

Sarecycline also was assessed in the 2 trials for efficacy in the treatment of back and chest acne; in the active treatment group, IGA success was achieved by 29.6% and 36.6%, respectively, compared to 19.6% and 21.6%, respectively, of controls.⁹

Tazarotene Foam in Focus

Topical tazarotene is commercially available in cream, gel, and foam formulations. Tazarotene foam 0.1% was FDA approved in 2012 for the treatment of acne vulgaris in patients 12 years and older. However, the product was recently relaunched to the market and therefore warrants discussion.

Similar to other retinoids, topical tazarotene has been associated with the potential for application-site irritation. This aqueous foam formulation of tazarotene was designed for ease of application and to attempt to impart moisturizing effects to offset potential irritation. It contains noncomedogenic light mineral oil, which is an emollient. The foam spreads easily, including on hair-bearing skin, with demonstrated penetration of the active drug into the epidermis and dermis. Nonetheless, compared to the gel formulation of tazarotene, the foam formulation was associated with reduced systemic exposure.¹⁰

The tazarotene foam formulation does not contain alcohol, fragrance, propylene glycol, or parabens. Clinical trial participants, blinded to whether they were on active treatment or vehicle foam, consistently rated the foam formulation favorably for ease of application and spreadability, lack of stickiness or residue, and moisturizing effect. The foam vehicle is suggested to increase compliance and satisfaction in some patients.¹¹The efficacy and tolerability of tazarotene foam 0.1% was investigated in 2 randomized, double-blind, vehicle-controlled, parallel-group studies in the United States and Canada.¹² The studies involved participants aged 2 to 45 years who were randomized to receive treatment with either tazarotene foam 0.1% or vehicle foam once daily for 12 weeks (N=1486). Lesion counts, investigator static global assessment, and subject global assessment were evaluated at baseline and at weeks 2, 4, 8, and 12. At week 12, mean reduction from baseline in noninflammatory lesions was 55.9% for active treatment, mean reduction in inflammatory lesions was 56.1%, and mean total lesion reduction was 56% compared to mean reductions of 37.7%, 45.3%, and 40.8%, respectively, for vehicle. In all, 28.2% of participants achieved treatment success with active treatment compared to 14.7% of controls. There was a greater proportion of active-treatment participants with investigator static global assessment scores of 0 or 1 compared to vehicle. The only adverse events reported by more than 5% of participants in the active-treatment groups in both studies were application-site skin irritation and dryness.¹²

Topical Minocycline

Systemic minocycline is the most commonly prescribed oral antibiotic for acne management.¹³ Despite its widespread use, it is not without potential safety concerns. Minocycline is distinct among tetracyclines for posing a small risk for systemic lupus erythematosus and autoimmune TEAE.Gastrointestinal side effects and bluish discoloration also are reported.¹⁴ Topical application of minocycline for acne would optimize the therapeutic effect while reducing systemic effects. FMX101 4%, an investigational minocycline foam, is being studied for the treatment of moderate to severe acne.

In a pharmacokinetic study, minocycline exposure was 730- to 765-times lower with foam application vs oral minocycline.¹⁵ No evidence of minocycline accumulation was identified over the 21 days of application of minocycline foam 4%. Minocycline foam 4% appeared to be safe and well tolerated, without serious TEAEs, treatment-related TEAEs, or TEAEs that led to treatment discontinuation.¹⁵

In 2 identical phase 3 studies in which 961 participants were randomized (2:1) to once-daily minocycline foam 4% or foam vehicle for 12 weeks, participants in the active-treatment group demonstrated a significantly greater reduction in both inflammatory and noninflammatory lesions in both studies (both P<.05) and a greater rate of treatment success (≥2 point reduction in IGA and score of 0 [clear] or 1 [almost clear]) in 1 study. Treatment was generally safe and well tolerated, with skin-related adverse events reported in fewer than 1% of participants receiving active treatment.¹⁶

In an open-label safety extension study that enrolled 657 patients, treatment with FMX101 continued for as long as 40 weeks.¹⁷ In total, 291 participants completed 52 weeks of therapy. Rates and types of reported TEAEs in the open-label extension phase were similar to those seen in the phase 3 trials. Application-site TEAEs occurred in fewer than 2% of participants. Participants reported a high level of treatment satisfaction at week 52.¹⁷

In a more recent phase 3 study, 1507 participants were randomized (1:1) to once-daily minocycline foam 4% or foam vehicle for 12 weeks to further evaluate the efficacy and safety of FMX101 4% for moderate to severe acne vulgaris.¹⁸ The study met both primary end points: absolute change from baseline in the inflammatory lesion count (−16.93 vs −13.40; P<.0001) and the noninflammatory lesion count (−18.80 vs −15.89; P<.05), as well as percentage of participants with IGA treatment success at week 12 (30.80% vs 19.63%; P<.0001). The percentage reduction in the inflammatory lesion count was statistically significantly greater for minocycline foam 4% compared to vehicle as early as week 3 (P<.0001). The safety profile was found to be consistent with the 2 earlier phase 3 studies.¹⁸

Topical Minocycline in Rosacea

A similar foam formulation of minocycline (1.5% concentration) has shown benefit in 2 identical phase 3 studies.¹⁹ A total of 1522 participants were enrolled in 2 phase 3, randomized, multicenter, double-blind, vehicle-controlled, 2-arm studies in participants 18 years and older with moderate to severe papulopustular rosacea. Participants were randomized (2:1) to either minocycline foam 1.5% or vehicle once daily to the face for 12 weeks.¹⁹

Treatment was associated with a statistically significant reduction in counts of inflammatory lesions of rosacea (Study FX2016-11: −17.57 vs −15.65 [P=.003]; Study FX2016-12: −18.54 vs −14.88 [P<.0001]) and a significantly higher rate of IGA treatment success compared to vehicle (Study FX2016-11: 52.1% vs 43.0% [P=.027]; Study FX2016-12: 49.1% vs 39.0% [P=.008]), highlighting the anti-inflammatory action of the topically applied agent.¹⁹

The most common TEAE for both studies was upper respiratory tract infection; there were no serious TEAEs. Overall, 9 participants across both studies discontinued because of a TEAE (foam, 7 participants; vehicle, 2 participants).¹⁹

Clascoterone: First-in-Class Topical

Clascoterone cream 1% is a new chemical entity under investigation for the treatment of moderate to severe acne in patients 9 years and older. Clascoterone targets androgen receptors in the skin to block the effects of circulating endogenous androgens; chemically, it shares a 4-ring backbone identical to dihydrotestosterone and spironolactone (Figure 2). Clascoterone competes with dihydrotestosterone for binding to the androgen receptor to limit or block transcription of androgen-responsive genes and modify specific gene expression.²⁰

Androgens are known to promote both sebum production and inflammatory responses within the follicle, contributing to the cycle of acne.²¹ Antiandrogen therapy would, therefore, inhibit excess sebum production and directly reduce the presence of certain inflammatory mediators in skin. This effect is expected to lead to reduced follicular plugging and a reduction in growth of P acnes and its inflammatory by-products.

Direct and indirect hormonal modulation have been successfully employed to manage acne in women; however, such therapies have not been considered first-line interventions for the disease.²² Although systemic antiandrogens and hormonal modulation are effective for certain women with acne, there may be concerns about systemic exposure²³; no hormone-modulating agent has been adopted for use in men with acne.

As an androgen inhibitor, clascoterone is thought to displace androgen hormones from androgen receptors located at the sebaceous gland and hair follicle, thus inhibiting the cycle of physiologic events that leads to acne formation. Clascoterone is applied topically and acts locally on androgen receptors in the skin, with no systemic exposure seen. In phase 2 trials, clascoterone was found to be safe and effective with no systemic exposure and was suggested to have better tolerability than topical tretinoin.

Preliminary individual study analysis of data from 2 phase 3 trials showed that topical clascoterone met its primary end points, achieving statistically significantly greater rates of IGA treatment success (≥2 point reduction in IGA and score of 0 [clear] or 1 [almost clear]) at week 12 (P<.0001).²⁴ Rates of treatment success for actively treated participants were 16.1% and 18.7%, respectively, compared to 7% and 4.7%, respectively, for vehicle. The study population included both males and nonpregnant females 9 years and older who had a baseline IGA score of 3 (moderate) or 4 (severe). At baseline, participants had a mix of inflammatory lesions (≥30, to a maximum of 75) and noninflammatory lesions (≥30, to a maximum of 100).²⁴

Intention-to-treat analysis at week 12 showed a mean total lesion reduction from baseline for active treatment of 37.1% and 37.7%, respectively, compared to 28.5% and 22.2%, respectively, for controls.²⁴ Mean reductions from baseline in noninflammatory lesions for active treatment were 30.7% and 29.3%, respectively, compared to 21.9% and 15.8%, respectively, for controls. Mean reductions from baseline in inflammatory lesions for active treatment were 44.8% and 47%, respectively, compared to 36.6% and 29.8%, respectively, for controls. Similarly low rates of TEAEs were reported in active and placebo groups in both studies. No TEAE suggested systemic antiandrogen exposure.²⁴

Advancements in Cannabinoids

Advancements in pharmaceutical development of cannabinoid compounds have largely coincided with the controversial national movement to legalize medical marijuana and decriminalize recreational marijuana use. Despite the temporal connection, the 2 topics are entirely distinct. Importantly, pharmaceutical development is largely focused on the effects of cannabidiol (CBD), which is 1 of approximately 113 cannabinoids identified from Cannabis sativa. Cannabidiol is not tetrahydrocannabinol, or THC, the compound responsible for marijuana’s psychoactive effects and addictive properties; CBD does not have any psychoactive effects and is not addictive (Figure 3).²⁵

A CBD oral solution agent recently gained FDA approval for seizures associated with Lennox-Gastaut syndrome or Dravet syndrome in patients 2 years and older; it is estimated that more than 180 trials of CBD are ongoing in the United States for various indications.²⁶ A notable question in the development of CBD-based therapies is: What is the role of natural plant-derived CBD compared to a pure synthetic form of CBD? The latter is akin to a pharmaceutical process in which a single molecule is developed as the active drug.²⁷ Although the potency and composition of plant-derived CBD can vary with crop conditions, plant strains, and the extraction process, a synthetic molecule would allow for consistency in safety, potency, and pharmacokinetic properties, as well as efficacy, as a consequence.²⁶

There are intriguing data to suggest a potential use for topical CBD in the management of skin diseases, including acne vulgaris. Researchers have, for at least a decade, been investigating the role of the endocannabinoid system, which has physiologic regulatory functions in proliferation, differentiation, apoptosis and cytokine, mediator, and hormone production of various cell types in skin, hair follicles, and sebaceous glands.²⁸ Cannabidiol has been shown to suppress proliferation of sebocytes through activation of transient receptor potential vanilloid 4 ion channels and to have anti-inflammatory effects on sebocytes.²⁹ It has been shown to inhibit human keratinocyte proliferation through a non-CB1/CB2 mechanism³⁰ and to possess potent antimicrobial activity against gram-positive bacteria such as P acnes.³¹

Given these effects on sebocytes, modulation of keratinocyte proliferation, and anti-inflammatory and antibacterial effects, CBD could prove beneficial in the management of acne vulgaris. A new synthetic CBD topical formulation, BTX 1503, is under investigation for the treatment of acne vulgaris.

Early clinical data confirm both the anti-inflammatory effects of topical BTX 1503 as well as its effects on noninflammatory lesions, with 4-week reductions in inflammatory lesion counts similar to what are reported in clinical trials for leading FDA-approved topical therapies in the same time frame.

The phase 1b trial was a 4-week, open-label study in participants with moderate to severe acne vulgaris.³² The primary end point was safety, as demonstrated by the incidence of TEAE, laboratory monitoring, and assessment of cutaneous tolerability. Exploratory end points included changes in inflammatory and noninflammatory lesion counts and IGA score. A total of 21 participants aged 18 to 65 years with moderate to severe acne vulgaris were enrolled. BTX 1503 was applied topically twice daily. At baseline, eligible participants had 20 to 50 inflammatory lesions and 20 to 100 noninflammatory acne lesions on the face, an IGA of 3 (moderate) or 4 (severe), and 3 or fewer nodular or cystic lesions (>5 mm in diameter). No serious or severe TEAEs were reported; no participants withdrew due to a TEAE. Slight erythema, slight scaling, slight dryness, and slight burning and stinging were reported; there were no reports of irritant or allergic contact dermatitis. Only 1 TEAE was thought to be possibly related to treatment: mild pain at the application site.³²

In addition to presenting a potential new chemical entity for the topical treatment of acne, the novel topical vehicle formulation of BTX 1503 represents an innovative approach to drug delivery. The formulation utilizes proprietary technology to deliver high doses of drug into the skin without controversial penetration enhancers, preservatives, or other potential irritating additives. Instead, volatile excipients are used that evaporate upon application to the skin, leaving a so-called superconcentrated secondary formulation on the skin. The concentration gradient effect then drives the concentrated drug into skin. Although the formulation efficiently delivers active drug into the skin and its appendages, systemic exposure has been reported to be very low. A phase 2 randomized, double-blind, vehicle-controlled trial ongoing in the United States and Australia in 360 patients with moderate to severe acne vulgaris will provide key data to confirm the efficacy and safety of BTX 1503 (ClinicalTrials.gov Identifier NCT03573518).

Conclusion

Drug development continues to focus on the challenge of treating acne effectively and safely. Vehicle innovations are optimizing existing active drugs and creating opportunities to deliver new compounds to the skin. The approval of sarecycline as the first new chemical entity approved for acne in several years may be followed in coming years by other new actives, including clascoterone and CBD.

Inflammation is a backdrop to the commonly cited elements of the pathophysiology of acne: Propionibacterium acnes proliferation, increased sebum production with an increase in circulating androgens, and faulty keratinization.^1,2 In fact, research shows that the initiating lesion of acne vulgaris—the microcomedone—is, in essence, an inflammatory lesion.³ This realization has clearly influenced the approach to acne treatment but has not yielded a bevy of new treatments.

A better understanding of acne pathophysiology and the role of inflammation has, however, yielded a better understanding of how existing therapies treat the disease and have led to more comprehensive treatment strategies that are multitargeted. Nonetheless, topical and oral antibiotics remain mainstays of acne therapy, along with topical retinoids and benzoyl peroxide. Current guidelines of care for acne emphasize strategies that reduce dependence on antibiotics and minimize the risk for resistance.⁴ The therapeutic landscape might at last be shifting, with new chemical entities for acne and several novel formulations in development.

Sarecycline: A Novel Tetracycline

Tetracycline antibiotics have been used to manage acne since the 1950s, but their method of action in the disease has not been fully elucidated.⁵ In addition to antibiotic effects, tetracyclines have been shown to confer anti-inflammatory properties and other biologic effects.^6,7

First-generation tetracycline is broad spectrum. As such, it is associated with increased potential for antibiotic resistance and greater impact on gastrointestinal health. The novel compound sarecycline is a tetracycline with a narrower spectrum of activity compared to other tetracyclines and with reduced activity against enteric gram-negative bacteria⁸ (Figure 1). Sarecycline recently was approved by the US Food and Drug Administration (FDA) in a once-daily oral formulation for the treatment of inflammatory lesions of nonnodular moderate to severe acne vulgaris in patients 9 years and older. Sarecycline is dosed at 1.5 mg/kg daily. The FDA approval marks the first new antibiotic approved for acne in 4 decades.

Sarecycline also was assessed in the 2 trials for efficacy in the treatment of back and chest acne; in the active treatment group, IGA success was achieved by 29.6% and 36.6%, respectively, compared to 19.6% and 21.6%, respectively, of controls.⁹

Tazarotene Foam in Focus

Topical tazarotene is commercially available in cream, gel, and foam formulations. Tazarotene foam 0.1% was FDA approved in 2012 for the treatment of acne vulgaris in patients 12 years and older. However, the product was recently relaunched to the market and therefore warrants discussion.

Similar to other retinoids, topical tazarotene has been associated with the potential for application-site irritation. This aqueous foam formulation of tazarotene was designed for ease of application and to attempt to impart moisturizing effects to offset potential irritation. It contains noncomedogenic light mineral oil, which is an emollient. The foam spreads easily, including on hair-bearing skin, with demonstrated penetration of the active drug into the epidermis and dermis. Nonetheless, compared to the gel formulation of tazarotene, the foam formulation was associated with reduced systemic exposure.¹⁰

The tazarotene foam formulation does not contain alcohol, fragrance, propylene glycol, or parabens. Clinical trial participants, blinded to whether they were on active treatment or vehicle foam, consistently rated the foam formulation favorably for ease of application and spreadability, lack of stickiness or residue, and moisturizing effect. The foam vehicle is suggested to increase compliance and satisfaction in some patients.¹¹The efficacy and tolerability of tazarotene foam 0.1% was investigated in 2 randomized, double-blind, vehicle-controlled, parallel-group studies in the United States and Canada.¹² The studies involved participants aged 2 to 45 years who were randomized to receive treatment with either tazarotene foam 0.1% or vehicle foam once daily for 12 weeks (N=1486). Lesion counts, investigator static global assessment, and subject global assessment were evaluated at baseline and at weeks 2, 4, 8, and 12. At week 12, mean reduction from baseline in noninflammatory lesions was 55.9% for active treatment, mean reduction in inflammatory lesions was 56.1%, and mean total lesion reduction was 56% compared to mean reductions of 37.7%, 45.3%, and 40.8%, respectively, for vehicle. In all, 28.2% of participants achieved treatment success with active treatment compared to 14.7% of controls. There was a greater proportion of active-treatment participants with investigator static global assessment scores of 0 or 1 compared to vehicle. The only adverse events reported by more than 5% of participants in the active-treatment groups in both studies were application-site skin irritation and dryness.¹²

Topical Minocycline

Systemic minocycline is the most commonly prescribed oral antibiotic for acne management.¹³ Despite its widespread use, it is not without potential safety concerns. Minocycline is distinct among tetracyclines for posing a small risk for systemic lupus erythematosus and autoimmune TEAE.Gastrointestinal side effects and bluish discoloration also are reported.¹⁴ Topical application of minocycline for acne would optimize the therapeutic effect while reducing systemic effects. FMX101 4%, an investigational minocycline foam, is being studied for the treatment of moderate to severe acne.

