Cutis

Psoriasis is a chronic inflammatory disease that affects approximately 2% to 3% of the US population.¹ Patients with psoriasis are more likely to have cardiovascular risk factors (eg, obesity, metabolic syndrome) than individuals without psoriasis.² In fact, recent evidence has suggested that a diagnosis of psoriasis is an independent risk factor for cardiometabolic diseases including diabetes, major adverse cardiovascular events, and obesity.³ Given the well-recognized health benefits of physical activity and the associated reduction in coronary heart disease risk,⁴ patients with psoriasis specifically may benefit from regular participation in physical activity. Thus, an enhanced understanding of the relationship between psoriasis and vigorous physical activity would help determine the role of initiating and recommending interventions that implement physical activity for patients with psoriasis. A review was conducted to determine the relationship between psoriasis and vigorous physical activity.

Methods

An English-language literature search of PubMed articles indexed for MEDLINE (January 1, 1946–October 15, 2017) as well as articles in the Embase database (January 1, 1947–October 15, 2017) and Cochrane Library (January 1, 1992–October 15, 2017) using the terms psoriasis and physical activity was performed. The search strategy was established based on a prior review of vigorous physical activity in eczema.⁵ The article titles and/or abstracts were reviewed, and the studies were excluded if they did not evaluate physical activity in patients with psoriasis. Studies without a control group also were excluded. Articles on patients with psoriatic arthritis and studies that involved modification of dietary intake also were excluded.

Two reviewers (M.A. and E.B.L.) independently extracted data from the studies and compiled the results. The following factors were included in the data extracted: study year, location, and design; method of diagnosis of psoriasis; total number of patients included in the study; and age, gender, and level of physical activity of the study patients. Level of physical activity was the exposure, and diagnosis of psoriasis was the dependent variable. Physical activity was defined differently across the studies that were evaluated. To determine study quality, we implemented the Newcastle–Ottawa Scale (NOS), a 9-star scoring system that includes items such as selection criteria, comparability, and study outcome.⁶ Studies with an NOS score of 7 or higher were included in the meta-analysis.

Results

The literature search generated 353 nonduplicate articles. A thorough review of the articles yielded 4 studies that were incorporated in the final analysis.^7-10 We aimed to perform a meta-analysis; however, only 1 of the studies included in the final analysis had an NOS score of 7 or higher along with adequate data to be incorporated into our study.¹⁰ As a result, the meta-analysis was converted to a regular review.

The cross-sectional study we reviewed, which had an NOS score of 7, included males and females in the United States aged 20 to 59 years.¹⁰ Data were collected using the population-based National Health and Nutrition Examination Survey from 2003 to 2006. The survey measured the likelihood of participation in leisure-time moderate to vigorous physical activity (MVPA) and metabolic equivalent task (MET) minutes of MVPA in the past 30 days. Of 6549 participants, 385 were excluded from the analysis due to missing values for 1 or more of the study variables. Of the remaining 6164 participants, 84 (1.4%) reported having a diagnosis of psoriasis with few or no psoriasis patches at the time of the survey, and 71 (1.2%) reported having a diagnosis of psoriasis with few to extensive patches at the time of the survey.¹⁰

Participants with psoriasis were less likely to participate in MVPA in the previous 30 days compared to participants without psoriasis, but the association was not statistically significant.¹⁰ The study demonstrated that, on average, participants with psoriasis spent 31% (95% confidence interval [CI], −0.57 to −0.05) fewer MET minutes on leisure-time MVPA versus participants without psoriasis; however, this association was not statistically significant. It is important to note that the diagnosis of psoriasis was self-reported, and measures of disease duration or areas of involvement were not incorporated.

Comment

Our review revealed that vigorous physical activity may be reduced in patients with psoriasis compared to those without psoriasis. Initially, we aimed to perform a systematic review of the literature; however, only 1 study met the criteria for the systematic review, highlighting the need for more robust studies evaluating this subject.

Do et al¹⁰ demonstrated that psoriasis patients were less likely to participate in MVPA, but the findings were not statistically significant. Of those who participated in MVPA, MET minutes were fewer among patients with few to extensive skin lesions compared to those without psoriasis. The investigators suggested that psoriasis patients with more severe disease tend to exercise less and ultimately would benefit from regular vigorous physical activity.

Frankel et al⁷ performed a prospective cohort study in US women to evaluate the role of physical activity in preventing psoriasis. The investigators reported that the most physically active quintile had a lower multivariate relative risk of psoriasis (0.72; 95% CI, 0.59–0.89; P<.001 for trend) compared to the least active quintile.⁷ Additionally, vigorous physical activity, which was defined as 6 or more MET minutes, was associated with a significantly lower risk of incident psoriasis (0.66; 95% CI, 0.54–0.81; P<.001 for trend), which maintained significance after adjusting for body mass index (BMI). The investigators suggested that, by decreasing chronic inflammation and lowering levels of proinflammatory cytokines, vigorous physical activity may reduce the risk of psoriasis development in women.⁷ It is plausible that vigorous physical activity modifies the state of chronic inflammation, which could subsequently reduce the risk of developing psoriasis; however, further long-term, randomized, prospective studies are needed to verify the relationship between physical activity and development of psoriasis.

Torres et al⁸ performed a cross-sectional questionnaire study to assess physical activity in patients with severe psoriasis (defined as >10% body surface area involvement and/or disease requiring systemic therapy or phototherapy) versus healthy controls. Physical activity level was measured using the International Physical Activity Questionnaire. The odds ratio of low-level physical activity compared to non–low-level physical activity among psoriasis patients versus controls was 3.42 (95% CI, 1.47–7.91; P=.002). Additionally, the average total MET minutes of psoriasis patients were significantly reduced compared to those of the healthy controls (P=.001). Thus, the investigators suggested that vigorous physical activity is less likely in psoriasis patients, which may contribute to the increased risk of cardiovascular disease in this population.⁸ Vigorous physical activity would benefit patients with psoriasis to help lower the chronic state of inflammation and cardiometabolic comorbidities.

Demirel et al⁹ performed a study to compare aerobic exercise capacity and daily physical activity level in psoriasis patients (n=30) compared to controls (n=30). Daily physical activity, measured with an accelerometer, was significantly higher in male patients with psoriasis compared to controls (P=.021). No significant difference was reported in maximal aerobic capacity in both male and female psoriasis patients versus controls. The investigators suggested that the level of daily physical activity is not limited in psoriasis patients, yet the small sample size may limit the generalizability of the study.

The ability to dissipate heat during exercise seems to be diminished in patients with psoriasis. Specifically, it has been suggested that psoriasis lesions interfere with normal perspiration.¹¹ Moreover, joint involvement in patients with psoriatic arthritis may lead to physical functional disabilities that can interfere with the ability of these patients to participate in regular physical activity.^12-14 For this reason, our review excluded articles that evaluated patients with psoriatic arthritis. Despite this exclusion, it is important to consider that comorbid psoriatic arthritis in clinical practice may impede patients with psoriasis from participating in physical activity. Additionally, various social aspects also may limit physical activity in psoriasis patients; for instance, psoriasis patients often avoid activities that involve increased exposure of the skin (eg, communal showers, wearing sports attire).¹⁵

Furthermore, obese psoriasis patients are less likely to exercise compared to obese individuals without psoriasis.¹⁶ In patients with higher BMI, the risk of psoriasis is increased.¹⁷ A systematic review suggested that weight loss may improve psoriasis severity.¹⁸ Bariatric surgery also may improve psoriasis.¹⁹ Moreover, obesity may interfere with response to biologic therapies for psoriasis. Specifically, higher BMI is linked with lower response to fixed-dose biologic therapies compared to weight-based biologic options (eg, infliximab).^20,21

Conclusion

Given the increased risk of myocardial infarction in patients with psoriasis, it is important to recognize the barriers to physical activity that psoriasis patients face.²² Due to the considerable health benefits associated with regular physical activity, physicians should encourage patients with psoriasis to participate in physical activity as tolerated. Of note, the studies included in this review varied in their definitions of psoriasis disease severity and measures of physical activity level. Long-term, randomized, prospective studies are needed to clarify the relationship between psoriasis and physical activity. Evidence from these studies would help guide clinical recommendations regarding the role of physical activity for patients with psoriasis.

Psoriasis is a chronic inflammatory disease that affects approximately 2% to 3% of the US population.¹ Patients with psoriasis are more likely to have cardiovascular risk factors (eg, obesity, metabolic syndrome) than individuals without psoriasis.² In fact, recent evidence has suggested that a diagnosis of psoriasis is an independent risk factor for cardiometabolic diseases including diabetes, major adverse cardiovascular events, and obesity.³ Given the well-recognized health benefits of physical activity and the associated reduction in coronary heart disease risk,⁴ patients with psoriasis specifically may benefit from regular participation in physical activity. Thus, an enhanced understanding of the relationship between psoriasis and vigorous physical activity would help determine the role of initiating and recommending interventions that implement physical activity for patients with psoriasis. A review was conducted to determine the relationship between psoriasis and vigorous physical activity.

Methods

An English-language literature search of PubMed articles indexed for MEDLINE (January 1, 1946–October 15, 2017) as well as articles in the Embase database (January 1, 1947–October 15, 2017) and Cochrane Library (January 1, 1992–October 15, 2017) using the terms psoriasis and physical activity was performed. The search strategy was established based on a prior review of vigorous physical activity in eczema.⁵ The article titles and/or abstracts were reviewed, and the studies were excluded if they did not evaluate physical activity in patients with psoriasis. Studies without a control group also were excluded. Articles on patients with psoriatic arthritis and studies that involved modification of dietary intake also were excluded.

Two reviewers (M.A. and E.B.L.) independently extracted data from the studies and compiled the results. The following factors were included in the data extracted: study year, location, and design; method of diagnosis of psoriasis; total number of patients included in the study; and age, gender, and level of physical activity of the study patients. Level of physical activity was the exposure, and diagnosis of psoriasis was the dependent variable. Physical activity was defined differently across the studies that were evaluated. To determine study quality, we implemented the Newcastle–Ottawa Scale (NOS), a 9-star scoring system that includes items such as selection criteria, comparability, and study outcome.⁶ Studies with an NOS score of 7 or higher were included in the meta-analysis.

Results

The literature search generated 353 nonduplicate articles. A thorough review of the articles yielded 4 studies that were incorporated in the final analysis.^7-10 We aimed to perform a meta-analysis; however, only 1 of the studies included in the final analysis had an NOS score of 7 or higher along with adequate data to be incorporated into our study.¹⁰ As a result, the meta-analysis was converted to a regular review.

The cross-sectional study we reviewed, which had an NOS score of 7, included males and females in the United States aged 20 to 59 years.¹⁰ Data were collected using the population-based National Health and Nutrition Examination Survey from 2003 to 2006. The survey measured the likelihood of participation in leisure-time moderate to vigorous physical activity (MVPA) and metabolic equivalent task (MET) minutes of MVPA in the past 30 days. Of 6549 participants, 385 were excluded from the analysis due to missing values for 1 or more of the study variables. Of the remaining 6164 participants, 84 (1.4%) reported having a diagnosis of psoriasis with few or no psoriasis patches at the time of the survey, and 71 (1.2%) reported having a diagnosis of psoriasis with few to extensive patches at the time of the survey.¹⁰

Participants with psoriasis were less likely to participate in MVPA in the previous 30 days compared to participants without psoriasis, but the association was not statistically significant.¹⁰ The study demonstrated that, on average, participants with psoriasis spent 31% (95% confidence interval [CI], −0.57 to −0.05) fewer MET minutes on leisure-time MVPA versus participants without psoriasis; however, this association was not statistically significant. It is important to note that the diagnosis of psoriasis was self-reported, and measures of disease duration or areas of involvement were not incorporated.

Comment

Our review revealed that vigorous physical activity may be reduced in patients with psoriasis compared to those without psoriasis. Initially, we aimed to perform a systematic review of the literature; however, only 1 study met the criteria for the systematic review, highlighting the need for more robust studies evaluating this subject.

Do et al¹⁰ demonstrated that psoriasis patients were less likely to participate in MVPA, but the findings were not statistically significant. Of those who participated in MVPA, MET minutes were fewer among patients with few to extensive skin lesions compared to those without psoriasis. The investigators suggested that psoriasis patients with more severe disease tend to exercise less and ultimately would benefit from regular vigorous physical activity.

Frankel et al⁷ performed a prospective cohort study in US women to evaluate the role of physical activity in preventing psoriasis. The investigators reported that the most physically active quintile had a lower multivariate relative risk of psoriasis (0.72; 95% CI, 0.59–0.89; P<.001 for trend) compared to the least active quintile.⁷ Additionally, vigorous physical activity, which was defined as 6 or more MET minutes, was associated with a significantly lower risk of incident psoriasis (0.66; 95% CI, 0.54–0.81; P<.001 for trend), which maintained significance after adjusting for body mass index (BMI). The investigators suggested that, by decreasing chronic inflammation and lowering levels of proinflammatory cytokines, vigorous physical activity may reduce the risk of psoriasis development in women.⁷ It is plausible that vigorous physical activity modifies the state of chronic inflammation, which could subsequently reduce the risk of developing psoriasis; however, further long-term, randomized, prospective studies are needed to verify the relationship between physical activity and development of psoriasis.

Torres et al⁸ performed a cross-sectional questionnaire study to assess physical activity in patients with severe psoriasis (defined as >10% body surface area involvement and/or disease requiring systemic therapy or phototherapy) versus healthy controls. Physical activity level was measured using the International Physical Activity Questionnaire. The odds ratio of low-level physical activity compared to non–low-level physical activity among psoriasis patients versus controls was 3.42 (95% CI, 1.47–7.91; P=.002). Additionally, the average total MET minutes of psoriasis patients were significantly reduced compared to those of the healthy controls (P=.001). Thus, the investigators suggested that vigorous physical activity is less likely in psoriasis patients, which may contribute to the increased risk of cardiovascular disease in this population.⁸ Vigorous physical activity would benefit patients with psoriasis to help lower the chronic state of inflammation and cardiometabolic comorbidities.

Demirel et al⁹ performed a study to compare aerobic exercise capacity and daily physical activity level in psoriasis patients (n=30) compared to controls (n=30). Daily physical activity, measured with an accelerometer, was significantly higher in male patients with psoriasis compared to controls (P=.021). No significant difference was reported in maximal aerobic capacity in both male and female psoriasis patients versus controls. The investigators suggested that the level of daily physical activity is not limited in psoriasis patients, yet the small sample size may limit the generalizability of the study.

The ability to dissipate heat during exercise seems to be diminished in patients with psoriasis. Specifically, it has been suggested that psoriasis lesions interfere with normal perspiration.¹¹ Moreover, joint involvement in patients with psoriatic arthritis may lead to physical functional disabilities that can interfere with the ability of these patients to participate in regular physical activity.^12-14 For this reason, our review excluded articles that evaluated patients with psoriatic arthritis. Despite this exclusion, it is important to consider that comorbid psoriatic arthritis in clinical practice may impede patients with psoriasis from participating in physical activity. Additionally, various social aspects also may limit physical activity in psoriasis patients; for instance, psoriasis patients often avoid activities that involve increased exposure of the skin (eg, communal showers, wearing sports attire).¹⁵

Furthermore, obese psoriasis patients are less likely to exercise compared to obese individuals without psoriasis.¹⁶ In patients with higher BMI, the risk of psoriasis is increased.¹⁷ A systematic review suggested that weight loss may improve psoriasis severity.¹⁸ Bariatric surgery also may improve psoriasis.¹⁹ Moreover, obesity may interfere with response to biologic therapies for psoriasis. Specifically, higher BMI is linked with lower response to fixed-dose biologic therapies compared to weight-based biologic options (eg, infliximab).^20,21

Conclusion

Given the increased risk of myocardial infarction in patients with psoriasis, it is important to recognize the barriers to physical activity that psoriasis patients face.²² Due to the considerable health benefits associated with regular physical activity, physicians should encourage patients with psoriasis to participate in physical activity as tolerated. Of note, the studies included in this review varied in their definitions of psoriasis disease severity and measures of physical activity level. Long-term, randomized, prospective studies are needed to clarify the relationship between psoriasis and physical activity. Evidence from these studies would help guide clinical recommendations regarding the role of physical activity for patients with psoriasis.

Psoriasis is a chronic inflammatory disease that affects approximately 2% to 3% of the US population.¹ Patients with psoriasis are more likely to have cardiovascular risk factors (eg, obesity, metabolic syndrome) than individuals without psoriasis.² In fact, recent evidence has suggested that a diagnosis of psoriasis is an independent risk factor for cardiometabolic diseases including diabetes, major adverse cardiovascular events, and obesity.³ Given the well-recognized health benefits of physical activity and the associated reduction in coronary heart disease risk,⁴ patients with psoriasis specifically may benefit from regular participation in physical activity. Thus, an enhanced understanding of the relationship between psoriasis and vigorous physical activity would help determine the role of initiating and recommending interventions that implement physical activity for patients with psoriasis. A review was conducted to determine the relationship between psoriasis and vigorous physical activity.

Methods

An English-language literature search of PubMed articles indexed for MEDLINE (January 1, 1946–October 15, 2017) as well as articles in the Embase database (January 1, 1947–October 15, 2017) and Cochrane Library (January 1, 1992–October 15, 2017) using the terms psoriasis and physical activity was performed. The search strategy was established based on a prior review of vigorous physical activity in eczema.⁵ The article titles and/or abstracts were reviewed, and the studies were excluded if they did not evaluate physical activity in patients with psoriasis. Studies without a control group also were excluded. Articles on patients with psoriatic arthritis and studies that involved modification of dietary intake also were excluded.

Two reviewers (M.A. and E.B.L.) independently extracted data from the studies and compiled the results. The following factors were included in the data extracted: study year, location, and design; method of diagnosis of psoriasis; total number of patients included in the study; and age, gender, and level of physical activity of the study patients. Level of physical activity was the exposure, and diagnosis of psoriasis was the dependent variable. Physical activity was defined differently across the studies that were evaluated. To determine study quality, we implemented the Newcastle–Ottawa Scale (NOS), a 9-star scoring system that includes items such as selection criteria, comparability, and study outcome.⁶ Studies with an NOS score of 7 or higher were included in the meta-analysis.

Results

The literature search generated 353 nonduplicate articles. A thorough review of the articles yielded 4 studies that were incorporated in the final analysis.^7-10 We aimed to perform a meta-analysis; however, only 1 of the studies included in the final analysis had an NOS score of 7 or higher along with adequate data to be incorporated into our study.¹⁰ As a result, the meta-analysis was converted to a regular review.