In a pharmacokinetic study, minocycline exposure was 730- to 765-times lower with foam application vs oral minocycline.¹⁵ No evidence of minocycline accumulation was identified over the 21 days of application of minocycline foam 4%. Minocycline foam 4% appeared to be safe and well tolerated, without serious TEAEs, treatment-related TEAEs, or TEAEs that led to treatment discontinuation.¹⁵

In 2 identical phase 3 studies in which 961 participants were randomized (2:1) to once-daily minocycline foam 4% or foam vehicle for 12 weeks, participants in the active-treatment group demonstrated a significantly greater reduction in both inflammatory and noninflammatory lesions in both studies (both P<.05) and a greater rate of treatment success (≥2 point reduction in IGA and score of 0 [clear] or 1 [almost clear]) in 1 study. Treatment was generally safe and well tolerated, with skin-related adverse events reported in fewer than 1% of participants receiving active treatment.¹⁶

In an open-label safety extension study that enrolled 657 patients, treatment with FMX101 continued for as long as 40 weeks.¹⁷ In total, 291 participants completed 52 weeks of therapy. Rates and types of reported TEAEs in the open-label extension phase were similar to those seen in the phase 3 trials. Application-site TEAEs occurred in fewer than 2% of participants. Participants reported a high level of treatment satisfaction at week 52.¹⁷

In a more recent phase 3 study, 1507 participants were randomized (1:1) to once-daily minocycline foam 4% or foam vehicle for 12 weeks to further evaluate the efficacy and safety of FMX101 4% for moderate to severe acne vulgaris.¹⁸ The study met both primary end points: absolute change from baseline in the inflammatory lesion count (−16.93 vs −13.40; P<.0001) and the noninflammatory lesion count (−18.80 vs −15.89; P<.05), as well as percentage of participants with IGA treatment success at week 12 (30.80% vs 19.63%; P<.0001). The percentage reduction in the inflammatory lesion count was statistically significantly greater for minocycline foam 4% compared to vehicle as early as week 3 (P<.0001). The safety profile was found to be consistent with the 2 earlier phase 3 studies.¹⁸

Topical Minocycline in Rosacea

A similar foam formulation of minocycline (1.5% concentration) has shown benefit in 2 identical phase 3 studies.¹⁹ A total of 1522 participants were enrolled in 2 phase 3, randomized, multicenter, double-blind, vehicle-controlled, 2-arm studies in participants 18 years and older with moderate to severe papulopustular rosacea. Participants were randomized (2:1) to either minocycline foam 1.5% or vehicle once daily to the face for 12 weeks.¹⁹

Treatment was associated with a statistically significant reduction in counts of inflammatory lesions of rosacea (Study FX2016-11: −17.57 vs −15.65 [P=.003]; Study FX2016-12: −18.54 vs −14.88 [P<.0001]) and a significantly higher rate of IGA treatment success compared to vehicle (Study FX2016-11: 52.1% vs 43.0% [P=.027]; Study FX2016-12: 49.1% vs 39.0% [P=.008]), highlighting the anti-inflammatory action of the topically applied agent.¹⁹

The most common TEAE for both studies was upper respiratory tract infection; there were no serious TEAEs. Overall, 9 participants across both studies discontinued because of a TEAE (foam, 7 participants; vehicle, 2 participants).¹⁹

Clascoterone: First-in-Class Topical

Clascoterone cream 1% is a new chemical entity under investigation for the treatment of moderate to severe acne in patients 9 years and older. Clascoterone targets androgen receptors in the skin to block the effects of circulating endogenous androgens; chemically, it shares a 4-ring backbone identical to dihydrotestosterone and spironolactone (Figure 2). Clascoterone competes with dihydrotestosterone for binding to the androgen receptor to limit or block transcription of androgen-responsive genes and modify specific gene expression.²⁰

Androgens are known to promote both sebum production and inflammatory responses within the follicle, contributing to the cycle of acne.²¹ Antiandrogen therapy would, therefore, inhibit excess sebum production and directly reduce the presence of certain inflammatory mediators in skin. This effect is expected to lead to reduced follicular plugging and a reduction in growth of P acnes and its inflammatory by-products.

Direct and indirect hormonal modulation have been successfully employed to manage acne in women; however, such therapies have not been considered first-line interventions for the disease.²² Although systemic antiandrogens and hormonal modulation are effective for certain women with acne, there may be concerns about systemic exposure²³; no hormone-modulating agent has been adopted for use in men with acne.

As an androgen inhibitor, clascoterone is thought to displace androgen hormones from androgen receptors located at the sebaceous gland and hair follicle, thus inhibiting the cycle of physiologic events that leads to acne formation. Clascoterone is applied topically and acts locally on androgen receptors in the skin, with no systemic exposure seen. In phase 2 trials, clascoterone was found to be safe and effective with no systemic exposure and was suggested to have better tolerability than topical tretinoin.

Preliminary individual study analysis of data from 2 phase 3 trials showed that topical clascoterone met its primary end points, achieving statistically significantly greater rates of IGA treatment success (≥2 point reduction in IGA and score of 0 [clear] or 1 [almost clear]) at week 12 (P<.0001).²⁴ Rates of treatment success for actively treated participants were 16.1% and 18.7%, respectively, compared to 7% and 4.7%, respectively, for vehicle. The study population included both males and nonpregnant females 9 years and older who had a baseline IGA score of 3 (moderate) or 4 (severe). At baseline, participants had a mix of inflammatory lesions (≥30, to a maximum of 75) and noninflammatory lesions (≥30, to a maximum of 100).²⁴

Intention-to-treat analysis at week 12 showed a mean total lesion reduction from baseline for active treatment of 37.1% and 37.7%, respectively, compared to 28.5% and 22.2%, respectively, for controls.²⁴ Mean reductions from baseline in noninflammatory lesions for active treatment were 30.7% and 29.3%, respectively, compared to 21.9% and 15.8%, respectively, for controls. Mean reductions from baseline in inflammatory lesions for active treatment were 44.8% and 47%, respectively, compared to 36.6% and 29.8%, respectively, for controls. Similarly low rates of TEAEs were reported in active and placebo groups in both studies. No TEAE suggested systemic antiandrogen exposure.²⁴

Advancements in Cannabinoids

Advancements in pharmaceutical development of cannabinoid compounds have largely coincided with the controversial national movement to legalize medical marijuana and decriminalize recreational marijuana use. Despite the temporal connection, the 2 topics are entirely distinct. Importantly, pharmaceutical development is largely focused on the effects of cannabidiol (CBD), which is 1 of approximately 113 cannabinoids identified from Cannabis sativa. Cannabidiol is not tetrahydrocannabinol, or THC, the compound responsible for marijuana’s psychoactive effects and addictive properties; CBD does not have any psychoactive effects and is not addictive (Figure 3).²⁵

A CBD oral solution agent recently gained FDA approval for seizures associated with Lennox-Gastaut syndrome or Dravet syndrome in patients 2 years and older; it is estimated that more than 180 trials of CBD are ongoing in the United States for various indications.²⁶ A notable question in the development of CBD-based therapies is: What is the role of natural plant-derived CBD compared to a pure synthetic form of CBD? The latter is akin to a pharmaceutical process in which a single molecule is developed as the active drug.²⁷ Although the potency and composition of plant-derived CBD can vary with crop conditions, plant strains, and the extraction process, a synthetic molecule would allow for consistency in safety, potency, and pharmacokinetic properties, as well as efficacy, as a consequence.²⁶

There are intriguing data to suggest a potential use for topical CBD in the management of skin diseases, including acne vulgaris. Researchers have, for at least a decade, been investigating the role of the endocannabinoid system, which has physiologic regulatory functions in proliferation, differentiation, apoptosis and cytokine, mediator, and hormone production of various cell types in skin, hair follicles, and sebaceous glands.²⁸ Cannabidiol has been shown to suppress proliferation of sebocytes through activation of transient receptor potential vanilloid 4 ion channels and to have anti-inflammatory effects on sebocytes.²⁹ It has been shown to inhibit human keratinocyte proliferation through a non-CB1/CB2 mechanism³⁰ and to possess potent antimicrobial activity against gram-positive bacteria such as P acnes.³¹

Given these effects on sebocytes, modulation of keratinocyte proliferation, and anti-inflammatory and antibacterial effects, CBD could prove beneficial in the management of acne vulgaris. A new synthetic CBD topical formulation, BTX 1503, is under investigation for the treatment of acne vulgaris.

Early clinical data confirm both the anti-inflammatory effects of topical BTX 1503 as well as its effects on noninflammatory lesions, with 4-week reductions in inflammatory lesion counts similar to what are reported in clinical trials for leading FDA-approved topical therapies in the same time frame.

The phase 1b trial was a 4-week, open-label study in participants with moderate to severe acne vulgaris.³² The primary end point was safety, as demonstrated by the incidence of TEAE, laboratory monitoring, and assessment of cutaneous tolerability. Exploratory end points included changes in inflammatory and noninflammatory lesion counts and IGA score. A total of 21 participants aged 18 to 65 years with moderate to severe acne vulgaris were enrolled. BTX 1503 was applied topically twice daily. At baseline, eligible participants had 20 to 50 inflammatory lesions and 20 to 100 noninflammatory acne lesions on the face, an IGA of 3 (moderate) or 4 (severe), and 3 or fewer nodular or cystic lesions (>5 mm in diameter). No serious or severe TEAEs were reported; no participants withdrew due to a TEAE. Slight erythema, slight scaling, slight dryness, and slight burning and stinging were reported; there were no reports of irritant or allergic contact dermatitis. Only 1 TEAE was thought to be possibly related to treatment: mild pain at the application site.³²

In addition to presenting a potential new chemical entity for the topical treatment of acne, the novel topical vehicle formulation of BTX 1503 represents an innovative approach to drug delivery. The formulation utilizes proprietary technology to deliver high doses of drug into the skin without controversial penetration enhancers, preservatives, or other potential irritating additives. Instead, volatile excipients are used that evaporate upon application to the skin, leaving a so-called superconcentrated secondary formulation on the skin. The concentration gradient effect then drives the concentrated drug into skin. Although the formulation efficiently delivers active drug into the skin and its appendages, systemic exposure has been reported to be very low. A phase 2 randomized, double-blind, vehicle-controlled trial ongoing in the United States and Australia in 360 patients with moderate to severe acne vulgaris will provide key data to confirm the efficacy and safety of BTX 1503 (ClinicalTrials.gov Identifier NCT03573518).

Conclusion

Drug development continues to focus on the challenge of treating acne effectively and safely. Vehicle innovations are optimizing existing active drugs and creating opportunities to deliver new compounds to the skin. The approval of sarecycline as the first new chemical entity approved for acne in several years may be followed in coming years by other new actives, including clascoterone and CBD.

Hair plays an important role in identity, self-perception, and psychosocial functioning. Hair loss can be a devastating experience that decreases self-esteem and feelings of personal attractiveness while also leading to depression and anxiety.^1,2 Although increasingly popular, surgical hair restoration, including hair transplantation, is costly and carries considerable risk.

Results of nonsurgical hair restoration are not immediate and may not be as dramatic; however, they do not carry the risks or recovery associated with surgical options. Treatments such as sex steroid hormone and biologic response modifiers have been used to inhibit hair miniaturization and stabilize hair loss in cases of androgenic alopecia (AGA).³ Currently, minoxidil and finasteride are the only US Food and Drug Administration (FDA)–approved medications for the treatment of hair loss; however, other nonsurgical treatment options have gained popularity, including dutasteride, spironolactone, low-level laser therapy (LLLT), platelet-rich plasma (PRP), microneedling, stem cells, and nutraceutical supplements. We provide an overview of these treatment options to help dermatologists select appropriate therapies for the treatment of alopecia (Table).

Minoxidil

Minoxidil has been known to improve hair growth for more than 40 years. Oral minoxidil was first introduced for hypertension in the 1970s with a common adverse effect of hypertrichosis; the 2% solution was marketed for AGA shortly thereafter in 1986.⁴ Minoxidil is a biologic response modifier that is thought to promote hair growth through vasodilation and stimulation of hair follicles into the growth phase.⁵ In animal studies, topical minoxidil has been shown to shorten telogen, prolong anagen, and increase hair follicle size.^6,7 More recently, topical minoxidil was shown to have anti-inflammatory effects by downregulating IL-1, which may confer an additional role in combatting alopecia.⁸

Minoxidil is FDA approved for treatment of AGA in men and women and often is used as first-line therapy.⁹ In 3 separate meta-analyses of topical minoxidil, it was shown to be more effective than placebo for treating AGA in men and women, with a notable increase in target area hair growth.¹⁰ A study of 777 male patients treated with topical minoxidil 2% found that 45% subjectively experienced new hair growth.¹¹ However, results may vary, and research indicates that higher concentrations are more effective. In a randomized, double-blind, placebo-controlled trial of 381 women with female pattern hair loss (FPHL), minoxidil solution 2% was found to be superior to placebo after 48 weeks, with average changes in nonvellus hair counts of 20.7/cm² in the minoxidil group vs 9.4/cm² in the placebo group.¹² In a separate meta-analysis, minoxidil solution 5% demonstrated superiority to both the 2% formulation and placebo with a mean change in nonvellus hair counts of 26.0/cm^2.13

Minoxidil also has demonstrated promising benefits in preventing chemotherapy-induced alopecia. Although oncologists most often use the scalp cooling method to prevent hair loss by decreasing perfusion and uptake of cytotoxic agents, cost may be prohibitive, as it is often not reimbursable by insurance companies.^14,15 On the other hand, minoxidil is easily procured over-the-counter and has been successfully used to decrease the duration of alopecia caused by chemotherapeutic agents such as fluorouracil, doxorubicin, and cyclophosphamide, as well as endocrine therapies used to treat breast cancer in women.^16-18 Minoxidil also has been used off label to treat other forms of alopecia, including alopecia areata, telogen effluvium, eyebrow hypotrichosis, and monilethrix; however, there is inconclusive evidence for its efficacy.^5,13,19

Compared to other nonsurgical treatments for hair loss, a meta-analysis found that minoxidil was associated with the highest rate of adverse effects (AEs).^16,17 Potential side effects include pruritus or burning at the application site; irritant or allergic contact dermatitis; hypertrichosis; and cardiovascular effects, which may be due to the vasodilatory mechanism of action of minoxidil.²⁰ One randomized double-blind study found that while topical minoxidil did not affect blood pressure, it increased heart rate by 3 to 5 beats per minute, caused considerable increases in left ventricular end-diastolic volume, an increase in cardiac output (by 0.751 min^-1), and an increase in left ventricular mass (by 5 g m^-2). The authors concluded that short-term use is safe in healthy individuals, but providers should ask about history of coronary artery disease to avoid potential cardiac side effects.²¹

Patients also should be advised that at least 6 months of minoxidil therapy may be necessary.¹¹ Furthermore, measurable hair changes may disappear within 3 months if the patient chooses to discontinue treatment.²² Finally, providers must consider patient perception of improvement and hair growth while on this medication. In one study, although investigator assessments of hair growth and hair count were increased with the use of minoxidil solution 5% compared to placebo, differences in patient assessment of hair growth were not significant at 48 weeks.²² Therefore, dermatologists should address patient expectations and consider additional treatments if necessary.

Finasteride

Finasteride is an oral medication that is FDA approved at a dose of 1 mg daily for the treatment of AGA in men. It competitively inhibits the type I and type II 5α-reductase enzymes, with a strong affinity for the type II enzyme, thereby inhibiting the conversion of testosterone to dihydrotestosterone (DHT), the potent androgen responsible for terminal hair follicle miniaturization and transformation of terminal hair into vellus hair.^21,23

Finasteride has demonstrated efficacy and high tolerability in large-scale, placebo-controlled, randomized trials with only rare complications of sexual dysfunction, supporting its status as a first-line agent.^24,25 One study found that in a population of 3177 Japanese men, an overall increase in hair growth was seen in 87.1% of men receiving oral finasteride 1 mg daily, with AEs such as decreased libido occurring in only 0.7% of patients.²⁶ However, postmarketing studies described more severe complications in men taking finasteride to treat AGA or benign prostatic hyperplasia, even after the discontinuation of medication, described as postfinasteride syndrome.^27,28 These side effects include decreased libido, reduction in penis size, gynecomastia, erectile dysfunction, and ejaculation disorder, in addition to psychologic impairments, including decreased concentration, depression, and suicidal ideation, presumably due to the role of 5α-reductase interacting with the γ-aminobutyric acid (GABA_A) receptor within the central nervous system.²⁹ The incidence of persistent erectile dysfunction was reported to be as low as 1.4% in a study assessing 11,909 men prescribed up to 5 mg once daily of finasteride to treat benign prostatic hyperplasia and AGA. The incidence was higher in patients using higher doses of finasteride and longer treatment courses as well as in patients with prostate disease.²⁹ These potential side effects should be discussed with male patients prior to prescribing finasteride.