The cross-sectional study we reviewed, which had an NOS score of 7, included males and females in the United States aged 20 to 59 years.¹⁰ Data were collected using the population-based National Health and Nutrition Examination Survey from 2003 to 2006. The survey measured the likelihood of participation in leisure-time moderate to vigorous physical activity (MVPA) and metabolic equivalent task (MET) minutes of MVPA in the past 30 days. Of 6549 participants, 385 were excluded from the analysis due to missing values for 1 or more of the study variables. Of the remaining 6164 participants, 84 (1.4%) reported having a diagnosis of psoriasis with few or no psoriasis patches at the time of the survey, and 71 (1.2%) reported having a diagnosis of psoriasis with few to extensive patches at the time of the survey.¹⁰

Participants with psoriasis were less likely to participate in MVPA in the previous 30 days compared to participants without psoriasis, but the association was not statistically significant.¹⁰ The study demonstrated that, on average, participants with psoriasis spent 31% (95% confidence interval [CI], −0.57 to −0.05) fewer MET minutes on leisure-time MVPA versus participants without psoriasis; however, this association was not statistically significant. It is important to note that the diagnosis of psoriasis was self-reported, and measures of disease duration or areas of involvement were not incorporated.

Comment

Our review revealed that vigorous physical activity may be reduced in patients with psoriasis compared to those without psoriasis. Initially, we aimed to perform a systematic review of the literature; however, only 1 study met the criteria for the systematic review, highlighting the need for more robust studies evaluating this subject.

Do et al¹⁰ demonstrated that psoriasis patients were less likely to participate in MVPA, but the findings were not statistically significant. Of those who participated in MVPA, MET minutes were fewer among patients with few to extensive skin lesions compared to those without psoriasis. The investigators suggested that psoriasis patients with more severe disease tend to exercise less and ultimately would benefit from regular vigorous physical activity.

Frankel et al⁷ performed a prospective cohort study in US women to evaluate the role of physical activity in preventing psoriasis. The investigators reported that the most physically active quintile had a lower multivariate relative risk of psoriasis (0.72; 95% CI, 0.59–0.89; P<.001 for trend) compared to the least active quintile.⁷ Additionally, vigorous physical activity, which was defined as 6 or more MET minutes, was associated with a significantly lower risk of incident psoriasis (0.66; 95% CI, 0.54–0.81; P<.001 for trend), which maintained significance after adjusting for body mass index (BMI). The investigators suggested that, by decreasing chronic inflammation and lowering levels of proinflammatory cytokines, vigorous physical activity may reduce the risk of psoriasis development in women.⁷ It is plausible that vigorous physical activity modifies the state of chronic inflammation, which could subsequently reduce the risk of developing psoriasis; however, further long-term, randomized, prospective studies are needed to verify the relationship between physical activity and development of psoriasis.

Torres et al⁸ performed a cross-sectional questionnaire study to assess physical activity in patients with severe psoriasis (defined as >10% body surface area involvement and/or disease requiring systemic therapy or phototherapy) versus healthy controls. Physical activity level was measured using the International Physical Activity Questionnaire. The odds ratio of low-level physical activity compared to non–low-level physical activity among psoriasis patients versus controls was 3.42 (95% CI, 1.47–7.91; P=.002). Additionally, the average total MET minutes of psoriasis patients were significantly reduced compared to those of the healthy controls (P=.001). Thus, the investigators suggested that vigorous physical activity is less likely in psoriasis patients, which may contribute to the increased risk of cardiovascular disease in this population.⁸ Vigorous physical activity would benefit patients with psoriasis to help lower the chronic state of inflammation and cardiometabolic comorbidities.

Demirel et al⁹ performed a study to compare aerobic exercise capacity and daily physical activity level in psoriasis patients (n=30) compared to controls (n=30). Daily physical activity, measured with an accelerometer, was significantly higher in male patients with psoriasis compared to controls (P=.021). No significant difference was reported in maximal aerobic capacity in both male and female psoriasis patients versus controls. The investigators suggested that the level of daily physical activity is not limited in psoriasis patients, yet the small sample size may limit the generalizability of the study.

The ability to dissipate heat during exercise seems to be diminished in patients with psoriasis. Specifically, it has been suggested that psoriasis lesions interfere with normal perspiration.¹¹ Moreover, joint involvement in patients with psoriatic arthritis may lead to physical functional disabilities that can interfere with the ability of these patients to participate in regular physical activity.^12-14 For this reason, our review excluded articles that evaluated patients with psoriatic arthritis. Despite this exclusion, it is important to consider that comorbid psoriatic arthritis in clinical practice may impede patients with psoriasis from participating in physical activity. Additionally, various social aspects also may limit physical activity in psoriasis patients; for instance, psoriasis patients often avoid activities that involve increased exposure of the skin (eg, communal showers, wearing sports attire).¹⁵

Furthermore, obese psoriasis patients are less likely to exercise compared to obese individuals without psoriasis.¹⁶ In patients with higher BMI, the risk of psoriasis is increased.¹⁷ A systematic review suggested that weight loss may improve psoriasis severity.¹⁸ Bariatric surgery also may improve psoriasis.¹⁹ Moreover, obesity may interfere with response to biologic therapies for psoriasis. Specifically, higher BMI is linked with lower response to fixed-dose biologic therapies compared to weight-based biologic options (eg, infliximab).^20,21

Conclusion

Given the increased risk of myocardial infarction in patients with psoriasis, it is important to recognize the barriers to physical activity that psoriasis patients face.²² Due to the considerable health benefits associated with regular physical activity, physicians should encourage patients with psoriasis to participate in physical activity as tolerated. Of note, the studies included in this review varied in their definitions of psoriasis disease severity and measures of physical activity level. Long-term, randomized, prospective studies are needed to clarify the relationship between psoriasis and physical activity. Evidence from these studies would help guide clinical recommendations regarding the role of physical activity for patients with psoriasis.

To the Editor:

A 65-year-old woman with B-cell marginal zone lymphoma presented with asymptomatic swelling and redness of the upper and lower eyelids of 1 week’s duration that was unresponsive to topical corticosteroids for presumptive allergic contact dermatitis. She denied any lip or tongue swelling, abdominal pain, or difficulty breathing or swallowing. Diagnosis of acquired angioedema (AAE) was confirmed on laboratory analysis, which showed C1q levels less than 3.6 mg/dL (reference range, 5.0–8.6 mg/dL), complement component 4 levels less than 8 mg/dL (reference range, 14–44 mg/dL), and C1 esterase inhibitor (C1-INH) levels of 3 mg/dL (reference range, 12–30 mg/dL).

A review of the patient’s medical record showed chronic thrombocytopenia secondary to previous chemotherapy. It was determined that the patient’s ecchymosis and purpura of the eyelids was secondary to a low platelet count resulting in bleeding into the area of angioedema (Figure). Serum protein electrophoresis did not demonstrate a monoclonal spike, and flow cytometry showed persistent B-cell leukemia without evidence of an aberrant T-cell antigenic profile. The edema and purpura of the eyelids spontaneously resolved over days, and the patient has had no recurrences to date. She was prescribed icatibant for treatment of future acute AAE attacks.

The common pathway of AAE involves the inability of C1-INH to stop activation of the complement, fibrinolytic, and contact systems. Failure to control the contact system leads to increased bradykinin production resulting in vasodilation and edema. Diagnosis of hereditary angioedema (HAE) types 1 and 2 can be confirmed in the setting of low complement component 4 and C1-INH functional levels and normal C1q levels; in AAE, C1q levels also are low.^1,2

The malignancies most frequently associated with AAE are non-Hodgkin lymphomas (eg, nodal marginal zone lymphoma, splenic marginal zone lymphoma), such as in our patient, as well as monoclonal gammopathies.² Triggers of AAE include trauma (eg, surgery, strenuous exercise), infection, and use of certain medications such as angiotensin-converting enzyme inhibitors and estrogen, but most episodes are spontaneous. Swelling of any cutaneous surface can occur in the setting of AAE. Mucosal involvement appears to be limited to the upper airway and gastrointestinal tract. Edema of the upper airway mucosa can lead to asphyxiation. In these cases, asphyxia can occur rapidly, and therefore all patients with upper airway involvement should present to the emergency room or call 911. Pain from swelling in the gastrointestinal tract can mimic an acute abdomen.³

Newly developed targeted therapies for HAE also appear to be effective in treating AAE. A summary of available treatments for angioedema is provided in the Table. Human plasma C1-INH can be used intravenously to treat acute attacks or can be given prophylactically to prevent attacks, but large doses may be necessary due to consumption of the protein.^1,3 The risk of bloodborne disease as a result of treatment exists, but screening and processing during production of the plasma makes this unlikely. Ecallantide is a reversible inhibitor of plasma kallikrein.^1,3 Rapid onset and subcutaneous dosing make it useful for treatment of acute AAE attacks. Because anaphylaxis has been reported in up to 3% of patients, ecallantide includes a boxed warning indicating that it must be administered by a health care professional with appropriate medical support to manage anaphylaxis and HAE.⁴ Icatibant is a selective competitive antagonist of bradykinin receptor B2. It can be administered subcutaneously by the patient, making it ideal for rapid treatment of angioedema.^1,3 Adverse events include pain and irritation at the injection site.

The most appropriate therapy for AAE is treatment of the underlying malignancy. Recognition and proper treatment of AAE is essential, as bradykinin-induced angioedema (AAE, HAE and angiotensin-converting enzyme inhibitor induced angioedema) does not respond to antihistamines and corticosteroids and instead requires therapy as discussed above.

To the Editor:

A 65-year-old woman with B-cell marginal zone lymphoma presented with asymptomatic swelling and redness of the upper and lower eyelids of 1 week’s duration that was unresponsive to topical corticosteroids for presumptive allergic contact dermatitis. She denied any lip or tongue swelling, abdominal pain, or difficulty breathing or swallowing. Diagnosis of acquired angioedema (AAE) was confirmed on laboratory analysis, which showed C1q levels less than 3.6 mg/dL (reference range, 5.0–8.6 mg/dL), complement component 4 levels less than 8 mg/dL (reference range, 14–44 mg/dL), and C1 esterase inhibitor (C1-INH) levels of 3 mg/dL (reference range, 12–30 mg/dL).

A review of the patient’s medical record showed chronic thrombocytopenia secondary to previous chemotherapy. It was determined that the patient’s ecchymosis and purpura of the eyelids was secondary to a low platelet count resulting in bleeding into the area of angioedema (Figure). Serum protein electrophoresis did not demonstrate a monoclonal spike, and flow cytometry showed persistent B-cell leukemia without evidence of an aberrant T-cell antigenic profile. The edema and purpura of the eyelids spontaneously resolved over days, and the patient has had no recurrences to date. She was prescribed icatibant for treatment of future acute AAE attacks.

The common pathway of AAE involves the inability of C1-INH to stop activation of the complement, fibrinolytic, and contact systems. Failure to control the contact system leads to increased bradykinin production resulting in vasodilation and edema. Diagnosis of hereditary angioedema (HAE) types 1 and 2 can be confirmed in the setting of low complement component 4 and C1-INH functional levels and normal C1q levels; in AAE, C1q levels also are low.^1,2

The malignancies most frequently associated with AAE are non-Hodgkin lymphomas (eg, nodal marginal zone lymphoma, splenic marginal zone lymphoma), such as in our patient, as well as monoclonal gammopathies.² Triggers of AAE include trauma (eg, surgery, strenuous exercise), infection, and use of certain medications such as angiotensin-converting enzyme inhibitors and estrogen, but most episodes are spontaneous. Swelling of any cutaneous surface can occur in the setting of AAE. Mucosal involvement appears to be limited to the upper airway and gastrointestinal tract. Edema of the upper airway mucosa can lead to asphyxiation. In these cases, asphyxia can occur rapidly, and therefore all patients with upper airway involvement should present to the emergency room or call 911. Pain from swelling in the gastrointestinal tract can mimic an acute abdomen.³

Newly developed targeted therapies for HAE also appear to be effective in treating AAE. A summary of available treatments for angioedema is provided in the Table. Human plasma C1-INH can be used intravenously to treat acute attacks or can be given prophylactically to prevent attacks, but large doses may be necessary due to consumption of the protein.^1,3 The risk of bloodborne disease as a result of treatment exists, but screening and processing during production of the plasma makes this unlikely. Ecallantide is a reversible inhibitor of plasma kallikrein.^1,3 Rapid onset and subcutaneous dosing make it useful for treatment of acute AAE attacks. Because anaphylaxis has been reported in up to 3% of patients, ecallantide includes a boxed warning indicating that it must be administered by a health care professional with appropriate medical support to manage anaphylaxis and HAE.⁴ Icatibant is a selective competitive antagonist of bradykinin receptor B2. It can be administered subcutaneously by the patient, making it ideal for rapid treatment of angioedema.^1,3 Adverse events include pain and irritation at the injection site.

The most appropriate therapy for AAE is treatment of the underlying malignancy. Recognition and proper treatment of AAE is essential, as bradykinin-induced angioedema (AAE, HAE and angiotensin-converting enzyme inhibitor induced angioedema) does not respond to antihistamines and corticosteroids and instead requires therapy as discussed above.

To the Editor:

A 65-year-old woman with B-cell marginal zone lymphoma presented with asymptomatic swelling and redness of the upper and lower eyelids of 1 week’s duration that was unresponsive to topical corticosteroids for presumptive allergic contact dermatitis. She denied any lip or tongue swelling, abdominal pain, or difficulty breathing or swallowing. Diagnosis of acquired angioedema (AAE) was confirmed on laboratory analysis, which showed C1q levels less than 3.6 mg/dL (reference range, 5.0–8.6 mg/dL), complement component 4 levels less than 8 mg/dL (reference range, 14–44 mg/dL), and C1 esterase inhibitor (C1-INH) levels of 3 mg/dL (reference range, 12–30 mg/dL).

A review of the patient’s medical record showed chronic thrombocytopenia secondary to previous chemotherapy. It was determined that the patient’s ecchymosis and purpura of the eyelids was secondary to a low platelet count resulting in bleeding into the area of angioedema (Figure). Serum protein electrophoresis did not demonstrate a monoclonal spike, and flow cytometry showed persistent B-cell leukemia without evidence of an aberrant T-cell antigenic profile. The edema and purpura of the eyelids spontaneously resolved over days, and the patient has had no recurrences to date. She was prescribed icatibant for treatment of future acute AAE attacks.

The common pathway of AAE involves the inability of C1-INH to stop activation of the complement, fibrinolytic, and contact systems. Failure to control the contact system leads to increased bradykinin production resulting in vasodilation and edema. Diagnosis of hereditary angioedema (HAE) types 1 and 2 can be confirmed in the setting of low complement component 4 and C1-INH functional levels and normal C1q levels; in AAE, C1q levels also are low.^1,2

The malignancies most frequently associated with AAE are non-Hodgkin lymphomas (eg, nodal marginal zone lymphoma, splenic marginal zone lymphoma), such as in our patient, as well as monoclonal gammopathies.² Triggers of AAE include trauma (eg, surgery, strenuous exercise), infection, and use of certain medications such as angiotensin-converting enzyme inhibitors and estrogen, but most episodes are spontaneous. Swelling of any cutaneous surface can occur in the setting of AAE. Mucosal involvement appears to be limited to the upper airway and gastrointestinal tract. Edema of the upper airway mucosa can lead to asphyxiation. In these cases, asphyxia can occur rapidly, and therefore all patients with upper airway involvement should present to the emergency room or call 911. Pain from swelling in the gastrointestinal tract can mimic an acute abdomen.³

Newly developed targeted therapies for HAE also appear to be effective in treating AAE. A summary of available treatments for angioedema is provided in the Table. Human plasma C1-INH can be used intravenously to treat acute attacks or can be given prophylactically to prevent attacks, but large doses may be necessary due to consumption of the protein.^1,3 The risk of bloodborne disease as a result of treatment exists, but screening and processing during production of the plasma makes this unlikely. Ecallantide is a reversible inhibitor of plasma kallikrein.^1,3 Rapid onset and subcutaneous dosing make it useful for treatment of acute AAE attacks. Because anaphylaxis has been reported in up to 3% of patients, ecallantide includes a boxed warning indicating that it must be administered by a health care professional with appropriate medical support to manage anaphylaxis and HAE.⁴ Icatibant is a selective competitive antagonist of bradykinin receptor B2. It can be administered subcutaneously by the patient, making it ideal for rapid treatment of angioedema.^1,3 Adverse events include pain and irritation at the injection site.

The most appropriate therapy for AAE is treatment of the underlying malignancy. Recognition and proper treatment of AAE is essential, as bradykinin-induced angioedema (AAE, HAE and angiotensin-converting enzyme inhibitor induced angioedema) does not respond to antihistamines and corticosteroids and instead requires therapy as discussed above.

To the Editor:

A 40-year-old woman with a history of stage IIIC ovarian cancer presented with progressing abdominal erythema and pain of 1 month’s duration. She had been diagnosed 4 years prior with grade 3, poorly differentiated papillary serous carcinoma involving the bilateral ovaries, uterine tubes, uterus, and omentum with lymphovascular invasion. She underwent tumor resection and debulking followed by paclitaxel plus platinum-based chemotherapy. The cancer recurred 2 years later with carcinomatous ascites. She declined chemotherapy but underwent therapeutic paracentesis.

One month prior to presentation, the patient developed a small, tender, erythematous patch on the abdomen. Her primary physician started her on cephalexin for presumed cellulitis without improvement. The erythema continued to spread on the abdomen with worsening pain, which prompted her presentation to the emergency department. She was admitted and started on intravenous vancomycin.

On admission to the hospital, the patient was cachexic and afebrile with a white blood cell count of 10,400/µL (reference range, 4500–11,000/µL). Physical examination revealed a well-demarcated, 15×20-cm, erythematous, blanchable, indurated plaque in the periumbilical region (Figure 1). The plaque was tender to palpation with guarding but no increased warmth. Punch biopsies of the abdominal skin revealed carcinoma within the lymphatic channels in the deep dermis and dilated lymphatics throughout the overlying dermis (Figure 2). These findings were diagnostic for carcinoma erysipeloides. Tissue and blood cultures were negative for bacterial, fungal, or mycobacterial growth. Vancomycin was discontinued, and she was discharged with pain medication. She declined chemotherapy due to the potential side effects and elected to continue symptomatic management with palliative paracentesis. After she was discharged, she underwent a tunneled pleural catheterization for recurrent malignant pleural effusions.