Finasteride is not FDA approved for use in women and is considered category X in pregnancy due to animal studies that demonstrated external genital abnormalities in male fetuses exposed to type II 5α-reductase inhibitors.³⁰ Despite this potential teratogenicity, finasteride is prescribed off label to treat FPHL and hirsutism. A meta-analysis of 2683 women participating in 65 studies found that finasteride, when used at dosages of 0.5 to 5 mg daily, may improve FPHL and frontal fibrosing alopecia after 6 to 12 months.³⁰ However, available studies have used varying treatment methods, yielding differing results. For example, one randomized trial of 137 postmenopausal women with FPHL and normal androgen levels found no benefit with 1 mg daily³¹; however, another trial of 87 women with normal levels of androgens found that 5 mg daily of finasteride showed significant improvements in hair quantity and thickness after 12 months (P<.01).³² Further studies are needed to assess the appropriate female population that may benefit from use of finasteride. Premenopausal women interested in this therapy should be counseled about the risk of teratogenicity, as well as potential breast tenderness, loss of libido, and menstrual irregularities.³³ Furthermore, finasteride use in women may pose a theoretical risk of breast cancer, as DHT inhibition results in conversion of excess testosterone to estrogen, thereby altering the estrogen to androgen ratio.³⁴

Dutasteride

Dutasteride is 100-times more potent than finasteride as an inhibitor of type I 5α-reductase enzyme and 3-times more potent as an inhibitor of type I 5α-reductase enzyme.³⁵ Therefore, it has been hypothesized that dutasteride may be more effective than finasteride for restoring hair loss, though it is not yet FDA approved for this indication.

Research evaluating the efficacy of dutasteride is emerging. Randomized controlled trials in men with AGA are promising and suggest reversed hair miniaturization.³⁶ One randomized trial of 153 men found that dutasteride 0.5 mg daily was superior to placebo for the treatment of hair loss, as evidenced by an increase in hair counts in dutasteride patients (12.2/cm²) compared to controls (4.7/cm²). Furthermore, 0.5-mg dutasteride resulted in significantly increased new hair growth after 24 weeks compared to a placebo control (23/cm² vs 4/cm²; P<.05).³⁷

Dutasteride also is now being used off label to treat FPHL. Little evidence-based research exists regarding the use of dutasteride in women, though 1 case report described successful treatment of FPHL after 6 months of treatment with 0.5 mg daily of dutasteride in a 46-year-old woman who showed only minimal improvement on oral finasteride.³⁸

The side-effect profile is similar to finasteride, and research in the urologic literature demonstrated that the rate of AEs is comparable between the 2 drugs, with reports of sexual side effects occurring in 11% of patients taking dutasteride 0.5 mg daily vs 14% of patients taking finasteride 5 mg daily.³⁹ In the dermatologic literature, there was no statistically significant difference between the rate of AEs, specifically sexual AEs, in patients taking dutasteride 0.5 mg daily vs finasteride 1 mg daily.³⁶ Safety of dutasteride in women is not well established. The side-effect profile described for finasteride, including the risk of potential fetal anomalies, should be discussed with women receiving dutasteride therapy.

Spironolactone

Although topical minoxidil is still considered first-line therapy for women experiencing hair loss, spironolactone is growing in popularity as an off-label treatment of FPHL, though it is not FDA approved for this indication. Spironolactone is a synthetic steroid that has been used as a potassium-sparing diuretic for more than 60 years. Its primary metabolite, canrenone, competitively inhibits aldosterone.³⁷ It is FDA approved for the treatment of essential hypertension (25–100 mg), congestive heart failure (25 mg), diuretic-induced hypokalemia (25–100 mg), and primary hyperaldosteronism (100–400 mg).^37,40 Spironolactone was serendipitously discovered to treat hirsutism, acne, and seborrhea associated with polycystic ovary syndrome.⁴¹

Androgens are well studied in male pattern hair loss, and their role in FPHL is now becoming evident, with new research supporting the role of spironolactone as a useful antiandrogen.^42,43 An Australian open-label trial randomized 80 women with biopsy-proven FPHL to receive either spironolactone 200 mg daily or cyproterone acetate, an antiandrogen used abroad, including in European countries, in conjunction with an oral contraceptive pill for premenopausal women.⁴² Spironolactone was found to be as effective as the alternate regimen, with 44% of patients experiencing hair regrowth, 44% experiencing no progression of hair loss, and only 12% experiencing continued hair loss.⁴⁴ Spironolactone used in combination with minoxidil has been shown to demonstrate greater efficacy when compared to spironolactone alone.⁴⁵ One observational study of 100 women with FPHL found that once-daily capsules of minoxidil 0.25 mg combined with once daily spironolactone 25 mg was a safe and effective treatment of FPHL.⁴⁴ Spironolactone also is considered safe and effective to treat FPHL in postmenopausal women by inhibiting the relative androgen excess.⁴⁶

The starting dose for spironolactone usually is 25 mg twice daily and increased by 50 mg daily up to 200 mg daily as tolerated. Furthermore, results should be monitored for at least 6 months to assess efficacy accurately.⁴⁷ Side effects include headache, decreased libido, menstrual irregularities, orthostatic hypotension, fatigue, and hyperkalemia. Although hyperkalemia is a known side effect of spironolactone, one study of 974 male and female participants receiving spironolactone found that only 0.72% of participants experienced mild hyperkalemia (5.1–6.0 mEq/L) with no patients experiencing moderate or severe hyperkalemia. Regardless, providers may consider checking potassium levels within 4 to 8 weeks of initiating treatment with spironolactone.⁴⁸ Other potential AEs include gynecomastia and feminization; therefore, it is not recommended for use in men.⁴² Oral contraception is recommended to prevent pregnancy in premenopausal women, as spironolactone may cause feminization of the male fetus. Because of the antiandrogenic and progestogenic effects of spironolactone, there has been a theoretical concern for risk of inducing breast cancer, especially in postmenopausal women. However, a study conducted in the United Kingdom of more than 1 million female patients older than 55 years found that there was no increased risk of breast cancer in postmenopausal women.⁴⁹

Low-Level Laser Light Therapy

Low-level laser light therapy has been used to reduce pain, treat edema, and promote would healing for almost 50 years and is now one of the few FDA-cleared devices to treat alopecia. Low-level laser light therapy uses red beam or near-infrared nonthermal lasers at a wavelength of 600 to 1000 nm and from 5 to 500 mW. The exact mechanism of hair growth stimulation is not known; however, it is believed that LLLT accelerates mitosis, stimulates hair follicle stem cells to activate follicular keratinocytes, and alters cellular metabolism by inhibiting nitric oxide from cytochrome c oxidase.⁵⁰

Trials evaluating the efficacy of LLLT laser combs for the treatment of AGA have demonstrated notable improvements in hair density. For example, one sham device–controlled, double-blind clinical trial randomized 334 men and women to treatment with either an FDA-cleared laser comb vs sham devices.⁵¹ The treatment devices were used 3 times weekly for 26 weeks. Hair counts for those treated with the 7-, 9-, and 12-beam LLLT laser combs were significantly higher than the sham after 26 weeks (P<.05), without any serious AEs being reported.⁵¹ Another study in men with AGA proved similarly efficacious results using at-home LLLT therapy of 655 nm to the scalp every other day for 16 weeks (60 treatments).⁵² However, a 24-week randomized, double-blind, sham device–controlled, multicenter trial evaluating the LLLT helmet (combining 650-nm laser with 630- and 660-nm light-emitting diodes) among male and female patients with AGA failed to show promising results. Although mean (SD) hair thickness (12.6 [9.4] in LLLT group vs 3.9 [7.3] in control group [P=.01]) and hair density (17.2 [12.1] in LLLT group vs –2.1 [18.3] in control group [P=.003]) increased significantly, there was no significant difference in subject assessment of global appearance between the 2 groups.⁵³

Low-level laser light therapy devices are available both for use at home and in office, with 650- to 900-nm wavelengths at 5 mW being the recommended dose for men and women.⁵¹ With regard to AEs, the safety profile for LLLT is relatively favorable. Adverse events can include dry skin, pruritus, scalp tenderness, irritation, and a warm sensation at the treatment site.⁵²

Platelet-Rich Plasma

Originally used in the orthopedic literature to stimulate collagen growth, PRP has since been used in dermatology to promote hair regrowth by releasing platelet-derived growth factors, vascular endothelial growth factor, epidermal growth factor, insulinlike growth factor, and fibroblast growth factors to stimulate vascularization to the dermal papillary cells.^54,55 Platelet-rich plasma is derived from the supernatant of centrifuged whole blood and then injected in the dermis of the scalp to stimulate hair growth.

Although use of PRP is not approved or cleared by the FDA for treatment of hair loss, several studies have demonstrated the efficacy of autologous PRP use for treating AGA.⁵⁶ One pilot study of 19 male and female participants given a total of 5 PRP injections monthly for 3 months and subsequently at months 4 and 7 found a statistically significant improvement in mean hair density, hair diameter, and terminal-vellus hair ratio at 1-year follow-up (P<.05). Furthermore, histomorphometric evaluation demonstrated a decrease in perivascular inflammatory infiltrate.⁵⁷ On the other hand, 2 separate studies failed to show statistically significant improvements in hair growth after use of PRP.^58,59 Varying levels of success may be due in part to lack of a standard protocol for performing PRP injections. Studies comparing efficacy of different PRP administration regimens are emerging. A trial of 40 men and women found that subdermal PRP injections administered 3 times per month with booster injections administered 3 months later was more effective than other injection regimens, including once monthly injections.^58,59 Activators such as collagen, thrombin, 10% calcium chloride, and calcium gluconate may be added to the PRP serum to promote further growth factor secretion upon platelet activation.⁶⁰ However, different means of activation are used in different trials, potentially leading to varying results in clinical trials, with no one proven superior method.^61-63 The main drawback of PRP use is that there is no consensus regarding exact concentration, utility of activators, dosing parameters, depth of injection, or frequency of sessions.⁶⁰ Transient pain and erythema are the most common side effects of PRP injections, with no major AEs reported in the literature.⁶⁴

Microneedling

Microneedling is a minimally invasive procedure that uses needles to puncture the stratum corneum of the skin.⁶⁵ It was first used cosmetically more than 20 years ago due to its ability to increase collagen and elastin formation.⁵¹ Since its discovery, microneedling has been used to reduce the appearance of scars; augment transdermal drug delivery; and treat active acne vulgaris, melasma, hyperhidrosis, and alopecia.⁶⁵ Although there are numerous at-home and professional microneedling devices on the market, only one device has been FDA cleared thus far.

Microneedling is proposed to increase hair regrowth by triggering the wound healing response, which ultimately augments the release of platelet-derived and epidermal growth factors while also activating the hair bulge.⁶⁶ Treatment often is performed with a roller instrument that uses needles 0.5- to 2.5-mm long. Topical anesthetic cream may be applied prior to treatment.⁶⁷ The treated area is then washed and an antibiotic ointment is applied.⁵⁵ Management regimens typically require daily to weekly treatments with a total of 12 to 28 weeks to demonstrate an effect.

Microneedling has demonstrated efficacy in the treatment of hair loss, especially when combined with minoxidil. One study randomized 68 patients to undergo microneedling with minoxidil solution 5% twice daily compared to a control group of minoxidil solution 5% twice daily alone. After 12 weeks, patients treated with microneedling and minoxidil had significantly higher hair counts than the control group (P<.05).⁶⁸ It is speculated that microneedling increases penetration of topical medications, including minoxidil across the skin barrier, thereby enhancing absorption of large molecules.⁶⁶

Topical PRP has been used synergistically to augment the effects of microneedling. A trial randomized 93 patients with alopecia to receive minoxidil solution 5% alone, minoxidil solution 5% plus PRP, or microneedling with PRP.⁶⁹ Hair growth was appreciated in 26 of 31 patients treated with microneedling and PRP compared to 10 of 31 and 17 of 31 in the other 2 groups, respectively. However, when hair growth occurred in the minoxidil-treated group, it occurred faster, with changes in hair growth at 12 weeks compared to 26 weeks in the microneedling group.⁶⁹ When evaluating the efficacy of microneedling and PRP, it must be noted that there is no established leading protocol for treating hair loss, which may affect the success of the treatment.

The reported side-effect profile for microneedling and PRP injections has been favorable without any major AEs noted in clinical trials.^56,64,70 The possibility of bleeding, pain, erythema, and infection should be discussed with the patient nonetheless. More severe side effects such as allergic granulomatous reactions have been reported in the literature with the use of microneedling for facial rejuvenation.⁷¹

Stem Cells

Stem cell hair therapy is a new and promising area of research with the potential to treat alopecia. Although not yet FDA approved for this indication, human umbilical cord blood–derived mesenchymal stem cells (HUCB-MSCs) have received particular attention due to their proposed ability to promote tissue differentiation and repair, to replace aged and damaged hair cells, and to promote secretion of multiple growth factors.⁷² More recently, HUCB-MSCs have been shown to successfully differentiate into human hair follicles in vitro after 3 weeks of cell culture, establishing a method for high-speed and high-purity hair follicle cell differentiation with the hope of future injections to affected areas with hair loss.⁷³ Another study found that HUCB-MSCs enhanced growth of human follicular stem cells in vitro; the authors proposed an altered Wnt/β‐catenin and JAK/STAT pathway was responsible for improved growth of hair follicular cells.⁷⁴

Although umbilical cord blood is replete with the most rapidly dividing stem cells, autologous stem cells derived from the hair follicle or mononuclear cells also may be used to treat alopecia. One recent study randomized 40 patients with AGA and alopecia areata to receive 1 session of either autologous hair follicle or mononuclear cell–derived stem cell injections to the scalp.⁷⁵ Mononuclear cells were acquired from the upper iliac crest bone marrow of patients who were treated with granulocyte colony-stimulating factor 3 days prior to the procedure. Follicular stem cells were taken from 4-mm punch biopsies of the unaffected scalp. After 6 months, there was a notable improvement in hair growth confirmed by immunostaining and dermoscopy, without a significant difference between the forms of autologous stem cell source. Of note, 45% of study patients with alopecia areata showed recurrence of disease at 1-year follow-up. The most common AEs were scalp dermatitis in 20% of participants. Participants who underwent bone marrow biopsy experienced bone pain, hematoma, and granulocyte colony-stimulating factor–induced fatigue and chills.⁷⁵

Furthermore, the cost of stem cell therapy may be prohibitive. Therefore, although stem cell therapy is a novel and promising treatment for hair loss, future research is necessary to establish safety, efficacy, best practices, and accessibility.

Supplements

Patients failing routine treatments for alopecia may turn to holistic therapies. Nutrafol (Nutraceutical Wellness Inc), a novel nutraceutical product, is one such option that has been described for its anti-inflammatory, adaptogenic, antioxidant, and DHT-inhibiting properties. This supplement is not FDA approved or cleared, and large-scale clinical trials are lacking; however, one randomized controlled trial of 40 women with self-reported hair loss found a statistically significant increase in the number of terminal and vellus hair based on phototrichograms performed after 90 and 180 days (P=.009), with no AEs reported. This study, however, was limited by a small sample size.⁷⁶

Lamdapil (ISDIN) is another oral supplement being investigated for hair loss. It contains L-cystine amino acids; zinc; vitamins B₃, B₅, B₆; biotin; and the plant extract Serenoa repens.⁷¹Serenoa repens has reported activity inhibiting the enzyme 5α-reductase with the other vitamins, and amino acids are thought to maintain keratin and collagen growth in normal hair.⁷⁷ One randomized trial investigated use of Lamdapil capsules in a total of 70 patients, which included men with AGA and women experiencing telogen effluvium. For men, the anagen-telogen ratio increased in the Lamdapil-treated group by 23.4%, indicating that more hair was in the growing phase compared to placebo (P<.05). Women with telogen effluvium experienced a significantly greater improvement in the hair-pull test compared to placebo (P<.05).⁷⁷

Marine-derived nutraceutical substances also have been investigated for their role in treating hair loss. Viviscal, originally marketed under the name Hairgain, is one such supplement, which was shown to significantly reduce hair shedding at 3 and 6 months in a group of 96 premenopausal women diagnosed with subclinical hair thinning (P<.05). Additionally, phototrichogram images demonstrated a statistically significant increase in the mean velluslike hair diameter at 6 months compared to baseline.⁷⁸

Although nutraceutical products are not first-line therapy for hair loss, dermatologists may recommend these treatments in patients refusing prescription medications, specifically requesting a natural treatment, or in addition to a first-line agent such as minoxidil. It must be noted, however, that both supplements are new, and there is need for further investigation on their efficacy, safety, and dosing, as neither is FDA regulated.

Conclusion

Hair loss affects millions of Americans each year and has detrimental effects on self-esteem and psychosocial functioning. Nonsurgical treatment options will undoubtedly continue to intrigue patients, as they are often less costly and do not carry risks associated with surgery. Minoxidil, finasteride, and LLLT remain staples of therapy, with the strongest evidence supporting their safety and efficacy. Numerous other treatment options are emerging, including PRP, microneedling, mesenchymal and autologous stem cell therapy, and oral supplements, though further research must be conducted to establish dosing, safety, and best practices. Physicians must discuss patient preference and anticipated length of treatment when discussing alopecia treatment to maximize patient satisfaction.

Hair plays an important role in identity, self-perception, and psychosocial functioning. Hair loss can be a devastating experience that decreases self-esteem and feelings of personal attractiveness while also leading to depression and anxiety.^1,2 Although increasingly popular, surgical hair restoration, including hair transplantation, is costly and carries considerable risk.