Carcinoma erysipeloides is a rare cutaneous metastasis secondary to internal malignancy that presents as well-demarcated areas of erythema and is sometimes misdiagnosed as cellulitis or erysipelas. Histology is notable for lymphovascular congestion without inflammation. Carcinoma erysipeloides most commonly is associated with breast cancer, but it also has been described in cancers of the prostate, larynx, stomach, lungs, thyroid, parotid gland, fallopian tubes, cervix, pancreas, and metastatic melanoma.^1-5 While the pathogenesis of carcinoma erysipeloides is poorly understood, it is thought to occur by direct spread of tumor cells from the lymph nodes to the cutaneous lymphatics, causing obstruction and edema.

Ovarian cancer has the highest mortality of all gynecologic cancers and often is associated with delayed diagnosis. Cutaneous metastasis is a late manifestation often presenting as subcutaneous nodules.^6,7 Carcinoma erysipeloides is an even rarer presentation of ovarian cancer, with a poor prognosis and a median survival of 18 months.⁸ A PubMed search of articles indexed for MEDLINE using the term carcinoma erysipeloides revealed 9 cases of carcinoma erysipeloides from ovarian cancer: 1 describing erythematous papules, plaques, and zosteriform vesicles on the upper thighs to the lower abdomen,⁹ and 8 describing erythematous plaques on the breasts.^8,10 We report a case of carcinoma erysipeloides associated with stage IIIc ovarian cancer localized to the abdominal wall mimicking cellulitis. Our report reminds clinicians of this important diagnosis in ovarian cancer and of the importance of a skin biopsy to expedite a definitive diagnosis. Immunohistochemistry using ovarian tumor markers (eg, paired-box gene 8, cancer antigen 125) is an additional tool to accurately identify malignant cells in skin biopsy.^8,10 Once diagnosed, primary treatment for carcinoma erysipeloides is treatment of the underlying malignancy.

To the Editor:

A 40-year-old woman with a history of stage IIIC ovarian cancer presented with progressing abdominal erythema and pain of 1 month’s duration. She had been diagnosed 4 years prior with grade 3, poorly differentiated papillary serous carcinoma involving the bilateral ovaries, uterine tubes, uterus, and omentum with lymphovascular invasion. She underwent tumor resection and debulking followed by paclitaxel plus platinum-based chemotherapy. The cancer recurred 2 years later with carcinomatous ascites. She declined chemotherapy but underwent therapeutic paracentesis.

One month prior to presentation, the patient developed a small, tender, erythematous patch on the abdomen. Her primary physician started her on cephalexin for presumed cellulitis without improvement. The erythema continued to spread on the abdomen with worsening pain, which prompted her presentation to the emergency department. She was admitted and started on intravenous vancomycin.

On admission to the hospital, the patient was cachexic and afebrile with a white blood cell count of 10,400/µL (reference range, 4500–11,000/µL). Physical examination revealed a well-demarcated, 15×20-cm, erythematous, blanchable, indurated plaque in the periumbilical region (Figure 1). The plaque was tender to palpation with guarding but no increased warmth. Punch biopsies of the abdominal skin revealed carcinoma within the lymphatic channels in the deep dermis and dilated lymphatics throughout the overlying dermis (Figure 2). These findings were diagnostic for carcinoma erysipeloides. Tissue and blood cultures were negative for bacterial, fungal, or mycobacterial growth. Vancomycin was discontinued, and she was discharged with pain medication. She declined chemotherapy due to the potential side effects and elected to continue symptomatic management with palliative paracentesis. After she was discharged, she underwent a tunneled pleural catheterization for recurrent malignant pleural effusions.

Carcinoma erysipeloides is a rare cutaneous metastasis secondary to internal malignancy that presents as well-demarcated areas of erythema and is sometimes misdiagnosed as cellulitis or erysipelas. Histology is notable for lymphovascular congestion without inflammation. Carcinoma erysipeloides most commonly is associated with breast cancer, but it also has been described in cancers of the prostate, larynx, stomach, lungs, thyroid, parotid gland, fallopian tubes, cervix, pancreas, and metastatic melanoma.^1-5 While the pathogenesis of carcinoma erysipeloides is poorly understood, it is thought to occur by direct spread of tumor cells from the lymph nodes to the cutaneous lymphatics, causing obstruction and edema.

Ovarian cancer has the highest mortality of all gynecologic cancers and often is associated with delayed diagnosis. Cutaneous metastasis is a late manifestation often presenting as subcutaneous nodules.^6,7 Carcinoma erysipeloides is an even rarer presentation of ovarian cancer, with a poor prognosis and a median survival of 18 months.⁸ A PubMed search of articles indexed for MEDLINE using the term carcinoma erysipeloides revealed 9 cases of carcinoma erysipeloides from ovarian cancer: 1 describing erythematous papules, plaques, and zosteriform vesicles on the upper thighs to the lower abdomen,⁹ and 8 describing erythematous plaques on the breasts.^8,10 We report a case of carcinoma erysipeloides associated with stage IIIc ovarian cancer localized to the abdominal wall mimicking cellulitis. Our report reminds clinicians of this important diagnosis in ovarian cancer and of the importance of a skin biopsy to expedite a definitive diagnosis. Immunohistochemistry using ovarian tumor markers (eg, paired-box gene 8, cancer antigen 125) is an additional tool to accurately identify malignant cells in skin biopsy.^8,10 Once diagnosed, primary treatment for carcinoma erysipeloides is treatment of the underlying malignancy.

To the Editor:

A 40-year-old woman with a history of stage IIIC ovarian cancer presented with progressing abdominal erythema and pain of 1 month’s duration. She had been diagnosed 4 years prior with grade 3, poorly differentiated papillary serous carcinoma involving the bilateral ovaries, uterine tubes, uterus, and omentum with lymphovascular invasion. She underwent tumor resection and debulking followed by paclitaxel plus platinum-based chemotherapy. The cancer recurred 2 years later with carcinomatous ascites. She declined chemotherapy but underwent therapeutic paracentesis.

One month prior to presentation, the patient developed a small, tender, erythematous patch on the abdomen. Her primary physician started her on cephalexin for presumed cellulitis without improvement. The erythema continued to spread on the abdomen with worsening pain, which prompted her presentation to the emergency department. She was admitted and started on intravenous vancomycin.

On admission to the hospital, the patient was cachexic and afebrile with a white blood cell count of 10,400/µL (reference range, 4500–11,000/µL). Physical examination revealed a well-demarcated, 15×20-cm, erythematous, blanchable, indurated plaque in the periumbilical region (Figure 1). The plaque was tender to palpation with guarding but no increased warmth. Punch biopsies of the abdominal skin revealed carcinoma within the lymphatic channels in the deep dermis and dilated lymphatics throughout the overlying dermis (Figure 2). These findings were diagnostic for carcinoma erysipeloides. Tissue and blood cultures were negative for bacterial, fungal, or mycobacterial growth. Vancomycin was discontinued, and she was discharged with pain medication. She declined chemotherapy due to the potential side effects and elected to continue symptomatic management with palliative paracentesis. After she was discharged, she underwent a tunneled pleural catheterization for recurrent malignant pleural effusions.

Carcinoma erysipeloides is a rare cutaneous metastasis secondary to internal malignancy that presents as well-demarcated areas of erythema and is sometimes misdiagnosed as cellulitis or erysipelas. Histology is notable for lymphovascular congestion without inflammation. Carcinoma erysipeloides most commonly is associated with breast cancer, but it also has been described in cancers of the prostate, larynx, stomach, lungs, thyroid, parotid gland, fallopian tubes, cervix, pancreas, and metastatic melanoma.^1-5 While the pathogenesis of carcinoma erysipeloides is poorly understood, it is thought to occur by direct spread of tumor cells from the lymph nodes to the cutaneous lymphatics, causing obstruction and edema.

Ovarian cancer has the highest mortality of all gynecologic cancers and often is associated with delayed diagnosis. Cutaneous metastasis is a late manifestation often presenting as subcutaneous nodules.^6,7 Carcinoma erysipeloides is an even rarer presentation of ovarian cancer, with a poor prognosis and a median survival of 18 months.⁸ A PubMed search of articles indexed for MEDLINE using the term carcinoma erysipeloides revealed 9 cases of carcinoma erysipeloides from ovarian cancer: 1 describing erythematous papules, plaques, and zosteriform vesicles on the upper thighs to the lower abdomen,⁹ and 8 describing erythematous plaques on the breasts.^8,10 We report a case of carcinoma erysipeloides associated with stage IIIc ovarian cancer localized to the abdominal wall mimicking cellulitis. Our report reminds clinicians of this important diagnosis in ovarian cancer and of the importance of a skin biopsy to expedite a definitive diagnosis. Immunohistochemistry using ovarian tumor markers (eg, paired-box gene 8, cancer antigen 125) is an additional tool to accurately identify malignant cells in skin biopsy.^8,10 Once diagnosed, primary treatment for carcinoma erysipeloides is treatment of the underlying malignancy.

To the Editor:

Sentinel lymph node (SLN) biopsies routinely are performed to detect regional metastases in a variety of malignancies, including breast cancer, squamous cell carcinoma, Merkel cell carcinoma, and melanoma. Histologic examination of an SLN occasionally enables detection of other unsuspected underlying diseases that typically are inflammatory in nature. Although concomitant hematolymphoid malignancy, particularly chronic lymphocytic leukemia, has been reported in SLNs, collision of 2 different solid tumors in the same SLN is rare.^1,2 We report a unique case documenting collision of both metastatic melanoma and prostatic adenocarcinoma detected in an SLN to raise awareness of the diagnostic challenges occurring in patients with coexisting malignancies.

A 71-year-old man with a history of metastatic prostatic adenocarcinoma to the bone presented for treatment of a melanoma that was newly diagnosed by an outside dermatologist. The patient’s medical history was notable for radical prostatectomy performed 15 years prior for treatment of a prostatic adenocarcinoma (Gleason score unknown) followed by bilateral orchiectomy performed 7 years later after his serum prostate-specific antigen (PSA) level began to rise, with no response to goserelin (a gonadotropin-releasing hormone agonist) therapy. Two years prior to the diagnosis of metastatic disease, his PSA level started to rise again and the patient received bicalutamide with little improvement, followed by 8 cycles of docetaxel. His PSA level improved and he most recently was being treated with abiraterone acetate. The patient’s latest computed tomography scan showed that the bony metastases secondary to prostatic adenocarcinoma had progressed. His serum PSA level was 105 ng/mL (reference range, <4.0 ng/mL) at the current presentation, elevated from 64 ng/mL one year prior.

Recently, the patient had noted a changing pigmented skin lesion on the left side of the flank. The patient described the lesion as a “black mole” first appearing 2 years prior, which had begun to ooze, change shape, and become darker and more nodular. A shave biopsy revealed a primary cutaneous malignant melanoma at least 3.4 mm in depth with ulceration and a mitotic rate of 15/mm². No molecular studies were performed on the melanoma. Standard treatment via wide local excision and sentinel lymphadenectomy was planned.

Lymphoscintigraphy revealed 3 left draining axillary lymph nodes. The patient was treated with wide local excision and left axillary SLN biopsy. Five SLNs and 3 non-SLNs were excised. Per protocol, all SLNs were examined pathologically with serial sections: 2 hematoxylin and eosin–stained levels, S-100, and melan-A immunohistochemical stains. No residual melanoma was identified in the wide-excision specimen. Examination of the left axillary SLNs revealed metastatic melanoma in 3 of 5 SLNs. Two SLNs demonstrated total replacement by metastatic melanoma. A third SLN revealed a metastatic malignant neoplasm occupying 75% of the nodal area (Figure, A). S-100 and melan-A immunohistochemical staining were negative in this nodule but revealed small aggregates and isolated tumor cells distinct from this nodule that were diagnostic of micrometastatic melanoma (Figures, B and C). The tumor cells in the large nodule were histologically distinct from the melanoma and were instead composed of nests of epithelioid cells with clear cytoplasm (Figure, D). Upon further immunohistochemical staining, this tumor was strongly positive for AE1/AE3 keratin and PIN4 cocktail (cytokeratin 5, cytokeratin 15, p63, and p504s/alpha-methylacyl-CoA-racemase)(Figure, E) with focal positivity for PSA and prostatic acid phosphatase, diagnostic of metastatic adenocarcinoma of prostate origin.

A positron emission tomography scan performed a few days after the discovery of metastatic prostatic adenocarcinoma in the SLNs showed expected postoperative changes (eg, increased activity from procedure-related inflammation) in the left side of the flank and axilla as well as moderately hypermetabolic left supraclavicular lymph nodes suspicious for viable metastatic disease. Subsequent fine-needle aspiration of the aforementioned lymph nodes revealed metastatic prostatic adenocarcinoma. The preoperative lymphoscintigraphy at the time of SLN biopsy did not show drainage to the left supraclavicular nodal basin.

Based on a discussion of the patient’s case during a multidisciplinary tumor board consultation, the benefit of performing completion lymph node dissection for melanoma management did not outweigh the risks. Accordingly, the patient received adjuvant radiation therapy to the axillary nodal basin. He was started on ketoconazole and zoledronic acid therapy for metastatic prostate adenocarcinoma and was alive with disease at 6-month follow-up. The finding of both metastatic melanoma and prostate adenocarcinoma detected in an SLN after wide excision and SLN biopsy for cutaneous melanoma is a unique report of collision of these 2 tumors. Rare cases of collision between 2 solid tumors occurring in the same lymph node have involved prostate adenocarcinoma as one of the solid tumor components.^1,3 Detection of tumor collision on lymph node biopsy between prostatic adenocarcinoma and urothelial carcinoma has been documented in 2 separate cases.¹ Three additional cases of concurrent prostatic adenocarcinoma and colorectal adenocarcinoma identified on lymph node biopsy have been reported.^1,3 Although never proven statistically, it is likely that these concurrent diagnoses are due to the high incidences of prostate and colorectal adenocarcinomas in the general US population; they are ranked first and third, respectively, for cancer incidence in US males.⁴

As demonstrated in the current case and the available literature, immunohistochemical stains play a vital role in the detection of tumor collision phenomena as well as identification of histologic source of the metastases. Furthermore, thorough histopathologic examination of biopsy specimens in the context of a patient’s clinical history remains paramount in obtaining an accurate diagnosis. Earlier identification of second malignancies in SLNs can alert the clinician to the presence of relapse of a known concurrent malignancy before it is clinically apparent, enhancing the possibility of more effective treatment of earlier disease. As has been demonstrated for lymphoma and melanoma, in rare cases awareness of the possibility of a second malignancy in the SLN can result in earlier initial diagnosis of undiscovered malignancy.²

To the Editor:

Sentinel lymph node (SLN) biopsies routinely are performed to detect regional metastases in a variety of malignancies, including breast cancer, squamous cell carcinoma, Merkel cell carcinoma, and melanoma. Histologic examination of an SLN occasionally enables detection of other unsuspected underlying diseases that typically are inflammatory in nature. Although concomitant hematolymphoid malignancy, particularly chronic lymphocytic leukemia, has been reported in SLNs, collision of 2 different solid tumors in the same SLN is rare.^1,2 We report a unique case documenting collision of both metastatic melanoma and prostatic adenocarcinoma detected in an SLN to raise awareness of the diagnostic challenges occurring in patients with coexisting malignancies.

A 71-year-old man with a history of metastatic prostatic adenocarcinoma to the bone presented for treatment of a melanoma that was newly diagnosed by an outside dermatologist. The patient’s medical history was notable for radical prostatectomy performed 15 years prior for treatment of a prostatic adenocarcinoma (Gleason score unknown) followed by bilateral orchiectomy performed 7 years later after his serum prostate-specific antigen (PSA) level began to rise, with no response to goserelin (a gonadotropin-releasing hormone agonist) therapy. Two years prior to the diagnosis of metastatic disease, his PSA level started to rise again and the patient received bicalutamide with little improvement, followed by 8 cycles of docetaxel. His PSA level improved and he most recently was being treated with abiraterone acetate. The patient’s latest computed tomography scan showed that the bony metastases secondary to prostatic adenocarcinoma had progressed. His serum PSA level was 105 ng/mL (reference range, <4.0 ng/mL) at the current presentation, elevated from 64 ng/mL one year prior.

Recently, the patient had noted a changing pigmented skin lesion on the left side of the flank. The patient described the lesion as a “black mole” first appearing 2 years prior, which had begun to ooze, change shape, and become darker and more nodular. A shave biopsy revealed a primary cutaneous malignant melanoma at least 3.4 mm in depth with ulceration and a mitotic rate of 15/mm². No molecular studies were performed on the melanoma. Standard treatment via wide local excision and sentinel lymphadenectomy was planned.

Lymphoscintigraphy revealed 3 left draining axillary lymph nodes. The patient was treated with wide local excision and left axillary SLN biopsy. Five SLNs and 3 non-SLNs were excised. Per protocol, all SLNs were examined pathologically with serial sections: 2 hematoxylin and eosin–stained levels, S-100, and melan-A immunohistochemical stains. No residual melanoma was identified in the wide-excision specimen. Examination of the left axillary SLNs revealed metastatic melanoma in 3 of 5 SLNs. Two SLNs demonstrated total replacement by metastatic melanoma. A third SLN revealed a metastatic malignant neoplasm occupying 75% of the nodal area (Figure, A). S-100 and melan-A immunohistochemical staining were negative in this nodule but revealed small aggregates and isolated tumor cells distinct from this nodule that were diagnostic of micrometastatic melanoma (Figures, B and C). The tumor cells in the large nodule were histologically distinct from the melanoma and were instead composed of nests of epithelioid cells with clear cytoplasm (Figure, D). Upon further immunohistochemical staining, this tumor was strongly positive for AE1/AE3 keratin and PIN4 cocktail (cytokeratin 5, cytokeratin 15, p63, and p504s/alpha-methylacyl-CoA-racemase)(Figure, E) with focal positivity for PSA and prostatic acid phosphatase, diagnostic of metastatic adenocarcinoma of prostate origin.

A positron emission tomography scan performed a few days after the discovery of metastatic prostatic adenocarcinoma in the SLNs showed expected postoperative changes (eg, increased activity from procedure-related inflammation) in the left side of the flank and axilla as well as moderately hypermetabolic left supraclavicular lymph nodes suspicious for viable metastatic disease. Subsequent fine-needle aspiration of the aforementioned lymph nodes revealed metastatic prostatic adenocarcinoma. The preoperative lymphoscintigraphy at the time of SLN biopsy did not show drainage to the left supraclavicular nodal basin.