Results of nonsurgical hair restoration are not immediate and may not be as dramatic; however, they do not carry the risks or recovery associated with surgical options. Treatments such as sex steroid hormone and biologic response modifiers have been used to inhibit hair miniaturization and stabilize hair loss in cases of androgenic alopecia (AGA).³ Currently, minoxidil and finasteride are the only US Food and Drug Administration (FDA)–approved medications for the treatment of hair loss; however, other nonsurgical treatment options have gained popularity, including dutasteride, spironolactone, low-level laser therapy (LLLT), platelet-rich plasma (PRP), microneedling, stem cells, and nutraceutical supplements. We provide an overview of these treatment options to help dermatologists select appropriate therapies for the treatment of alopecia (Table).

Minoxidil

Minoxidil has been known to improve hair growth for more than 40 years. Oral minoxidil was first introduced for hypertension in the 1970s with a common adverse effect of hypertrichosis; the 2% solution was marketed for AGA shortly thereafter in 1986.⁴ Minoxidil is a biologic response modifier that is thought to promote hair growth through vasodilation and stimulation of hair follicles into the growth phase.⁵ In animal studies, topical minoxidil has been shown to shorten telogen, prolong anagen, and increase hair follicle size.^6,7 More recently, topical minoxidil was shown to have anti-inflammatory effects by downregulating IL-1, which may confer an additional role in combatting alopecia.⁸

Minoxidil is FDA approved for treatment of AGA in men and women and often is used as first-line therapy.⁹ In 3 separate meta-analyses of topical minoxidil, it was shown to be more effective than placebo for treating AGA in men and women, with a notable increase in target area hair growth.¹⁰ A study of 777 male patients treated with topical minoxidil 2% found that 45% subjectively experienced new hair growth.¹¹ However, results may vary, and research indicates that higher concentrations are more effective. In a randomized, double-blind, placebo-controlled trial of 381 women with female pattern hair loss (FPHL), minoxidil solution 2% was found to be superior to placebo after 48 weeks, with average changes in nonvellus hair counts of 20.7/cm² in the minoxidil group vs 9.4/cm² in the placebo group.¹² In a separate meta-analysis, minoxidil solution 5% demonstrated superiority to both the 2% formulation and placebo with a mean change in nonvellus hair counts of 26.0/cm^2.13

Minoxidil also has demonstrated promising benefits in preventing chemotherapy-induced alopecia. Although oncologists most often use the scalp cooling method to prevent hair loss by decreasing perfusion and uptake of cytotoxic agents, cost may be prohibitive, as it is often not reimbursable by insurance companies.^14,15 On the other hand, minoxidil is easily procured over-the-counter and has been successfully used to decrease the duration of alopecia caused by chemotherapeutic agents such as fluorouracil, doxorubicin, and cyclophosphamide, as well as endocrine therapies used to treat breast cancer in women.^16-18 Minoxidil also has been used off label to treat other forms of alopecia, including alopecia areata, telogen effluvium, eyebrow hypotrichosis, and monilethrix; however, there is inconclusive evidence for its efficacy.^5,13,19

Compared to other nonsurgical treatments for hair loss, a meta-analysis found that minoxidil was associated with the highest rate of adverse effects (AEs).^16,17 Potential side effects include pruritus or burning at the application site; irritant or allergic contact dermatitis; hypertrichosis; and cardiovascular effects, which may be due to the vasodilatory mechanism of action of minoxidil.²⁰ One randomized double-blind study found that while topical minoxidil did not affect blood pressure, it increased heart rate by 3 to 5 beats per minute, caused considerable increases in left ventricular end-diastolic volume, an increase in cardiac output (by 0.751 min^-1), and an increase in left ventricular mass (by 5 g m^-2). The authors concluded that short-term use is safe in healthy individuals, but providers should ask about history of coronary artery disease to avoid potential cardiac side effects.²¹

Patients also should be advised that at least 6 months of minoxidil therapy may be necessary.¹¹ Furthermore, measurable hair changes may disappear within 3 months if the patient chooses to discontinue treatment.²² Finally, providers must consider patient perception of improvement and hair growth while on this medication. In one study, although investigator assessments of hair growth and hair count were increased with the use of minoxidil solution 5% compared to placebo, differences in patient assessment of hair growth were not significant at 48 weeks.²² Therefore, dermatologists should address patient expectations and consider additional treatments if necessary.

Finasteride

Finasteride is an oral medication that is FDA approved at a dose of 1 mg daily for the treatment of AGA in men. It competitively inhibits the type I and type II 5α-reductase enzymes, with a strong affinity for the type II enzyme, thereby inhibiting the conversion of testosterone to dihydrotestosterone (DHT), the potent androgen responsible for terminal hair follicle miniaturization and transformation of terminal hair into vellus hair.^21,23

Finasteride has demonstrated efficacy and high tolerability in large-scale, placebo-controlled, randomized trials with only rare complications of sexual dysfunction, supporting its status as a first-line agent.^24,25 One study found that in a population of 3177 Japanese men, an overall increase in hair growth was seen in 87.1% of men receiving oral finasteride 1 mg daily, with AEs such as decreased libido occurring in only 0.7% of patients.²⁶ However, postmarketing studies described more severe complications in men taking finasteride to treat AGA or benign prostatic hyperplasia, even after the discontinuation of medication, described as postfinasteride syndrome.^27,28 These side effects include decreased libido, reduction in penis size, gynecomastia, erectile dysfunction, and ejaculation disorder, in addition to psychologic impairments, including decreased concentration, depression, and suicidal ideation, presumably due to the role of 5α-reductase interacting with the γ-aminobutyric acid (GABA_A) receptor within the central nervous system.²⁹ The incidence of persistent erectile dysfunction was reported to be as low as 1.4% in a study assessing 11,909 men prescribed up to 5 mg once daily of finasteride to treat benign prostatic hyperplasia and AGA. The incidence was higher in patients using higher doses of finasteride and longer treatment courses as well as in patients with prostate disease.²⁹ These potential side effects should be discussed with male patients prior to prescribing finasteride.

Finasteride is not FDA approved for use in women and is considered category X in pregnancy due to animal studies that demonstrated external genital abnormalities in male fetuses exposed to type II 5α-reductase inhibitors.³⁰ Despite this potential teratogenicity, finasteride is prescribed off label to treat FPHL and hirsutism. A meta-analysis of 2683 women participating in 65 studies found that finasteride, when used at dosages of 0.5 to 5 mg daily, may improve FPHL and frontal fibrosing alopecia after 6 to 12 months.³⁰ However, available studies have used varying treatment methods, yielding differing results. For example, one randomized trial of 137 postmenopausal women with FPHL and normal androgen levels found no benefit with 1 mg daily³¹; however, another trial of 87 women with normal levels of androgens found that 5 mg daily of finasteride showed significant improvements in hair quantity and thickness after 12 months (P<.01).³² Further studies are needed to assess the appropriate female population that may benefit from use of finasteride. Premenopausal women interested in this therapy should be counseled about the risk of teratogenicity, as well as potential breast tenderness, loss of libido, and menstrual irregularities.³³ Furthermore, finasteride use in women may pose a theoretical risk of breast cancer, as DHT inhibition results in conversion of excess testosterone to estrogen, thereby altering the estrogen to androgen ratio.³⁴

Dutasteride

Dutasteride is 100-times more potent than finasteride as an inhibitor of type I 5α-reductase enzyme and 3-times more potent as an inhibitor of type I 5α-reductase enzyme.³⁵ Therefore, it has been hypothesized that dutasteride may be more effective than finasteride for restoring hair loss, though it is not yet FDA approved for this indication.

Research evaluating the efficacy of dutasteride is emerging. Randomized controlled trials in men with AGA are promising and suggest reversed hair miniaturization.³⁶ One randomized trial of 153 men found that dutasteride 0.5 mg daily was superior to placebo for the treatment of hair loss, as evidenced by an increase in hair counts in dutasteride patients (12.2/cm²) compared to controls (4.7/cm²). Furthermore, 0.5-mg dutasteride resulted in significantly increased new hair growth after 24 weeks compared to a placebo control (23/cm² vs 4/cm²; P<.05).³⁷

Dutasteride also is now being used off label to treat FPHL. Little evidence-based research exists regarding the use of dutasteride in women, though 1 case report described successful treatment of FPHL after 6 months of treatment with 0.5 mg daily of dutasteride in a 46-year-old woman who showed only minimal improvement on oral finasteride.³⁸

The side-effect profile is similar to finasteride, and research in the urologic literature demonstrated that the rate of AEs is comparable between the 2 drugs, with reports of sexual side effects occurring in 11% of patients taking dutasteride 0.5 mg daily vs 14% of patients taking finasteride 5 mg daily.³⁹ In the dermatologic literature, there was no statistically significant difference between the rate of AEs, specifically sexual AEs, in patients taking dutasteride 0.5 mg daily vs finasteride 1 mg daily.³⁶ Safety of dutasteride in women is not well established. The side-effect profile described for finasteride, including the risk of potential fetal anomalies, should be discussed with women receiving dutasteride therapy.

Spironolactone

Although topical minoxidil is still considered first-line therapy for women experiencing hair loss, spironolactone is growing in popularity as an off-label treatment of FPHL, though it is not FDA approved for this indication. Spironolactone is a synthetic steroid that has been used as a potassium-sparing diuretic for more than 60 years. Its primary metabolite, canrenone, competitively inhibits aldosterone.³⁷ It is FDA approved for the treatment of essential hypertension (25–100 mg), congestive heart failure (25 mg), diuretic-induced hypokalemia (25–100 mg), and primary hyperaldosteronism (100–400 mg).^37,40 Spironolactone was serendipitously discovered to treat hirsutism, acne, and seborrhea associated with polycystic ovary syndrome.⁴¹

Androgens are well studied in male pattern hair loss, and their role in FPHL is now becoming evident, with new research supporting the role of spironolactone as a useful antiandrogen.^42,43 An Australian open-label trial randomized 80 women with biopsy-proven FPHL to receive either spironolactone 200 mg daily or cyproterone acetate, an antiandrogen used abroad, including in European countries, in conjunction with an oral contraceptive pill for premenopausal women.⁴² Spironolactone was found to be as effective as the alternate regimen, with 44% of patients experiencing hair regrowth, 44% experiencing no progression of hair loss, and only 12% experiencing continued hair loss.⁴⁴ Spironolactone used in combination with minoxidil has been shown to demonstrate greater efficacy when compared to spironolactone alone.⁴⁵ One observational study of 100 women with FPHL found that once-daily capsules of minoxidil 0.25 mg combined with once daily spironolactone 25 mg was a safe and effective treatment of FPHL.⁴⁴ Spironolactone also is considered safe and effective to treat FPHL in postmenopausal women by inhibiting the relative androgen excess.⁴⁶

The starting dose for spironolactone usually is 25 mg twice daily and increased by 50 mg daily up to 200 mg daily as tolerated. Furthermore, results should be monitored for at least 6 months to assess efficacy accurately.⁴⁷ Side effects include headache, decreased libido, menstrual irregularities, orthostatic hypotension, fatigue, and hyperkalemia. Although hyperkalemia is a known side effect of spironolactone, one study of 974 male and female participants receiving spironolactone found that only 0.72% of participants experienced mild hyperkalemia (5.1–6.0 mEq/L) with no patients experiencing moderate or severe hyperkalemia. Regardless, providers may consider checking potassium levels within 4 to 8 weeks of initiating treatment with spironolactone.⁴⁸ Other potential AEs include gynecomastia and feminization; therefore, it is not recommended for use in men.⁴² Oral contraception is recommended to prevent pregnancy in premenopausal women, as spironolactone may cause feminization of the male fetus. Because of the antiandrogenic and progestogenic effects of spironolactone, there has been a theoretical concern for risk of inducing breast cancer, especially in postmenopausal women. However, a study conducted in the United Kingdom of more than 1 million female patients older than 55 years found that there was no increased risk of breast cancer in postmenopausal women.⁴⁹

Low-Level Laser Light Therapy

Low-level laser light therapy has been used to reduce pain, treat edema, and promote would healing for almost 50 years and is now one of the few FDA-cleared devices to treat alopecia. Low-level laser light therapy uses red beam or near-infrared nonthermal lasers at a wavelength of 600 to 1000 nm and from 5 to 500 mW. The exact mechanism of hair growth stimulation is not known; however, it is believed that LLLT accelerates mitosis, stimulates hair follicle stem cells to activate follicular keratinocytes, and alters cellular metabolism by inhibiting nitric oxide from cytochrome c oxidase.⁵⁰

Trials evaluating the efficacy of LLLT laser combs for the treatment of AGA have demonstrated notable improvements in hair density. For example, one sham device–controlled, double-blind clinical trial randomized 334 men and women to treatment with either an FDA-cleared laser comb vs sham devices.⁵¹ The treatment devices were used 3 times weekly for 26 weeks. Hair counts for those treated with the 7-, 9-, and 12-beam LLLT laser combs were significantly higher than the sham after 26 weeks (P<.05), without any serious AEs being reported.⁵¹ Another study in men with AGA proved similarly efficacious results using at-home LLLT therapy of 655 nm to the scalp every other day for 16 weeks (60 treatments).⁵² However, a 24-week randomized, double-blind, sham device–controlled, multicenter trial evaluating the LLLT helmet (combining 650-nm laser with 630- and 660-nm light-emitting diodes) among male and female patients with AGA failed to show promising results. Although mean (SD) hair thickness (12.6 [9.4] in LLLT group vs 3.9 [7.3] in control group [P=.01]) and hair density (17.2 [12.1] in LLLT group vs –2.1 [18.3] in control group [P=.003]) increased significantly, there was no significant difference in subject assessment of global appearance between the 2 groups.⁵³

Low-level laser light therapy devices are available both for use at home and in office, with 650- to 900-nm wavelengths at 5 mW being the recommended dose for men and women.⁵¹ With regard to AEs, the safety profile for LLLT is relatively favorable. Adverse events can include dry skin, pruritus, scalp tenderness, irritation, and a warm sensation at the treatment site.⁵²

Platelet-Rich Plasma

Originally used in the orthopedic literature to stimulate collagen growth, PRP has since been used in dermatology to promote hair regrowth by releasing platelet-derived growth factors, vascular endothelial growth factor, epidermal growth factor, insulinlike growth factor, and fibroblast growth factors to stimulate vascularization to the dermal papillary cells.^54,55 Platelet-rich plasma is derived from the supernatant of centrifuged whole blood and then injected in the dermis of the scalp to stimulate hair growth.

Although use of PRP is not approved or cleared by the FDA for treatment of hair loss, several studies have demonstrated the efficacy of autologous PRP use for treating AGA.⁵⁶ One pilot study of 19 male and female participants given a total of 5 PRP injections monthly for 3 months and subsequently at months 4 and 7 found a statistically significant improvement in mean hair density, hair diameter, and terminal-vellus hair ratio at 1-year follow-up (P<.05). Furthermore, histomorphometric evaluation demonstrated a decrease in perivascular inflammatory infiltrate.⁵⁷ On the other hand, 2 separate studies failed to show statistically significant improvements in hair growth after use of PRP.^58,59 Varying levels of success may be due in part to lack of a standard protocol for performing PRP injections. Studies comparing efficacy of different PRP administration regimens are emerging. A trial of 40 men and women found that subdermal PRP injections administered 3 times per month with booster injections administered 3 months later was more effective than other injection regimens, including once monthly injections.^58,59 Activators such as collagen, thrombin, 10% calcium chloride, and calcium gluconate may be added to the PRP serum to promote further growth factor secretion upon platelet activation.⁶⁰ However, different means of activation are used in different trials, potentially leading to varying results in clinical trials, with no one proven superior method.^61-63 The main drawback of PRP use is that there is no consensus regarding exact concentration, utility of activators, dosing parameters, depth of injection, or frequency of sessions.⁶⁰ Transient pain and erythema are the most common side effects of PRP injections, with no major AEs reported in the literature.⁶⁴

Microneedling

Microneedling is a minimally invasive procedure that uses needles to puncture the stratum corneum of the skin.⁶⁵ It was first used cosmetically more than 20 years ago due to its ability to increase collagen and elastin formation.⁵¹ Since its discovery, microneedling has been used to reduce the appearance of scars; augment transdermal drug delivery; and treat active acne vulgaris, melasma, hyperhidrosis, and alopecia.⁶⁵ Although there are numerous at-home and professional microneedling devices on the market, only one device has been FDA cleared thus far.

Microneedling is proposed to increase hair regrowth by triggering the wound healing response, which ultimately augments the release of platelet-derived and epidermal growth factors while also activating the hair bulge.⁶⁶ Treatment often is performed with a roller instrument that uses needles 0.5- to 2.5-mm long. Topical anesthetic cream may be applied prior to treatment.⁶⁷ The treated area is then washed and an antibiotic ointment is applied.⁵⁵ Management regimens typically require daily to weekly treatments with a total of 12 to 28 weeks to demonstrate an effect.

Microneedling has demonstrated efficacy in the treatment of hair loss, especially when combined with minoxidil. One study randomized 68 patients to undergo microneedling with minoxidil solution 5% twice daily compared to a control group of minoxidil solution 5% twice daily alone. After 12 weeks, patients treated with microneedling and minoxidil had significantly higher hair counts than the control group (P<.05).⁶⁸ It is speculated that microneedling increases penetration of topical medications, including minoxidil across the skin barrier, thereby enhancing absorption of large molecules.⁶⁶

Topical PRP has been used synergistically to augment the effects of microneedling. A trial randomized 93 patients with alopecia to receive minoxidil solution 5% alone, minoxidil solution 5% plus PRP, or microneedling with PRP.⁶⁹ Hair growth was appreciated in 26 of 31 patients treated with microneedling and PRP compared to 10 of 31 and 17 of 31 in the other 2 groups, respectively. However, when hair growth occurred in the minoxidil-treated group, it occurred faster, with changes in hair growth at 12 weeks compared to 26 weeks in the microneedling group.⁶⁹ When evaluating the efficacy of microneedling and PRP, it must be noted that there is no established leading protocol for treating hair loss, which may affect the success of the treatment.