Based on a discussion of the patient’s case during a multidisciplinary tumor board consultation, the benefit of performing completion lymph node dissection for melanoma management did not outweigh the risks. Accordingly, the patient received adjuvant radiation therapy to the axillary nodal basin. He was started on ketoconazole and zoledronic acid therapy for metastatic prostate adenocarcinoma and was alive with disease at 6-month follow-up. The finding of both metastatic melanoma and prostate adenocarcinoma detected in an SLN after wide excision and SLN biopsy for cutaneous melanoma is a unique report of collision of these 2 tumors. Rare cases of collision between 2 solid tumors occurring in the same lymph node have involved prostate adenocarcinoma as one of the solid tumor components.^1,3 Detection of tumor collision on lymph node biopsy between prostatic adenocarcinoma and urothelial carcinoma has been documented in 2 separate cases.¹ Three additional cases of concurrent prostatic adenocarcinoma and colorectal adenocarcinoma identified on lymph node biopsy have been reported.^1,3 Although never proven statistically, it is likely that these concurrent diagnoses are due to the high incidences of prostate and colorectal adenocarcinomas in the general US population; they are ranked first and third, respectively, for cancer incidence in US males.⁴

As demonstrated in the current case and the available literature, immunohistochemical stains play a vital role in the detection of tumor collision phenomena as well as identification of histologic source of the metastases. Furthermore, thorough histopathologic examination of biopsy specimens in the context of a patient’s clinical history remains paramount in obtaining an accurate diagnosis. Earlier identification of second malignancies in SLNs can alert the clinician to the presence of relapse of a known concurrent malignancy before it is clinically apparent, enhancing the possibility of more effective treatment of earlier disease. As has been demonstrated for lymphoma and melanoma, in rare cases awareness of the possibility of a second malignancy in the SLN can result in earlier initial diagnosis of undiscovered malignancy.²

To the Editor:

Sentinel lymph node (SLN) biopsies routinely are performed to detect regional metastases in a variety of malignancies, including breast cancer, squamous cell carcinoma, Merkel cell carcinoma, and melanoma. Histologic examination of an SLN occasionally enables detection of other unsuspected underlying diseases that typically are inflammatory in nature. Although concomitant hematolymphoid malignancy, particularly chronic lymphocytic leukemia, has been reported in SLNs, collision of 2 different solid tumors in the same SLN is rare.^1,2 We report a unique case documenting collision of both metastatic melanoma and prostatic adenocarcinoma detected in an SLN to raise awareness of the diagnostic challenges occurring in patients with coexisting malignancies.

A 71-year-old man with a history of metastatic prostatic adenocarcinoma to the bone presented for treatment of a melanoma that was newly diagnosed by an outside dermatologist. The patient’s medical history was notable for radical prostatectomy performed 15 years prior for treatment of a prostatic adenocarcinoma (Gleason score unknown) followed by bilateral orchiectomy performed 7 years later after his serum prostate-specific antigen (PSA) level began to rise, with no response to goserelin (a gonadotropin-releasing hormone agonist) therapy. Two years prior to the diagnosis of metastatic disease, his PSA level started to rise again and the patient received bicalutamide with little improvement, followed by 8 cycles of docetaxel. His PSA level improved and he most recently was being treated with abiraterone acetate. The patient’s latest computed tomography scan showed that the bony metastases secondary to prostatic adenocarcinoma had progressed. His serum PSA level was 105 ng/mL (reference range, <4.0 ng/mL) at the current presentation, elevated from 64 ng/mL one year prior.

Recently, the patient had noted a changing pigmented skin lesion on the left side of the flank. The patient described the lesion as a “black mole” first appearing 2 years prior, which had begun to ooze, change shape, and become darker and more nodular. A shave biopsy revealed a primary cutaneous malignant melanoma at least 3.4 mm in depth with ulceration and a mitotic rate of 15/mm². No molecular studies were performed on the melanoma. Standard treatment via wide local excision and sentinel lymphadenectomy was planned.

Lymphoscintigraphy revealed 3 left draining axillary lymph nodes. The patient was treated with wide local excision and left axillary SLN biopsy. Five SLNs and 3 non-SLNs were excised. Per protocol, all SLNs were examined pathologically with serial sections: 2 hematoxylin and eosin–stained levels, S-100, and melan-A immunohistochemical stains. No residual melanoma was identified in the wide-excision specimen. Examination of the left axillary SLNs revealed metastatic melanoma in 3 of 5 SLNs. Two SLNs demonstrated total replacement by metastatic melanoma. A third SLN revealed a metastatic malignant neoplasm occupying 75% of the nodal area (Figure, A). S-100 and melan-A immunohistochemical staining were negative in this nodule but revealed small aggregates and isolated tumor cells distinct from this nodule that were diagnostic of micrometastatic melanoma (Figures, B and C). The tumor cells in the large nodule were histologically distinct from the melanoma and were instead composed of nests of epithelioid cells with clear cytoplasm (Figure, D). Upon further immunohistochemical staining, this tumor was strongly positive for AE1/AE3 keratin and PIN4 cocktail (cytokeratin 5, cytokeratin 15, p63, and p504s/alpha-methylacyl-CoA-racemase)(Figure, E) with focal positivity for PSA and prostatic acid phosphatase, diagnostic of metastatic adenocarcinoma of prostate origin.

A positron emission tomography scan performed a few days after the discovery of metastatic prostatic adenocarcinoma in the SLNs showed expected postoperative changes (eg, increased activity from procedure-related inflammation) in the left side of the flank and axilla as well as moderately hypermetabolic left supraclavicular lymph nodes suspicious for viable metastatic disease. Subsequent fine-needle aspiration of the aforementioned lymph nodes revealed metastatic prostatic adenocarcinoma. The preoperative lymphoscintigraphy at the time of SLN biopsy did not show drainage to the left supraclavicular nodal basin.

Based on a discussion of the patient’s case during a multidisciplinary tumor board consultation, the benefit of performing completion lymph node dissection for melanoma management did not outweigh the risks. Accordingly, the patient received adjuvant radiation therapy to the axillary nodal basin. He was started on ketoconazole and zoledronic acid therapy for metastatic prostate adenocarcinoma and was alive with disease at 6-month follow-up. The finding of both metastatic melanoma and prostate adenocarcinoma detected in an SLN after wide excision and SLN biopsy for cutaneous melanoma is a unique report of collision of these 2 tumors. Rare cases of collision between 2 solid tumors occurring in the same lymph node have involved prostate adenocarcinoma as one of the solid tumor components.^1,3 Detection of tumor collision on lymph node biopsy between prostatic adenocarcinoma and urothelial carcinoma has been documented in 2 separate cases.¹ Three additional cases of concurrent prostatic adenocarcinoma and colorectal adenocarcinoma identified on lymph node biopsy have been reported.^1,3 Although never proven statistically, it is likely that these concurrent diagnoses are due to the high incidences of prostate and colorectal adenocarcinomas in the general US population; they are ranked first and third, respectively, for cancer incidence in US males.⁴

As demonstrated in the current case and the available literature, immunohistochemical stains play a vital role in the detection of tumor collision phenomena as well as identification of histologic source of the metastases. Furthermore, thorough histopathologic examination of biopsy specimens in the context of a patient’s clinical history remains paramount in obtaining an accurate diagnosis. Earlier identification of second malignancies in SLNs can alert the clinician to the presence of relapse of a known concurrent malignancy before it is clinically apparent, enhancing the possibility of more effective treatment of earlier disease. As has been demonstrated for lymphoma and melanoma, in rare cases awareness of the possibility of a second malignancy in the SLN can result in earlier initial diagnosis of undiscovered malignancy.²

The Diagnosis: Granuloma Faciale

A biopsy from a scalp lesion showed an intense mixed inflammatory infiltrate mainly consisting of eosinophils, but lymphocytes, histiocytes, neutrophils, and plasma cells also were present. A grenz zone was observed between the dermal infiltrate and epidermis. Perivascular infiltrates were penetrating vessel walls, and hyalinization of the vessel walls also was seen (Figure 1). Direct immunofluorescence demonstrated IgG positivity on vessel walls (Figure 2). A diagnosis of granuloma faciale with extrafacial lesions was made. Twice daily application of tacrolimus ointment 0.1% was started, but after a 10-month course of treatment, there was no notable difference in the lesions.

Granuloma faciale (GF) is an uncommon benign dermatosis of unknown pathogenesis characterized by erythematous, brown, or violaceous papules, plaques, or nodules. Granuloma faciale lesions can be solitary or multiple as well as disseminated and most often occur on the face. Predilection sites include the nose, periauricular area, cheeks, forehead, eyelids, and ears; however, lesions also have been reported to occur in extrafacial areas such as the trunk, arms, and legs.^1-4 In our patient, multiple plaques were seen on the scalp. Facial lesions usually precede extrafacial lesions, which may present months to several years after the appearance of facial disease; however, according to our patient's history his scalp lesions appeared before the facial lesions.