The reported side-effect profile for microneedling and PRP injections has been favorable without any major AEs noted in clinical trials.^56,64,70 The possibility of bleeding, pain, erythema, and infection should be discussed with the patient nonetheless. More severe side effects such as allergic granulomatous reactions have been reported in the literature with the use of microneedling for facial rejuvenation.⁷¹

Stem Cells

Stem cell hair therapy is a new and promising area of research with the potential to treat alopecia. Although not yet FDA approved for this indication, human umbilical cord blood–derived mesenchymal stem cells (HUCB-MSCs) have received particular attention due to their proposed ability to promote tissue differentiation and repair, to replace aged and damaged hair cells, and to promote secretion of multiple growth factors.⁷² More recently, HUCB-MSCs have been shown to successfully differentiate into human hair follicles in vitro after 3 weeks of cell culture, establishing a method for high-speed and high-purity hair follicle cell differentiation with the hope of future injections to affected areas with hair loss.⁷³ Another study found that HUCB-MSCs enhanced growth of human follicular stem cells in vitro; the authors proposed an altered Wnt/β‐catenin and JAK/STAT pathway was responsible for improved growth of hair follicular cells.⁷⁴

Although umbilical cord blood is replete with the most rapidly dividing stem cells, autologous stem cells derived from the hair follicle or mononuclear cells also may be used to treat alopecia. One recent study randomized 40 patients with AGA and alopecia areata to receive 1 session of either autologous hair follicle or mononuclear cell–derived stem cell injections to the scalp.⁷⁵ Mononuclear cells were acquired from the upper iliac crest bone marrow of patients who were treated with granulocyte colony-stimulating factor 3 days prior to the procedure. Follicular stem cells were taken from 4-mm punch biopsies of the unaffected scalp. After 6 months, there was a notable improvement in hair growth confirmed by immunostaining and dermoscopy, without a significant difference between the forms of autologous stem cell source. Of note, 45% of study patients with alopecia areata showed recurrence of disease at 1-year follow-up. The most common AEs were scalp dermatitis in 20% of participants. Participants who underwent bone marrow biopsy experienced bone pain, hematoma, and granulocyte colony-stimulating factor–induced fatigue and chills.⁷⁵

Furthermore, the cost of stem cell therapy may be prohibitive. Therefore, although stem cell therapy is a novel and promising treatment for hair loss, future research is necessary to establish safety, efficacy, best practices, and accessibility.

Supplements

Patients failing routine treatments for alopecia may turn to holistic therapies. Nutrafol (Nutraceutical Wellness Inc), a novel nutraceutical product, is one such option that has been described for its anti-inflammatory, adaptogenic, antioxidant, and DHT-inhibiting properties. This supplement is not FDA approved or cleared, and large-scale clinical trials are lacking; however, one randomized controlled trial of 40 women with self-reported hair loss found a statistically significant increase in the number of terminal and vellus hair based on phototrichograms performed after 90 and 180 days (P=.009), with no AEs reported. This study, however, was limited by a small sample size.⁷⁶

Lamdapil (ISDIN) is another oral supplement being investigated for hair loss. It contains L-cystine amino acids; zinc; vitamins B₃, B₅, B₆; biotin; and the plant extract Serenoa repens.⁷¹Serenoa repens has reported activity inhibiting the enzyme 5α-reductase with the other vitamins, and amino acids are thought to maintain keratin and collagen growth in normal hair.⁷⁷ One randomized trial investigated use of Lamdapil capsules in a total of 70 patients, which included men with AGA and women experiencing telogen effluvium. For men, the anagen-telogen ratio increased in the Lamdapil-treated group by 23.4%, indicating that more hair was in the growing phase compared to placebo (P<.05). Women with telogen effluvium experienced a significantly greater improvement in the hair-pull test compared to placebo (P<.05).⁷⁷

Marine-derived nutraceutical substances also have been investigated for their role in treating hair loss. Viviscal, originally marketed under the name Hairgain, is one such supplement, which was shown to significantly reduce hair shedding at 3 and 6 months in a group of 96 premenopausal women diagnosed with subclinical hair thinning (P<.05). Additionally, phototrichogram images demonstrated a statistically significant increase in the mean velluslike hair diameter at 6 months compared to baseline.⁷⁸

Although nutraceutical products are not first-line therapy for hair loss, dermatologists may recommend these treatments in patients refusing prescription medications, specifically requesting a natural treatment, or in addition to a first-line agent such as minoxidil. It must be noted, however, that both supplements are new, and there is need for further investigation on their efficacy, safety, and dosing, as neither is FDA regulated.

Conclusion

Hair loss affects millions of Americans each year and has detrimental effects on self-esteem and psychosocial functioning. Nonsurgical treatment options will undoubtedly continue to intrigue patients, as they are often less costly and do not carry risks associated with surgery. Minoxidil, finasteride, and LLLT remain staples of therapy, with the strongest evidence supporting their safety and efficacy. Numerous other treatment options are emerging, including PRP, microneedling, mesenchymal and autologous stem cell therapy, and oral supplements, though further research must be conducted to establish dosing, safety, and best practices. Physicians must discuss patient preference and anticipated length of treatment when discussing alopecia treatment to maximize patient satisfaction.

Hair plays an important role in identity, self-perception, and psychosocial functioning. Hair loss can be a devastating experience that decreases self-esteem and feelings of personal attractiveness while also leading to depression and anxiety.^1,2 Although increasingly popular, surgical hair restoration, including hair transplantation, is costly and carries considerable risk.

Results of nonsurgical hair restoration are not immediate and may not be as dramatic; however, they do not carry the risks or recovery associated with surgical options. Treatments such as sex steroid hormone and biologic response modifiers have been used to inhibit hair miniaturization and stabilize hair loss in cases of androgenic alopecia (AGA).³ Currently, minoxidil and finasteride are the only US Food and Drug Administration (FDA)–approved medications for the treatment of hair loss; however, other nonsurgical treatment options have gained popularity, including dutasteride, spironolactone, low-level laser therapy (LLLT), platelet-rich plasma (PRP), microneedling, stem cells, and nutraceutical supplements. We provide an overview of these treatment options to help dermatologists select appropriate therapies for the treatment of alopecia (Table).

Minoxidil

Minoxidil has been known to improve hair growth for more than 40 years. Oral minoxidil was first introduced for hypertension in the 1970s with a common adverse effect of hypertrichosis; the 2% solution was marketed for AGA shortly thereafter in 1986.⁴ Minoxidil is a biologic response modifier that is thought to promote hair growth through vasodilation and stimulation of hair follicles into the growth phase.⁵ In animal studies, topical minoxidil has been shown to shorten telogen, prolong anagen, and increase hair follicle size.^6,7 More recently, topical minoxidil was shown to have anti-inflammatory effects by downregulating IL-1, which may confer an additional role in combatting alopecia.⁸

Minoxidil is FDA approved for treatment of AGA in men and women and often is used as first-line therapy.⁹ In 3 separate meta-analyses of topical minoxidil, it was shown to be more effective than placebo for treating AGA in men and women, with a notable increase in target area hair growth.¹⁰ A study of 777 male patients treated with topical minoxidil 2% found that 45% subjectively experienced new hair growth.¹¹ However, results may vary, and research indicates that higher concentrations are more effective. In a randomized, double-blind, placebo-controlled trial of 381 women with female pattern hair loss (FPHL), minoxidil solution 2% was found to be superior to placebo after 48 weeks, with average changes in nonvellus hair counts of 20.7/cm² in the minoxidil group vs 9.4/cm² in the placebo group.¹² In a separate meta-analysis, minoxidil solution 5% demonstrated superiority to both the 2% formulation and placebo with a mean change in nonvellus hair counts of 26.0/cm^2.13

Minoxidil also has demonstrated promising benefits in preventing chemotherapy-induced alopecia. Although oncologists most often use the scalp cooling method to prevent hair loss by decreasing perfusion and uptake of cytotoxic agents, cost may be prohibitive, as it is often not reimbursable by insurance companies.^14,15 On the other hand, minoxidil is easily procured over-the-counter and has been successfully used to decrease the duration of alopecia caused by chemotherapeutic agents such as fluorouracil, doxorubicin, and cyclophosphamide, as well as endocrine therapies used to treat breast cancer in women.^16-18 Minoxidil also has been used off label to treat other forms of alopecia, including alopecia areata, telogen effluvium, eyebrow hypotrichosis, and monilethrix; however, there is inconclusive evidence for its efficacy.^5,13,19

Compared to other nonsurgical treatments for hair loss, a meta-analysis found that minoxidil was associated with the highest rate of adverse effects (AEs).^16,17 Potential side effects include pruritus or burning at the application site; irritant or allergic contact dermatitis; hypertrichosis; and cardiovascular effects, which may be due to the vasodilatory mechanism of action of minoxidil.²⁰ One randomized double-blind study found that while topical minoxidil did not affect blood pressure, it increased heart rate by 3 to 5 beats per minute, caused considerable increases in left ventricular end-diastolic volume, an increase in cardiac output (by 0.751 min^-1), and an increase in left ventricular mass (by 5 g m^-2). The authors concluded that short-term use is safe in healthy individuals, but providers should ask about history of coronary artery disease to avoid potential cardiac side effects.²¹

Patients also should be advised that at least 6 months of minoxidil therapy may be necessary.¹¹ Furthermore, measurable hair changes may disappear within 3 months if the patient chooses to discontinue treatment.²² Finally, providers must consider patient perception of improvement and hair growth while on this medication. In one study, although investigator assessments of hair growth and hair count were increased with the use of minoxidil solution 5% compared to placebo, differences in patient assessment of hair growth were not significant at 48 weeks.²² Therefore, dermatologists should address patient expectations and consider additional treatments if necessary.

Finasteride

Finasteride is an oral medication that is FDA approved at a dose of 1 mg daily for the treatment of AGA in men. It competitively inhibits the type I and type II 5α-reductase enzymes, with a strong affinity for the type II enzyme, thereby inhibiting the conversion of testosterone to dihydrotestosterone (DHT), the potent androgen responsible for terminal hair follicle miniaturization and transformation of terminal hair into vellus hair.^21,23

Finasteride has demonstrated efficacy and high tolerability in large-scale, placebo-controlled, randomized trials with only rare complications of sexual dysfunction, supporting its status as a first-line agent.^24,25 One study found that in a population of 3177 Japanese men, an overall increase in hair growth was seen in 87.1% of men receiving oral finasteride 1 mg daily, with AEs such as decreased libido occurring in only 0.7% of patients.²⁶ However, postmarketing studies described more severe complications in men taking finasteride to treat AGA or benign prostatic hyperplasia, even after the discontinuation of medication, described as postfinasteride syndrome.^27,28 These side effects include decreased libido, reduction in penis size, gynecomastia, erectile dysfunction, and ejaculation disorder, in addition to psychologic impairments, including decreased concentration, depression, and suicidal ideation, presumably due to the role of 5α-reductase interacting with the γ-aminobutyric acid (GABA_A) receptor within the central nervous system.²⁹ The incidence of persistent erectile dysfunction was reported to be as low as 1.4% in a study assessing 11,909 men prescribed up to 5 mg once daily of finasteride to treat benign prostatic hyperplasia and AGA. The incidence was higher in patients using higher doses of finasteride and longer treatment courses as well as in patients with prostate disease.²⁹ These potential side effects should be discussed with male patients prior to prescribing finasteride.

Finasteride is not FDA approved for use in women and is considered category X in pregnancy due to animal studies that demonstrated external genital abnormalities in male fetuses exposed to type II 5α-reductase inhibitors.³⁰ Despite this potential teratogenicity, finasteride is prescribed off label to treat FPHL and hirsutism. A meta-analysis of 2683 women participating in 65 studies found that finasteride, when used at dosages of 0.5 to 5 mg daily, may improve FPHL and frontal fibrosing alopecia after 6 to 12 months.³⁰ However, available studies have used varying treatment methods, yielding differing results. For example, one randomized trial of 137 postmenopausal women with FPHL and normal androgen levels found no benefit with 1 mg daily³¹; however, another trial of 87 women with normal levels of androgens found that 5 mg daily of finasteride showed significant improvements in hair quantity and thickness after 12 months (P<.01).³² Further studies are needed to assess the appropriate female population that may benefit from use of finasteride. Premenopausal women interested in this therapy should be counseled about the risk of teratogenicity, as well as potential breast tenderness, loss of libido, and menstrual irregularities.³³ Furthermore, finasteride use in women may pose a theoretical risk of breast cancer, as DHT inhibition results in conversion of excess testosterone to estrogen, thereby altering the estrogen to androgen ratio.³⁴

Dutasteride

Dutasteride is 100-times more potent than finasteride as an inhibitor of type I 5α-reductase enzyme and 3-times more potent as an inhibitor of type I 5α-reductase enzyme.³⁵ Therefore, it has been hypothesized that dutasteride may be more effective than finasteride for restoring hair loss, though it is not yet FDA approved for this indication.

Research evaluating the efficacy of dutasteride is emerging. Randomized controlled trials in men with AGA are promising and suggest reversed hair miniaturization.³⁶ One randomized trial of 153 men found that dutasteride 0.5 mg daily was superior to placebo for the treatment of hair loss, as evidenced by an increase in hair counts in dutasteride patients (12.2/cm²) compared to controls (4.7/cm²). Furthermore, 0.5-mg dutasteride resulted in significantly increased new hair growth after 24 weeks compared to a placebo control (23/cm² vs 4/cm²; P<.05).³⁷

Dutasteride also is now being used off label to treat FPHL. Little evidence-based research exists regarding the use of dutasteride in women, though 1 case report described successful treatment of FPHL after 6 months of treatment with 0.5 mg daily of dutasteride in a 46-year-old woman who showed only minimal improvement on oral finasteride.³⁸

The side-effect profile is similar to finasteride, and research in the urologic literature demonstrated that the rate of AEs is comparable between the 2 drugs, with reports of sexual side effects occurring in 11% of patients taking dutasteride 0.5 mg daily vs 14% of patients taking finasteride 5 mg daily.³⁹ In the dermatologic literature, there was no statistically significant difference between the rate of AEs, specifically sexual AEs, in patients taking dutasteride 0.5 mg daily vs finasteride 1 mg daily.³⁶ Safety of dutasteride in women is not well established. The side-effect profile described for finasteride, including the risk of potential fetal anomalies, should be discussed with women receiving dutasteride therapy.

Spironolactone

Although topical minoxidil is still considered first-line therapy for women experiencing hair loss, spironolactone is growing in popularity as an off-label treatment of FPHL, though it is not FDA approved for this indication. Spironolactone is a synthetic steroid that has been used as a potassium-sparing diuretic for more than 60 years. Its primary metabolite, canrenone, competitively inhibits aldosterone.³⁷ It is FDA approved for the treatment of essential hypertension (25–100 mg), congestive heart failure (25 mg), diuretic-induced hypokalemia (25–100 mg), and primary hyperaldosteronism (100–400 mg).^37,40 Spironolactone was serendipitously discovered to treat hirsutism, acne, and seborrhea associated with polycystic ovary syndrome.⁴¹

Androgens are well studied in male pattern hair loss, and their role in FPHL is now becoming evident, with new research supporting the role of spironolactone as a useful antiandrogen.^42,43 An Australian open-label trial randomized 80 women with biopsy-proven FPHL to receive either spironolactone 200 mg daily or cyproterone acetate, an antiandrogen used abroad, including in European countries, in conjunction with an oral contraceptive pill for premenopausal women.⁴² Spironolactone was found to be as effective as the alternate regimen, with 44% of patients experiencing hair regrowth, 44% experiencing no progression of hair loss, and only 12% experiencing continued hair loss.⁴⁴ Spironolactone used in combination with minoxidil has been shown to demonstrate greater efficacy when compared to spironolactone alone.⁴⁵ One observational study of 100 women with FPHL found that once-daily capsules of minoxidil 0.25 mg combined with once daily spironolactone 25 mg was a safe and effective treatment of FPHL.⁴⁴ Spironolactone also is considered safe and effective to treat FPHL in postmenopausal women by inhibiting the relative androgen excess.⁴⁶

The starting dose for spironolactone usually is 25 mg twice daily and increased by 50 mg daily up to 200 mg daily as tolerated. Furthermore, results should be monitored for at least 6 months to assess efficacy accurately.⁴⁷ Side effects include headache, decreased libido, menstrual irregularities, orthostatic hypotension, fatigue, and hyperkalemia. Although hyperkalemia is a known side effect of spironolactone, one study of 974 male and female participants receiving spironolactone found that only 0.72% of participants experienced mild hyperkalemia (5.1–6.0 mEq/L) with no patients experiencing moderate or severe hyperkalemia. Regardless, providers may consider checking potassium levels within 4 to 8 weeks of initiating treatment with spironolactone.⁴⁸ Other potential AEs include gynecomastia and feminization; therefore, it is not recommended for use in men.⁴² Oral contraception is recommended to prevent pregnancy in premenopausal women, as spironolactone may cause feminization of the male fetus. Because of the antiandrogenic and progestogenic effects of spironolactone, there has been a theoretical concern for risk of inducing breast cancer, especially in postmenopausal women. However, a study conducted in the United Kingdom of more than 1 million female patients older than 55 years found that there was no increased risk of breast cancer in postmenopausal women.⁴⁹

Low-Level Laser Light Therapy

Low-level laser light therapy has been used to reduce pain, treat edema, and promote would healing for almost 50 years and is now one of the few FDA-cleared devices to treat alopecia. Low-level laser light therapy uses red beam or near-infrared nonthermal lasers at a wavelength of 600 to 1000 nm and from 5 to 500 mW. The exact mechanism of hair growth stimulation is not known; however, it is believed that LLLT accelerates mitosis, stimulates hair follicle stem cells to activate follicular keratinocytes, and alters cellular metabolism by inhibiting nitric oxide from cytochrome c oxidase.⁵⁰

Trials evaluating the efficacy of LLLT laser combs for the treatment of AGA have demonstrated notable improvements in hair density. For example, one sham device–controlled, double-blind clinical trial randomized 334 men and women to treatment with either an FDA-cleared laser comb vs sham devices.⁵¹ The treatment devices were used 3 times weekly for 26 weeks. Hair counts for those treated with the 7-, 9-, and 12-beam LLLT laser combs were significantly higher than the sham after 26 weeks (P<.05), without any serious AEs being reported.⁵¹ Another study in men with AGA proved similarly efficacious results using at-home LLLT therapy of 655 nm to the scalp every other day for 16 weeks (60 treatments).⁵² However, a 24-week randomized, double-blind, sham device–controlled, multicenter trial evaluating the LLLT helmet (combining 650-nm laser with 630- and 660-nm light-emitting diodes) among male and female patients with AGA failed to show promising results. Although mean (SD) hair thickness (12.6 [9.4] in LLLT group vs 3.9 [7.3] in control group [P=.01]) and hair density (17.2 [12.1] in LLLT group vs –2.1 [18.3] in control group [P=.003]) increased significantly, there was no significant difference in subject assessment of global appearance between the 2 groups.⁵³

Low-level laser light therapy devices are available both for use at home and in office, with 650- to 900-nm wavelengths at 5 mW being the recommended dose for men and women.⁵¹ With regard to AEs, the safety profile for LLLT is relatively favorable. Adverse events can include dry skin, pruritus, scalp tenderness, irritation, and a warm sensation at the treatment site.⁵²

Platelet-Rich Plasma

Originally used in the orthopedic literature to stimulate collagen growth, PRP has since been used in dermatology to promote hair regrowth by releasing platelet-derived growth factors, vascular endothelial growth factor, epidermal growth factor, insulinlike growth factor, and fibroblast growth factors to stimulate vascularization to the dermal papillary cells.^54,55 Platelet-rich plasma is derived from the supernatant of centrifuged whole blood and then injected in the dermis of the scalp to stimulate hair growth.

Although use of PRP is not approved or cleared by the FDA for treatment of hair loss, several studies have demonstrated the efficacy of autologous PRP use for treating AGA.⁵⁶ One pilot study of 19 male and female participants given a total of 5 PRP injections monthly for 3 months and subsequently at months 4 and 7 found a statistically significant improvement in mean hair density, hair diameter, and terminal-vellus hair ratio at 1-year follow-up (P<.05). Furthermore, histomorphometric evaluation demonstrated a decrease in perivascular inflammatory infiltrate.⁵⁷ On the other hand, 2 separate studies failed to show statistically significant improvements in hair growth after use of PRP.^58,59 Varying levels of success may be due in part to lack of a standard protocol for performing PRP injections. Studies comparing efficacy of different PRP administration regimens are emerging. A trial of 40 men and women found that subdermal PRP injections administered 3 times per month with booster injections administered 3 months later was more effective than other injection regimens, including once monthly injections.^58,59 Activators such as collagen, thrombin, 10% calcium chloride, and calcium gluconate may be added to the PRP serum to promote further growth factor secretion upon platelet activation.⁶⁰ However, different means of activation are used in different trials, potentially leading to varying results in clinical trials, with no one proven superior method.^61-63 The main drawback of PRP use is that there is no consensus regarding exact concentration, utility of activators, dosing parameters, depth of injection, or frequency of sessions.⁶⁰ Transient pain and erythema are the most common side effects of PRP injections, with no major AEs reported in the literature.⁶⁴

Microneedling

Microneedling is a minimally invasive procedure that uses needles to puncture the stratum corneum of the skin.⁶⁵ It was first used cosmetically more than 20 years ago due to its ability to increase collagen and elastin formation.⁵¹ Since its discovery, microneedling has been used to reduce the appearance of scars; augment transdermal drug delivery; and treat active acne vulgaris, melasma, hyperhidrosis, and alopecia.⁶⁵ Although there are numerous at-home and professional microneedling devices on the market, only one device has been FDA cleared thus far.

Microneedling is proposed to increase hair regrowth by triggering the wound healing response, which ultimately augments the release of platelet-derived and epidermal growth factors while also activating the hair bulge.⁶⁶ Treatment often is performed with a roller instrument that uses needles 0.5- to 2.5-mm long. Topical anesthetic cream may be applied prior to treatment.⁶⁷ The treated area is then washed and an antibiotic ointment is applied.⁵⁵ Management regimens typically require daily to weekly treatments with a total of 12 to 28 weeks to demonstrate an effect.

Microneedling has demonstrated efficacy in the treatment of hair loss, especially when combined with minoxidil. One study randomized 68 patients to undergo microneedling with minoxidil solution 5% twice daily compared to a control group of minoxidil solution 5% twice daily alone. After 12 weeks, patients treated with microneedling and minoxidil had significantly higher hair counts than the control group (P<.05).⁶⁸ It is speculated that microneedling increases penetration of topical medications, including minoxidil across the skin barrier, thereby enhancing absorption of large molecules.⁶⁶

Topical PRP has been used synergistically to augment the effects of microneedling. A trial randomized 93 patients with alopecia to receive minoxidil solution 5% alone, minoxidil solution 5% plus PRP, or microneedling with PRP.⁶⁹ Hair growth was appreciated in 26 of 31 patients treated with microneedling and PRP compared to 10 of 31 and 17 of 31 in the other 2 groups, respectively. However, when hair growth occurred in the minoxidil-treated group, it occurred faster, with changes in hair growth at 12 weeks compared to 26 weeks in the microneedling group.⁶⁹ When evaluating the efficacy of microneedling and PRP, it must be noted that there is no established leading protocol for treating hair loss, which may affect the success of the treatment.

The reported side-effect profile for microneedling and PRP injections has been favorable without any major AEs noted in clinical trials.^56,64,70 The possibility of bleeding, pain, erythema, and infection should be discussed with the patient nonetheless. More severe side effects such as allergic granulomatous reactions have been reported in the literature with the use of microneedling for facial rejuvenation.⁷¹

Stem Cells

Stem cell hair therapy is a new and promising area of research with the potential to treat alopecia. Although not yet FDA approved for this indication, human umbilical cord blood–derived mesenchymal stem cells (HUCB-MSCs) have received particular attention due to their proposed ability to promote tissue differentiation and repair, to replace aged and damaged hair cells, and to promote secretion of multiple growth factors.⁷² More recently, HUCB-MSCs have been shown to successfully differentiate into human hair follicles in vitro after 3 weeks of cell culture, establishing a method for high-speed and high-purity hair follicle cell differentiation with the hope of future injections to affected areas with hair loss.⁷³ Another study found that HUCB-MSCs enhanced growth of human follicular stem cells in vitro; the authors proposed an altered Wnt/β‐catenin and JAK/STAT pathway was responsible for improved growth of hair follicular cells.⁷⁴

Although umbilical cord blood is replete with the most rapidly dividing stem cells, autologous stem cells derived from the hair follicle or mononuclear cells also may be used to treat alopecia. One recent study randomized 40 patients with AGA and alopecia areata to receive 1 session of either autologous hair follicle or mononuclear cell–derived stem cell injections to the scalp.⁷⁵ Mononuclear cells were acquired from the upper iliac crest bone marrow of patients who were treated with granulocyte colony-stimulating factor 3 days prior to the procedure. Follicular stem cells were taken from 4-mm punch biopsies of the unaffected scalp. After 6 months, there was a notable improvement in hair growth confirmed by immunostaining and dermoscopy, without a significant difference between the forms of autologous stem cell source. Of note, 45% of study patients with alopecia areata showed recurrence of disease at 1-year follow-up. The most common AEs were scalp dermatitis in 20% of participants. Participants who underwent bone marrow biopsy experienced bone pain, hematoma, and granulocyte colony-stimulating factor–induced fatigue and chills.⁷⁵

Furthermore, the cost of stem cell therapy may be prohibitive. Therefore, although stem cell therapy is a novel and promising treatment for hair loss, future research is necessary to establish safety, efficacy, best practices, and accessibility.

Supplements

Patients failing routine treatments for alopecia may turn to holistic therapies. Nutrafol (Nutraceutical Wellness Inc), a novel nutraceutical product, is one such option that has been described for its anti-inflammatory, adaptogenic, antioxidant, and DHT-inhibiting properties. This supplement is not FDA approved or cleared, and large-scale clinical trials are lacking; however, one randomized controlled trial of 40 women with self-reported hair loss found a statistically significant increase in the number of terminal and vellus hair based on phototrichograms performed after 90 and 180 days (P=.009), with no AEs reported. This study, however, was limited by a small sample size.⁷⁶

Lamdapil (ISDIN) is another oral supplement being investigated for hair loss. It contains L-cystine amino acids; zinc; vitamins B₃, B₅, B₆; biotin; and the plant extract Serenoa repens.⁷¹Serenoa repens has reported activity inhibiting the enzyme 5α-reductase with the other vitamins, and amino acids are thought to maintain keratin and collagen growth in normal hair.⁷⁷ One randomized trial investigated use of Lamdapil capsules in a total of 70 patients, which included men with AGA and women experiencing telogen effluvium. For men, the anagen-telogen ratio increased in the Lamdapil-treated group by 23.4%, indicating that more hair was in the growing phase compared to placebo (P<.05). Women with telogen effluvium experienced a significantly greater improvement in the hair-pull test compared to placebo (P<.05).⁷⁷

Marine-derived nutraceutical substances also have been investigated for their role in treating hair loss. Viviscal, originally marketed under the name Hairgain, is one such supplement, which was shown to significantly reduce hair shedding at 3 and 6 months in a group of 96 premenopausal women diagnosed with subclinical hair thinning (P<.05). Additionally, phototrichogram images demonstrated a statistically significant increase in the mean velluslike hair diameter at 6 months compared to baseline.⁷⁸

Although nutraceutical products are not first-line therapy for hair loss, dermatologists may recommend these treatments in patients refusing prescription medications, specifically requesting a natural treatment, or in addition to a first-line agent such as minoxidil. It must be noted, however, that both supplements are new, and there is need for further investigation on their efficacy, safety, and dosing, as neither is FDA regulated.

Conclusion

Hair loss affects millions of Americans each year and has detrimental effects on self-esteem and psychosocial functioning. Nonsurgical treatment options will undoubtedly continue to intrigue patients, as they are often less costly and do not carry risks associated with surgery. Minoxidil, finasteride, and LLLT remain staples of therapy, with the strongest evidence supporting their safety and efficacy. Numerous other treatment options are emerging, including PRP, microneedling, mesenchymal and autologous stem cell therapy, and oral supplements, though further research must be conducted to establish dosing, safety, and best practices. Physicians must discuss patient preference and anticipated length of treatment when discussing alopecia treatment to maximize patient satisfaction.

The Diagnosis: Cutaneous B-Cell Lymphoma, Follicle Center Subtype 

A 4-mm punch biopsy through the center of the largest lesion on the right posterior shoulder demonstrated a superficial and deep dermal atypical lymphoid infiltrate composed predominantly of small mature lymphocytes with interspersed intermediate-sized cells with irregular to cleaved nuclei, dispersed chromatin, one or more distinct nucleoli, occasional mitoses, and small amounts of cytoplasm (Figure, A). Immunoperoxidase studies showed the infiltrate to be a mixture of CD3+ T cells and CD20+ B cells (Figure, B). The B cells coexpressed B-cell lymphoma (Bcl) 6 protein (Figure, C) but were negative for multiple myeloma 1/interferon regulatory factor 4 and CD10; Bcl2 protein was positive in T cells but inconclusive for staining in B cells. Very few plasma cells were seen with CD138 stain. Fluorescence in situ hybridization studies were negative for IgH and BCL2 gene rearrangement. Molecular diagnostic studies for IgH and κ light chain gene rearrangement were positive for a clonal population. A clonal T-cell receptor γ chain gene rearrangement was not identified. The overall morphologic, immunophenotypic, and molecular findings were consistent with cutaneous involvement by a B-cell lymphoproliferative disorder, favoring primary cutaneous follicle center lymphoma (PCFCL). 

The patient was referred to our cancer center for further workup consisting of a complete blood cell count with differential; comprehensive metabolic panel; lactate dehydrogenase; serum protein electrophoresis; peripheral blood flow cytometry; and computed tomography of the chest, abdomen, and pelvis. The analysis was unremarkable, supporting primary cutaneous disease. Additional studies suggested in the National Comprehensive Cancer Network (NCCN) Guidelines for primary cutaneous B-cell lymphomas include hepatitis B testing if the patient is being considered for immunotherapy and/or chemotherapy due to risk of reactivation, pregnancy testing in women of childbearing age, and human immunodeficiency virus testing.¹ These tests were not performed in our patient because he did not have any risk factors for hepatitis B or human immunodeficiency virus. 

Primary cutaneous B-cell lymphomas originate in the skin without evidence of extracutaneous disease at presentation. They account for approximately 25% of primary cutaneous lymphomas in the United States, with primary cutaneous T-cell lymphoma being most common.² The revised 2017 World Health Organization classification system defines 3 major subtypes of primary cutaneous B-cell lymphoma (Table).^3-9 Primary cutaneous follicle center lymphoma is the most common subtype, accounting for approximately 60% of cases. In Europe, an association with Borrelia burgdorferi has been reported.¹⁰ The extent of skin involvement determines the T portion of TNM staging for PCFCL. It is based on the size and location of affected body regions that are delineated, such as the head and neck, chest, abdomen/genitalia, upper back, lower back/buttocks, each upper arm, each lower arm/hand, each upper leg, and each lower leg/foot. T1 is for solitary skin involvement in which the lesion is 5 cm or less in diameter (T1a) or greater than 5 cm (T1b). T2 is for regional skin involvement limited to 1 or 2 contiguous body regions, whereas T2a has all lesions confined to an area 15 cm or less in diameter, T2b has lesions confined to an area greater than 15 cm up to 30 cm in diameter, and the area for T2c is greater than 30 cm in diameter. Finally, T3 is generalized skin involvement, whereas T3a has multiple lesions in 2 noncontiguous body regions, and T3b has multiple lesions on 3 or more regions.¹¹ At presentation, our patient was considered T2cN0M0, as his lesions were present on only 2 contiguous regions extending beyond 30 cm without any evidence of lymph node involvement or metastasis.  

Treatment of PCFCL is tailored to each case, as there is a paucity of randomized data in this rare entity. It is guided by the number and location of cutaneous lesions, associated skin symptoms, age of the patient, and performance status. Local disease can be treated with intralesional corticosteroids, excision, or close monitoring if the patient is asymptomatic. Low-dose radiation therapy may be used as primary treatment or for local recurrence.¹² Patients with more extensive skin lesions can relapse after clearing; those with refractory disease can be managed with single-agent rituximab.¹³ Our patient underwent low-dose radiation therapy with good response and has not experienced recurrence. 

Lymphocytoma cutis, also known as benign reactive lymphoid hyperplasia, can be idiopathic or can arise after arthropod assault, penetrative skin trauma, drugs, or infections. In granuloma annulare, small dermal papules may present in isolation or coalesce to form annular plaques. It is a benign inflammatory disorder of unknown cause, can have mild pruritus, and usually is self-limited. Pyogenic granuloma is a benign vascular proliferation of unknown etiology. Sarcoidosis is an immune-mediated systemic disorder with granuloma formation that has a predilection for the lungs and the skin. 

The Diagnosis: Cutaneous B-Cell Lymphoma, Follicle Center Subtype 

A 4-mm punch biopsy through the center of the largest lesion on the right posterior shoulder demonstrated a superficial and deep dermal atypical lymphoid infiltrate composed predominantly of small mature lymphocytes with interspersed intermediate-sized cells with irregular to cleaved nuclei, dispersed chromatin, one or more distinct nucleoli, occasional mitoses, and small amounts of cytoplasm (Figure, A). Immunoperoxidase studies showed the infiltrate to be a mixture of CD3+ T cells and CD20+ B cells (Figure, B). The B cells coexpressed B-cell lymphoma (Bcl) 6 protein (Figure, C) but were negative for multiple myeloma 1/interferon regulatory factor 4 and CD10; Bcl2 protein was positive in T cells but inconclusive for staining in B cells. Very few plasma cells were seen with CD138 stain. Fluorescence in situ hybridization studies were negative for IgH and BCL2 gene rearrangement. Molecular diagnostic studies for IgH and κ light chain gene rearrangement were positive for a clonal population. A clonal T-cell receptor γ chain gene rearrangement was not identified. The overall morphologic, immunophenotypic, and molecular findings were consistent with cutaneous involvement by a B-cell lymphoproliferative disorder, favoring primary cutaneous follicle center lymphoma (PCFCL). 

The patient was referred to our cancer center for further workup consisting of a complete blood cell count with differential; comprehensive metabolic panel; lactate dehydrogenase; serum protein electrophoresis; peripheral blood flow cytometry; and computed tomography of the chest, abdomen, and pelvis. The analysis was unremarkable, supporting primary cutaneous disease. Additional studies suggested in the National Comprehensive Cancer Network (NCCN) Guidelines for primary cutaneous B-cell lymphomas include hepatitis B testing if the patient is being considered for immunotherapy and/or chemotherapy due to risk of reactivation, pregnancy testing in women of childbearing age, and human immunodeficiency virus testing.¹ These tests were not performed in our patient because he did not have any risk factors for hepatitis B or human immunodeficiency virus. 

Primary cutaneous B-cell lymphomas originate in the skin without evidence of extracutaneous disease at presentation. They account for approximately 25% of primary cutaneous lymphomas in the United States, with primary cutaneous T-cell lymphoma being most common.² The revised 2017 World Health Organization classification system defines 3 major subtypes of primary cutaneous B-cell lymphoma (Table).^3-9 Primary cutaneous follicle center lymphoma is the most common subtype, accounting for approximately 60% of cases. In Europe, an association with Borrelia burgdorferi has been reported.¹⁰ The extent of skin involvement determines the T portion of TNM staging for PCFCL. It is based on the size and location of affected body regions that are delineated, such as the head and neck, chest, abdomen/genitalia, upper back, lower back/buttocks, each upper arm, each lower arm/hand, each upper leg, and each lower leg/foot. T1 is for solitary skin involvement in which the lesion is 5 cm or less in diameter (T1a) or greater than 5 cm (T1b). T2 is for regional skin involvement limited to 1 or 2 contiguous body regions, whereas T2a has all lesions confined to an area 15 cm or less in diameter, T2b has lesions confined to an area greater than 15 cm up to 30 cm in diameter, and the area for T2c is greater than 30 cm in diameter. Finally, T3 is generalized skin involvement, whereas T3a has multiple lesions in 2 noncontiguous body regions, and T3b has multiple lesions on 3 or more regions.¹¹ At presentation, our patient was considered T2cN0M0, as his lesions were present on only 2 contiguous regions extending beyond 30 cm without any evidence of lymph node involvement or metastasis.  

Treatment of PCFCL is tailored to each case, as there is a paucity of randomized data in this rare entity. It is guided by the number and location of cutaneous lesions, associated skin symptoms, age of the patient, and performance status. Local disease can be treated with intralesional corticosteroids, excision, or close monitoring if the patient is asymptomatic. Low-dose radiation therapy may be used as primary treatment or for local recurrence.¹² Patients with more extensive skin lesions can relapse after clearing; those with refractory disease can be managed with single-agent rituximab.¹³ Our patient underwent low-dose radiation therapy with good response and has not experienced recurrence. 

Lymphocytoma cutis, also known as benign reactive lymphoid hyperplasia, can be idiopathic or can arise after arthropod assault, penetrative skin trauma, drugs, or infections. In granuloma annulare, small dermal papules may present in isolation or coalesce to form annular plaques. It is a benign inflammatory disorder of unknown cause, can have mild pruritus, and usually is self-limited. Pyogenic granuloma is a benign vascular proliferation of unknown etiology. Sarcoidosis is an immune-mediated systemic disorder with granuloma formation that has a predilection for the lungs and the skin. 

The Diagnosis: Cutaneous B-Cell Lymphoma, Follicle Center Subtype 

A 4-mm punch biopsy through the center of the largest lesion on the right posterior shoulder demonstrated a superficial and deep dermal atypical lymphoid infiltrate composed predominantly of small mature lymphocytes with interspersed intermediate-sized cells with irregular to cleaved nuclei, dispersed chromatin, one or more distinct nucleoli, occasional mitoses, and small amounts of cytoplasm (Figure, A). Immunoperoxidase studies showed the infiltrate to be a mixture of CD3+ T cells and CD20+ B cells (Figure, B). The B cells coexpressed B-cell lymphoma (Bcl) 6 protein (Figure, C) but were negative for multiple myeloma 1/interferon regulatory factor 4 and CD10; Bcl2 protein was positive in T cells but inconclusive for staining in B cells. Very few plasma cells were seen with CD138 stain. Fluorescence in situ hybridization studies were negative for IgH and BCL2 gene rearrangement. Molecular diagnostic studies for IgH and κ light chain gene rearrangement were positive for a clonal population. A clonal T-cell receptor γ chain gene rearrangement was not identified. The overall morphologic, immunophenotypic, and molecular findings were consistent with cutaneous involvement by a B-cell lymphoproliferative disorder, favoring primary cutaneous follicle center lymphoma (PCFCL). 

The patient was referred to our cancer center for further workup consisting of a complete blood cell count with differential; comprehensive metabolic panel; lactate dehydrogenase; serum protein electrophoresis; peripheral blood flow cytometry; and computed tomography of the chest, abdomen, and pelvis. The analysis was unremarkable, supporting primary cutaneous disease. Additional studies suggested in the National Comprehensive Cancer Network (NCCN) Guidelines for primary cutaneous B-cell lymphomas include hepatitis B testing if the patient is being considered for immunotherapy and/or chemotherapy due to risk of reactivation, pregnancy testing in women of childbearing age, and human immunodeficiency virus testing.¹ These tests were not performed in our patient because he did not have any risk factors for hepatitis B or human immunodeficiency virus. 

Primary cutaneous B-cell lymphomas originate in the skin without evidence of extracutaneous disease at presentation. They account for approximately 25% of primary cutaneous lymphomas in the United States, with primary cutaneous T-cell lymphoma being most common.² The revised 2017 World Health Organization classification system defines 3 major subtypes of primary cutaneous B-cell lymphoma (Table).^3-9 Primary cutaneous follicle center lymphoma is the most common subtype, accounting for approximately 60% of cases. In Europe, an association with Borrelia burgdorferi has been reported.¹⁰ The extent of skin involvement determines the T portion of TNM staging for PCFCL. It is based on the size and location of affected body regions that are delineated, such as the head and neck, chest, abdomen/genitalia, upper back, lower back/buttocks, each upper arm, each lower arm/hand, each upper leg, and each lower leg/foot. T1 is for solitary skin involvement in which the lesion is 5 cm or less in diameter (T1a) or greater than 5 cm (T1b). T2 is for regional skin involvement limited to 1 or 2 contiguous body regions, whereas T2a has all lesions confined to an area 15 cm or less in diameter, T2b has lesions confined to an area greater than 15 cm up to 30 cm in diameter, and the area for T2c is greater than 30 cm in diameter. Finally, T3 is generalized skin involvement, whereas T3a has multiple lesions in 2 noncontiguous body regions, and T3b has multiple lesions on 3 or more regions.¹¹ At presentation, our patient was considered T2cN0M0, as his lesions were present on only 2 contiguous regions extending beyond 30 cm without any evidence of lymph node involvement or metastasis.  

Treatment of PCFCL is tailored to each case, as there is a paucity of randomized data in this rare entity. It is guided by the number and location of cutaneous lesions, associated skin symptoms, age of the patient, and performance status. Local disease can be treated with intralesional corticosteroids, excision, or close monitoring if the patient is asymptomatic. Low-dose radiation therapy may be used as primary treatment or for local recurrence.¹² Patients with more extensive skin lesions can relapse after clearing; those with refractory disease can be managed with single-agent rituximab.¹³ Our patient underwent low-dose radiation therapy with good response and has not experienced recurrence. 

Lymphocytoma cutis, also known as benign reactive lymphoid hyperplasia, can be idiopathic or can arise after arthropod assault, penetrative skin trauma, drugs, or infections. In granuloma annulare, small dermal papules may present in isolation or coalesce to form annular plaques. It is a benign inflammatory disorder of unknown cause, can have mild pruritus, and usually is self-limited. Pyogenic granuloma is a benign vascular proliferation of unknown etiology. Sarcoidosis is an immune-mediated systemic disorder with granuloma formation that has a predilection for the lungs and the skin. 

The Diagnosis: Atypical Fibroxanthoma  

Shave biopsy showed the superficial aspect of a highly cellular tumor composed of pleomorphic spindle cells exhibiting storiform growth and increased mitotic activity (Figure 1). The tumor stained positive for factor XIIIa, CD163, CD68, and smooth muscle actin (mild), and negative for high-molecular-weight cytokeratin (HMW-CK), p63, S-100, and melan-A. Subsequent excision with 0.5-cm margins was performed, and histopathology showed a well-circumscribed tumor contained within the dermis with a histologic scar at the outer margin (Figure 2). There was no lymphovascular or perineural invasion by tumor cells. Re-excision with 0.3-cm margins demonstrated no residual scar or tumor, and external radiation was deferred due to clear surgical margins.  

Atypical fibroxanthoma (AFX) belongs to a group of spindle cell neoplasms that can be diagnostically challenging, as they often lack specific morphologic features on examination or routine histology. These neoplasms--of which the differential includes malignant fibrous histiocytoma, spindle cell squamous cell carcinoma (SCC), desmoplastic melanoma, and leiomyosarcoma--may each appear as a rapidly enlarging solitary plaque or nodule on sun-damaged skin on the head and neck or less commonly on the trunk, arms, or legs. Histologically, the cells of AFX exhibit notable pleomorphism with frequent atypical mitotic figures and nonspecific surrounding dermal changes. Subcutaneous and lymphovascular or perineural invasion of tumor cells can point away from the diagnosis of AFX; however, these features are likely to be missed in small superficial shave biopsies.^1,2 Therefore, immunohistochemistry (IHC) and adequate tumor sampling are essential in the accurate diagnosis of AFX and other spindle cell neoplasms.  

Several IHC markers have been employed in differentiating AFX from other spindle cell neoplasms.^3-8 Positive stains for AFX include factor XIIIa (10%-25%), vimentin (>99%), CD10 (95%-100%), procollagen (87%), CD99 (35%-73%), CD163 (37%-79%), smooth muscle actin (50%), CD68 (>50%), and CD31 (43%). Other stains, such as HMW-CK, S-100, p63, desmin, CD34, and melan-A, typically are negative in AFX but are actively expressed in other pleomorphic spindle cell tumors. The Table summarizes the utility of these various markers in narrowing the differential diagnosis of a spindle cell lesion. Selection of an appropriate panel of IHC markers is critical for accurate diagnosis of AFX and exclusion of more aggressive, poorly differentiated spindle cell neoplasms. Key IHC markers include S-100 (negative in AFX; positive in desmoplastic melanoma), HMW-CK (negative in AFX; positive in spindle cell SCC), and p63 (negative in AFX; positive in spindle cell SCC). Benoit et al⁹ reported a case of a poorly differentiated spindle cell SCC misdiagnosed as AFX based on a limited IHC panel that was negative for pancytokeratin and S-100. Later, a more comprehensive IHC panel including HMW-CK and p63 confirmed spindle cell SCC, but by this time, a delay in therapy had allowed the tumor to metastasize, which ultimately proved fatal to the patient.⁹  

In addition to incomplete IHC evaluation, accurate diagnosis of spindle cell tumors also may be obscured by inadequate tumor sampling. The cells of AFX tumors often are well circumscribed and dermally based, and an excisional biopsy is the preferred biopsy procedure for AFX. A tumor invading into subcutaneous tissue or into lymphovascular or perineural structures suggests a more aggressive, poorly differentiated spindle cell neoplasm.^1,3 For example, the tumor cells of malignant fibrous histiocytoma, which belongs to the undifferentiated pleomorphic sarcoma group, may appear identical to those of AFX on histology, and the 2 tumors display similar IHC profiles.³ Malignant fibrous histiocytoma, however, extends into the subcutaneous space and portends a notably worse prognosis compared to AFX. Malignant fibrous histiocytoma tumors therefore require more aggressive treatment strategies such as external beam radiation therapy, whereas AFX can be safely treated with surgical removal alone. In our patient, complete visualization of tumor margins solidified the diagnosis of AFX and spared our patient from unnecessary radiation therapy. Overall, AFX has a good prognosis and metastasis is rare, particularly when good margin control is achieved.¹⁰ 

Our case highlights the importance of clinicopathologic correlation, including appropriate IHC analysis and adequate tumor sampling in the diagnostic workup of a pleomorphic spindle cell neoplasm. Although these tumors are well studied, their notable degree of clinical and histologic heterogeneity may pose a diagnostic challenge to even experienced dermatologists and require careful consideration of the potential pitfalls in diagnosis.  

The Diagnosis: Atypical Fibroxanthoma  

Shave biopsy showed the superficial aspect of a highly cellular tumor composed of pleomorphic spindle cells exhibiting storiform growth and increased mitotic activity (Figure 1). The tumor stained positive for factor XIIIa, CD163, CD68, and smooth muscle actin (mild), and negative for high-molecular-weight cytokeratin (HMW-CK), p63, S-100, and melan-A. Subsequent excision with 0.5-cm margins was performed, and histopathology showed a well-circumscribed tumor contained within the dermis with a histologic scar at the outer margin (Figure 2). There was no lymphovascular or perineural invasion by tumor cells. Re-excision with 0.3-cm margins demonstrated no residual scar or tumor, and external radiation was deferred due to clear surgical margins.  

Atypical fibroxanthoma (AFX) belongs to a group of spindle cell neoplasms that can be diagnostically challenging, as they often lack specific morphologic features on examination or routine histology. These neoplasms--of which the differential includes malignant fibrous histiocytoma, spindle cell squamous cell carcinoma (SCC), desmoplastic melanoma, and leiomyosarcoma--may each appear as a rapidly enlarging solitary plaque or nodule on sun-damaged skin on the head and neck or less commonly on the trunk, arms, or legs. Histologically, the cells of AFX exhibit notable pleomorphism with frequent atypical mitotic figures and nonspecific surrounding dermal changes. Subcutaneous and lymphovascular or perineural invasion of tumor cells can point away from the diagnosis of AFX; however, these features are likely to be missed in small superficial shave biopsies.^1,2 Therefore, immunohistochemistry (IHC) and adequate tumor sampling are essential in the accurate diagnosis of AFX and other spindle cell neoplasms.  

Several IHC markers have been employed in differentiating AFX from other spindle cell neoplasms.^3-8 Positive stains for AFX include factor XIIIa (10%-25%), vimentin (>99%), CD10 (95%-100%), procollagen (87%), CD99 (35%-73%), CD163 (37%-79%), smooth muscle actin (50%), CD68 (>50%), and CD31 (43%). Other stains, such as HMW-CK, S-100, p63, desmin, CD34, and melan-A, typically are negative in AFX but are actively expressed in other pleomorphic spindle cell tumors. The Table summarizes the utility of these various markers in narrowing the differential diagnosis of a spindle cell lesion. Selection of an appropriate panel of IHC markers is critical for accurate diagnosis of AFX and exclusion of more aggressive, poorly differentiated spindle cell neoplasms. Key IHC markers include S-100 (negative in AFX; positive in desmoplastic melanoma), HMW-CK (negative in AFX; positive in spindle cell SCC), and p63 (negative in AFX; positive in spindle cell SCC). Benoit et al⁹ reported a case of a poorly differentiated spindle cell SCC misdiagnosed as AFX based on a limited IHC panel that was negative for pancytokeratin and S-100. Later, a more comprehensive IHC panel including HMW-CK and p63 confirmed spindle cell SCC, but by this time, a delay in therapy had allowed the tumor to metastasize, which ultimately proved fatal to the patient.⁹  

In addition to incomplete IHC evaluation, accurate diagnosis of spindle cell tumors also may be obscured by inadequate tumor sampling. The cells of AFX tumors often are well circumscribed and dermally based, and an excisional biopsy is the preferred biopsy procedure for AFX. A tumor invading into subcutaneous tissue or into lymphovascular or perineural structures suggests a more aggressive, poorly differentiated spindle cell neoplasm.^1,3 For example, the tumor cells of malignant fibrous histiocytoma, which belongs to the undifferentiated pleomorphic sarcoma group, may appear identical to those of AFX on histology, and the 2 tumors display similar IHC profiles.³ Malignant fibrous histiocytoma, however, extends into the subcutaneous space and portends a notably worse prognosis compared to AFX. Malignant fibrous histiocytoma tumors therefore require more aggressive treatment strategies such as external beam radiation therapy, whereas AFX can be safely treated with surgical removal alone. In our patient, complete visualization of tumor margins solidified the diagnosis of AFX and spared our patient from unnecessary radiation therapy. Overall, AFX has a good prognosis and metastasis is rare, particularly when good margin control is achieved.¹⁰ 

Our case highlights the importance of clinicopathologic correlation, including appropriate IHC analysis and adequate tumor sampling in the diagnostic workup of a pleomorphic spindle cell neoplasm. Although these tumors are well studied, their notable degree of clinical and histologic heterogeneity may pose a diagnostic challenge to even experienced dermatologists and require careful consideration of the potential pitfalls in diagnosis.  

The Diagnosis: Atypical Fibroxanthoma  

Shave biopsy showed the superficial aspect of a highly cellular tumor composed of pleomorphic spindle cells exhibiting storiform growth and increased mitotic activity (Figure 1). The tumor stained positive for factor XIIIa, CD163, CD68, and smooth muscle actin (mild), and negative for high-molecular-weight cytokeratin (HMW-CK), p63, S-100, and melan-A. Subsequent excision with 0.5-cm margins was performed, and histopathology showed a well-circumscribed tumor contained within the dermis with a histologic scar at the outer margin (Figure 2). There was no lymphovascular or perineural invasion by tumor cells. Re-excision with 0.3-cm margins demonstrated no residual scar or tumor, and external radiation was deferred due to clear surgical margins.  

Atypical fibroxanthoma (AFX) belongs to a group of spindle cell neoplasms that can be diagnostically challenging, as they often lack specific morphologic features on examination or routine histology. These neoplasms--of which the differential includes malignant fibrous histiocytoma, spindle cell squamous cell carcinoma (SCC), desmoplastic melanoma, and leiomyosarcoma--may each appear as a rapidly enlarging solitary plaque or nodule on sun-damaged skin on the head and neck or less commonly on the trunk, arms, or legs. Histologically, the cells of AFX exhibit notable pleomorphism with frequent atypical mitotic figures and nonspecific surrounding dermal changes. Subcutaneous and lymphovascular or perineural invasion of tumor cells can point away from the diagnosis of AFX; however, these features are likely to be missed in small superficial shave biopsies.^1,2 Therefore, immunohistochemistry (IHC) and adequate tumor sampling are essential in the accurate diagnosis of AFX and other spindle cell neoplasms.  

Several IHC markers have been employed in differentiating AFX from other spindle cell neoplasms.^3-8 Positive stains for AFX include factor XIIIa (10%-25%), vimentin (>99%), CD10 (95%-100%), procollagen (87%), CD99 (35%-73%), CD163 (37%-79%), smooth muscle actin (50%), CD68 (>50%), and CD31 (43%). Other stains, such as HMW-CK, S-100, p63, desmin, CD34, and melan-A, typically are negative in AFX but are actively expressed in other pleomorphic spindle cell tumors. The Table summarizes the utility of these various markers in narrowing the differential diagnosis of a spindle cell lesion. Selection of an appropriate panel of IHC markers is critical for accurate diagnosis of AFX and exclusion of more aggressive, poorly differentiated spindle cell neoplasms. Key IHC markers include S-100 (negative in AFX; positive in desmoplastic melanoma), HMW-CK (negative in AFX; positive in spindle cell SCC), and p63 (negative in AFX; positive in spindle cell SCC). Benoit et al⁹ reported a case of a poorly differentiated spindle cell SCC misdiagnosed as AFX based on a limited IHC panel that was negative for pancytokeratin and S-100. Later, a more comprehensive IHC panel including HMW-CK and p63 confirmed spindle cell SCC, but by this time, a delay in therapy had allowed the tumor to metastasize, which ultimately proved fatal to the patient.⁹  

In addition to incomplete IHC evaluation, accurate diagnosis of spindle cell tumors also may be obscured by inadequate tumor sampling. The cells of AFX tumors often are well circumscribed and dermally based, and an excisional biopsy is the preferred biopsy procedure for AFX. A tumor invading into subcutaneous tissue or into lymphovascular or perineural structures suggests a more aggressive, poorly differentiated spindle cell neoplasm.^1,3 For example, the tumor cells of malignant fibrous histiocytoma, which belongs to the undifferentiated pleomorphic sarcoma group, may appear identical to those of AFX on histology, and the 2 tumors display similar IHC profiles.³ Malignant fibrous histiocytoma, however, extends into the subcutaneous space and portends a notably worse prognosis compared to AFX. Malignant fibrous histiocytoma tumors therefore require more aggressive treatment strategies such as external beam radiation therapy, whereas AFX can be safely treated with surgical removal alone. In our patient, complete visualization of tumor margins solidified the diagnosis of AFX and spared our patient from unnecessary radiation therapy. Overall, AFX has a good prognosis and metastasis is rare, particularly when good margin control is achieved.¹⁰ 

Our case highlights the importance of clinicopathologic correlation, including appropriate IHC analysis and adequate tumor sampling in the diagnostic workup of a pleomorphic spindle cell neoplasm. Although these tumors are well studied, their notable degree of clinical and histologic heterogeneity may pose a diagnostic challenge to even experienced dermatologists and require careful consideration of the potential pitfalls in diagnosis.  

To the Editor:

Acne fulminans (AF), the most severe form of acne, is a rare condition with an incidence of less than 1% of total acne cases.¹ Adolescent boys are the most susceptible group of patients.² Painful inflammatory pustules that transform into deep ulcerations covered by abundant hemorrhagic crust are typical of AF. Commonly affected areas include the face, back, neck, and chest. Additionally, fever and polyarthralgia may be present, and there often is myopathy due to rapid weight loss.^3,4 Less often, erythema nodosum and splenomegaly may be observed.⁵ Laboratory testing also may reveal markers of systemic inflammation such as leukocytosis with neutrophilia, elevated C-reactive protein levels, increased erythrocyte sedimentation rate, and thrombocytosis. Anemia and elevated hepatic enzyme levels also may be present in AF.² It is suspected that AF may be induced by low doses of isotretinoin therapy with concomitant inherited susceptibility.⁶

We report the case of a 21-year-old man who was referred to the Department of Dermatology by his primary care physician for evaluation of severe hemorrhagic lesions on the trunk following use of oral isotretinoin (Figure 1). Prior to development of the lesions, the patient had started weekly intramuscular injections of testosterone 500 mg, which he purchased online without consulting a physician, to address muscle mass reduction associated with sudden weight loss from intense physical training. After 8 months of testosterone supplementation along with continued physical training, the patient presented to his primary care physician for treatment of acne vulgaris on the back and trunk of 2 months’ duration. Oral isotretinoin 20 mg once daily was initiated; however, the patient reported that the acne lesions showed progression after 1 month of treatment. Isotretinoin was increased to a more weight-appropriate dosage of 60 mg once daily 2 weeks before admission to our dermatology clinic.

Treatment initially included cessation of isotretinoin and administration of prednisone, omeprazole, clindamycin, and doxycycline. Prednisone was given at a dosage of 40 mg once daily for 1 week, then decreased by 5 mg every 7 days. Omeprazole was given concurrently as prophylaxis for the gastrointestinal tract side effects of long-term prednisone use. Clindamycin was given at a dosage of 300 mg 3 times daily. Doxycycline was given for 6 weeks at a dosage of 100 mg twice daily. Topical octenidine dihydrochloride also was given.

The clinical diagnosis in our patient also was supported by the hypothesis that heredity, overactive immune reactions, bacterial infections, and use of some drugs (eg, isotretinoin, tetracycline, testosterone) can trigger AF.⁸ The most well-known theory is that low doses of isotretinoin induce AF.⁶ The majority of cases are caused by doses of less than 20 mg/kg once daily, but there have been reports of patients using full doses and developing this condition.⁹ The fact that the use of low- and high-dose isotretinoin can provoke AF suggests an idiosyncratic reaction that is not clearly dose related. The most dangerous triggering factor of AF is concomitant usage of testosterone and isotretinoin.¹⁰ Our patient used testosterone injections to increase muscle mass and underwent treatment with isotretinoin for acne.

Treatment of AF is controversial, as there is no standard therapy. Currently, steroids and isotretinoin are the treatments of choice. Antibiotic use is controversial because of a lack of randomized trials.¹¹

In the first stage of treatment, prednisone 0.5 to 1 mg/kg once daily is recommended as an initial anti-inflammatory therapy, with gradual dose reduction. According to evidence-based recommendations, a low dose of isotretinoin can be introduced after crusted lesions have healed. The overlapping therapy with steroids and isotretinoin should be provided for at least 4 weeks. High-potency topical corticosteroids can be used on granulation tissue, which can shorten the systemic treatment with prednisone or can be an alternative treatment for patients with contraindications to systemic corticosteroids.¹¹

Additionally, local care of the lesions including compresses and topical emollients is crucial. There are some case reports in which there is introduction of high doses of isotretinoin, subsequently with systemic steroids.^7,8,12 Seukeran and Cunliffe⁵ proved that it is beneficial to give acne prophylaxis to prevent further episodes. Our patient was similarly treated with systemic steroids and isotretinoin. Treatment guidelines for AF do not recommend oral antibiotics,¹¹ but data are limited in the case of isotretinoin-induced AF. Our patient was given doxycycline concomitant with systemic steroids, which was necessary due to signs of secondary infection from a lesion culture. Doxycycline was stopped when isotretinoin treatment was initiated to prevent pseudotumor cerebri. The patient achieved good clinical improvement with no relapse.

Using isotretinoin to treat acne vulgaris has many benefits, despite the possibility of developing AF as an extremely rare complication. Clinicians should be aware of the risk of this complication to make the diagnosis and provide appropriate care, especially in young men. It is particularly important to consider the possibility of concomitant testosterone and isotretinoin when documenting the patient’s medical history.

To the Editor:

Acne fulminans (AF), the most severe form of acne, is a rare condition with an incidence of less than 1% of total acne cases.¹ Adolescent boys are the most susceptible group of patients.² Painful inflammatory pustules that transform into deep ulcerations covered by abundant hemorrhagic crust are typical of AF. Commonly affected areas include the face, back, neck, and chest. Additionally, fever and polyarthralgia may be present, and there often is myopathy due to rapid weight loss.^3,4 Less often, erythema nodosum and splenomegaly may be observed.⁵ Laboratory testing also may reveal markers of systemic inflammation such as leukocytosis with neutrophilia, elevated C-reactive protein levels, increased erythrocyte sedimentation rate, and thrombocytosis. Anemia and elevated hepatic enzyme levels also may be present in AF.² It is suspected that AF may be induced by low doses of isotretinoin therapy with concomitant inherited susceptibility.⁶

We report the case of a 21-year-old man who was referred to the Department of Dermatology by his primary care physician for evaluation of severe hemorrhagic lesions on the trunk following use of oral isotretinoin (Figure 1). Prior to development of the lesions, the patient had started weekly intramuscular injections of testosterone 500 mg, which he purchased online without consulting a physician, to address muscle mass reduction associated with sudden weight loss from intense physical training. After 8 months of testosterone supplementation along with continued physical training, the patient presented to his primary care physician for treatment of acne vulgaris on the back and trunk of 2 months’ duration. Oral isotretinoin 20 mg once daily was initiated; however, the patient reported that the acne lesions showed progression after 1 month of treatment. Isotretinoin was increased to a more weight-appropriate dosage of 60 mg once daily 2 weeks before admission to our dermatology clinic.

Treatment initially included cessation of isotretinoin and administration of prednisone, omeprazole, clindamycin, and doxycycline. Prednisone was given at a dosage of 40 mg once daily for 1 week, then decreased by 5 mg every 7 days. Omeprazole was given concurrently as prophylaxis for the gastrointestinal tract side effects of long-term prednisone use. Clindamycin was given at a dosage of 300 mg 3 times daily. Doxycycline was given for 6 weeks at a dosage of 100 mg twice daily. Topical octenidine dihydrochloride also was given.

The clinical diagnosis in our patient also was supported by the hypothesis that heredity, overactive immune reactions, bacterial infections, and use of some drugs (eg, isotretinoin, tetracycline, testosterone) can trigger AF.⁸ The most well-known theory is that low doses of isotretinoin induce AF.⁶ The majority of cases are caused by doses of less than 20 mg/kg once daily, but there have been reports of patients using full doses and developing this condition.⁹ The fact that the use of low- and high-dose isotretinoin can provoke AF suggests an idiosyncratic reaction that is not clearly dose related. The most dangerous triggering factor of AF is concomitant usage of testosterone and isotretinoin.¹⁰ Our patient used testosterone injections to increase muscle mass and underwent treatment with isotretinoin for acne.

Treatment of AF is controversial, as there is no standard therapy. Currently, steroids and isotretinoin are the treatments of choice. Antibiotic use is controversial because of a lack of randomized trials.¹¹

In the first stage of treatment, prednisone 0.5 to 1 mg/kg once daily is recommended as an initial anti-inflammatory therapy, with gradual dose reduction. According to evidence-based recommendations, a low dose of isotretinoin can be introduced after crusted lesions have healed. The overlapping therapy with steroids and isotretinoin should be provided for at least 4 weeks. High-potency topical corticosteroids can be used on granulation tissue, which can shorten the systemic treatment with prednisone or can be an alternative treatment for patients with contraindications to systemic corticosteroids.¹¹

Additionally, local care of the lesions including compresses and topical emollients is crucial. There are some case reports in which there is introduction of high doses of isotretinoin, subsequently with systemic steroids.^7,8,12 Seukeran and Cunliffe⁵ proved that it is beneficial to give acne prophylaxis to prevent further episodes. Our patient was similarly treated with systemic steroids and isotretinoin. Treatment guidelines for AF do not recommend oral antibiotics,¹¹ but data are limited in the case of isotretinoin-induced AF. Our patient was given doxycycline concomitant with systemic steroids, which was necessary due to signs of secondary infection from a lesion culture. Doxycycline was stopped when isotretinoin treatment was initiated to prevent pseudotumor cerebri. The patient achieved good clinical improvement with no relapse.

Using isotretinoin to treat acne vulgaris has many benefits, despite the possibility of developing AF as an extremely rare complication. Clinicians should be aware of the risk of this complication to make the diagnosis and provide appropriate care, especially in young men. It is particularly important to consider the possibility of concomitant testosterone and isotretinoin when documenting the patient’s medical history.

To the Editor:

Acne fulminans (AF), the most severe form of acne, is a rare condition with an incidence of less than 1% of total acne cases.¹ Adolescent boys are the most susceptible group of patients.² Painful inflammatory pustules that transform into deep ulcerations covered by abundant hemorrhagic crust are typical of AF. Commonly affected areas include the face, back, neck, and chest. Additionally, fever and polyarthralgia may be present, and there often is myopathy due to rapid weight loss.^3,4 Less often, erythema nodosum and splenomegaly may be observed.⁵ Laboratory testing also may reveal markers of systemic inflammation such as leukocytosis with neutrophilia, elevated C-reactive protein levels, increased erythrocyte sedimentation rate, and thrombocytosis. Anemia and elevated hepatic enzyme levels also may be present in AF.² It is suspected that AF may be induced by low doses of isotretinoin therapy with concomitant inherited susceptibility.⁶

We report the case of a 21-year-old man who was referred to the Department of Dermatology by his primary care physician for evaluation of severe hemorrhagic lesions on the trunk following use of oral isotretinoin (Figure 1). Prior to development of the lesions, the patient had started weekly intramuscular injections of testosterone 500 mg, which he purchased online without consulting a physician, to address muscle mass reduction associated with sudden weight loss from intense physical training. After 8 months of testosterone supplementation along with continued physical training, the patient presented to his primary care physician for treatment of acne vulgaris on the back and trunk of 2 months’ duration. Oral isotretinoin 20 mg once daily was initiated; however, the patient reported that the acne lesions showed progression after 1 month of treatment. Isotretinoin was increased to a more weight-appropriate dosage of 60 mg once daily 2 weeks before admission to our dermatology clinic.

Treatment initially included cessation of isotretinoin and administration of prednisone, omeprazole, clindamycin, and doxycycline. Prednisone was given at a dosage of 40 mg once daily for 1 week, then decreased by 5 mg every 7 days. Omeprazole was given concurrently as prophylaxis for the gastrointestinal tract side effects of long-term prednisone use. Clindamycin was given at a dosage of 300 mg 3 times daily. Doxycycline was given for 6 weeks at a dosage of 100 mg twice daily. Topical octenidine dihydrochloride also was given.

The clinical diagnosis in our patient also was supported by the hypothesis that heredity, overactive immune reactions, bacterial infections, and use of some drugs (eg, isotretinoin, tetracycline, testosterone) can trigger AF.⁸ The most well-known theory is that low doses of isotretinoin induce AF.⁶ The majority of cases are caused by doses of less than 20 mg/kg once daily, but there have been reports of patients using full doses and developing this condition.⁹ The fact that the use of low- and high-dose isotretinoin can provoke AF suggests an idiosyncratic reaction that is not clearly dose related. The most dangerous triggering factor of AF is concomitant usage of testosterone and isotretinoin.¹⁰ Our patient used testosterone injections to increase muscle mass and underwent treatment with isotretinoin for acne.

Treatment of AF is controversial, as there is no standard therapy. Currently, steroids and isotretinoin are the treatments of choice. Antibiotic use is controversial because of a lack of randomized trials.¹¹

In the first stage of treatment, prednisone 0.5 to 1 mg/kg once daily is recommended as an initial anti-inflammatory therapy, with gradual dose reduction. According to evidence-based recommendations, a low dose of isotretinoin can be introduced after crusted lesions have healed. The overlapping therapy with steroids and isotretinoin should be provided for at least 4 weeks. High-potency topical corticosteroids can be used on granulation tissue, which can shorten the systemic treatment with prednisone or can be an alternative treatment for patients with contraindications to systemic corticosteroids.¹¹

Additionally, local care of the lesions including compresses and topical emollients is crucial. There are some case reports in which there is introduction of high doses of isotretinoin, subsequently with systemic steroids.^7,8,12 Seukeran and Cunliffe⁵ proved that it is beneficial to give acne prophylaxis to prevent further episodes. Our patient was similarly treated with systemic steroids and isotretinoin. Treatment guidelines for AF do not recommend oral antibiotics,¹¹ but data are limited in the case of isotretinoin-induced AF. Our patient was given doxycycline concomitant with systemic steroids, which was necessary due to signs of secondary infection from a lesion culture. Doxycycline was stopped when isotretinoin treatment was initiated to prevent pseudotumor cerebri. The patient achieved good clinical improvement with no relapse.

Using isotretinoin to treat acne vulgaris has many benefits, despite the possibility of developing AF as an extremely rare complication. Clinicians should be aware of the risk of this complication to make the diagnosis and provide appropriate care, especially in young men. It is particularly important to consider the possibility of concomitant testosterone and isotretinoin when documenting the patient’s medical history.