The differential diagnoses for GF mainly include erythema elevatum diutinum, cutaneous sarcoidosis, cutaneous lymphoma, lupus, basal cell carcinoma, and cutaneous pseudolymphoma.⁵ Diagnosis may be established based on a combination of clinical features and skin biopsy results. On histopathologic examination, small-vessel vasculitis usually is present with an infiltrate predominantly consisting of neutrophils and eosinophils.⁶

It has been suggested that actinic damage plays a role in the etiology of GF.⁷ The pathogenesis is uncertain, but it is thought that immunophenotypic and molecular analysis of the dermal infiltrate in GF reveals that most lymphocytes are clonally expanded and the process is mediated by interferon gamma.⁷ Tacrolimus acts by binding and inactivating calcineurin and thus blocking T-cell activation and proliferation, so it is not surprising that topical tacrolimus has been shown to be useful in the management of this condition.⁸

The Diagnosis: Granuloma Faciale

A biopsy from a scalp lesion showed an intense mixed inflammatory infiltrate mainly consisting of eosinophils, but lymphocytes, histiocytes, neutrophils, and plasma cells also were present. A grenz zone was observed between the dermal infiltrate and epidermis. Perivascular infiltrates were penetrating vessel walls, and hyalinization of the vessel walls also was seen (Figure 1). Direct immunofluorescence demonstrated IgG positivity on vessel walls (Figure 2). A diagnosis of granuloma faciale with extrafacial lesions was made. Twice daily application of tacrolimus ointment 0.1% was started, but after a 10-month course of treatment, there was no notable difference in the lesions.

Granuloma faciale (GF) is an uncommon benign dermatosis of unknown pathogenesis characterized by erythematous, brown, or violaceous papules, plaques, or nodules. Granuloma faciale lesions can be solitary or multiple as well as disseminated and most often occur on the face. Predilection sites include the nose, periauricular area, cheeks, forehead, eyelids, and ears; however, lesions also have been reported to occur in extrafacial areas such as the trunk, arms, and legs.^1-4 In our patient, multiple plaques were seen on the scalp. Facial lesions usually precede extrafacial lesions, which may present months to several years after the appearance of facial disease; however, according to our patient's history his scalp lesions appeared before the facial lesions.

The differential diagnoses for GF mainly include erythema elevatum diutinum, cutaneous sarcoidosis, cutaneous lymphoma, lupus, basal cell carcinoma, and cutaneous pseudolymphoma.⁵ Diagnosis may be established based on a combination of clinical features and skin biopsy results. On histopathologic examination, small-vessel vasculitis usually is present with an infiltrate predominantly consisting of neutrophils and eosinophils.⁶

It has been suggested that actinic damage plays a role in the etiology of GF.⁷ The pathogenesis is uncertain, but it is thought that immunophenotypic and molecular analysis of the dermal infiltrate in GF reveals that most lymphocytes are clonally expanded and the process is mediated by interferon gamma.⁷ Tacrolimus acts by binding and inactivating calcineurin and thus blocking T-cell activation and proliferation, so it is not surprising that topical tacrolimus has been shown to be useful in the management of this condition.⁸

The Diagnosis: Granuloma Faciale

A biopsy from a scalp lesion showed an intense mixed inflammatory infiltrate mainly consisting of eosinophils, but lymphocytes, histiocytes, neutrophils, and plasma cells also were present. A grenz zone was observed between the dermal infiltrate and epidermis. Perivascular infiltrates were penetrating vessel walls, and hyalinization of the vessel walls also was seen (Figure 1). Direct immunofluorescence demonstrated IgG positivity on vessel walls (Figure 2). A diagnosis of granuloma faciale with extrafacial lesions was made. Twice daily application of tacrolimus ointment 0.1% was started, but after a 10-month course of treatment, there was no notable difference in the lesions.

Granuloma faciale (GF) is an uncommon benign dermatosis of unknown pathogenesis characterized by erythematous, brown, or violaceous papules, plaques, or nodules. Granuloma faciale lesions can be solitary or multiple as well as disseminated and most often occur on the face. Predilection sites include the nose, periauricular area, cheeks, forehead, eyelids, and ears; however, lesions also have been reported to occur in extrafacial areas such as the trunk, arms, and legs.^1-4 In our patient, multiple plaques were seen on the scalp. Facial lesions usually precede extrafacial lesions, which may present months to several years after the appearance of facial disease; however, according to our patient's history his scalp lesions appeared before the facial lesions.

The differential diagnoses for GF mainly include erythema elevatum diutinum, cutaneous sarcoidosis, cutaneous lymphoma, lupus, basal cell carcinoma, and cutaneous pseudolymphoma.⁵ Diagnosis may be established based on a combination of clinical features and skin biopsy results. On histopathologic examination, small-vessel vasculitis usually is present with an infiltrate predominantly consisting of neutrophils and eosinophils.⁶

It has been suggested that actinic damage plays a role in the etiology of GF.⁷ The pathogenesis is uncertain, but it is thought that immunophenotypic and molecular analysis of the dermal infiltrate in GF reveals that most lymphocytes are clonally expanded and the process is mediated by interferon gamma.⁷ Tacrolimus acts by binding and inactivating calcineurin and thus blocking T-cell activation and proliferation, so it is not surprising that topical tacrolimus has been shown to be useful in the management of this condition.⁸

Tranexamic acid is a synthetic lysine derivative that inhibits plasminogen activation by blocking lysine-binding sites on the plasminogen molecule. Although the US Food and Drug Administration–approved indications for tranexamic acid include treatment of patients with menorrhagia and reduction or prevention of hemorrhage in patients with hemophilia undergoing tooth extraction, the potential efficacy of tranexamic acid in the treatment of melasma has been consistently reported since the 1980s.¹

Tranexamic acid exerts effects on pigmentation via its inhibitory effects on UV light–induced plasminogen activator and plasmin activity.² UV radiation induces the synthesis of plasminogen activator by keratinocytes, which results in increased conversion of plasminogen to plasmin. Plasminogen activator induces tyrosinase activity, resulting in increased melanin synthesis. The presence of plasmin results in increased production of both arachidonic acid and fibroblast growth factor, which stimulate melanogenesis and neovascularization, respectively.³ By inhibiting plasminogen activation, tranexamic acid mitigates UV radiation–induced melanogenesis and neovascularization. In treated guinea pig skin, application of topical tranexamic acid following UV radiation exposure inhibited the development of expected skin hyperpigmentation and also reduced tyrosinase activity.^4,5

The largest study on the use of oral tranexamic acid for treatment of melasma was a retrospective chart review of 561 melasma patients treated with tranexamic acid at a single center in Singapore.⁶ More than 90% of patients received prior treatment of their melasma, including bleaching creams and energy-based treatment. Among patients who received oral tranexamic acid over a 4-month period, 90% of patients demonstrated improvement in their melasma severity. Side effects were experienced by 7% of patients; the most common side effects were abdominal bloating and pain (experienced by 2% of patients). Notably, 1 patient developed deep vein thrombosis during treatment and subsequently was found to have protein S deficiency.⁶

Although the daily doses of tranexamic acid for the treatment of menorrhagia and perioperative hemophilia patients are 3900 mg and 30 to 40 mg/kg, respectively, effective daily doses reported for the treatment of melasma have ranged from the initial report of efficacy at 750 to 1500 mg to subsequent reports of improvement at daily doses of 500 mg.^1,2,6-8

Challenges to the use of tranexamic acid for melasma treatment in the United States include the medicolegal environment, specifically the risks associated with using a systemic procoagulant medication for a cosmetic indication. Patients should be screened and counseled on the risks of developing deep vein thrombosis and pulmonary embolism prior to initiating treatment. Cost and accessibility also may limit the use of tranexamic acid in the United States. Tranexamic acid is available for off-label use in the United States with a prescription in the form of 650-mg tablets that can be split by patients to approximate twice-daily 325 mg dosing. This cosmetic indication poses an out-of-pocket cost to patients of over $110 per month or as low as $48 per month with a coupon at the time of publication.⁹

Given the potential for serious adverse effects with the use of systemic tranexamic acid, there has been interest in formulating and evaluating topical tranexamic acid for cosmetic indications.^10-13 Topical tranexamic acid has been used alone and in conjunction with modalities to increase uptake, including intradermal injection, microneedling, and fractionated CO₂ laser.^12-14 Although these reports show initial promise, the currently available data are limited by small sample sizes, short treatment durations, lack of dose comparisons, and lack of short-term or long-term follow-up data. In addition to addressing these knowledge gaps in our understanding of topical tranexamic acid as a treatment option for melasma, further studies on the minimum systemic dose may address the downside of cost and potential for complications that may limit use of this medication in the United States.

The potential uses for tranexamic acid extend to the treatment of postinflammatory hyperpigmentation and rosacea. Melanocytes cultured in media conditioned by fractionated CO₂ laser–treated keratinocytes were found to have decreased tyrosinase activity and reduced melanin content when treated with tranexamic acid, suggesting the potential role for tranexamic acid to be used postprocedurally to reduce the risk for postinflammatory hyperpigmentation in prone skin types.¹⁵ Oral and topical tranexamic acid also have been reported to improve the appearance of erythematotelangiectatic rosacea, potentially relating to the inhibitory effects of tranexamic acid on neovascularization.^3,16,17 Although larger-scale controlled studies are required for further investigation of tranexamic acid for these indications, it has shown early promise as an adjunctive treatment for several dermatologic disorders, including melasma, and warrants further characterization as a potential therapeutic option.

Tranexamic acid is a synthetic lysine derivative that inhibits plasminogen activation by blocking lysine-binding sites on the plasminogen molecule. Although the US Food and Drug Administration–approved indications for tranexamic acid include treatment of patients with menorrhagia and reduction or prevention of hemorrhage in patients with hemophilia undergoing tooth extraction, the potential efficacy of tranexamic acid in the treatment of melasma has been consistently reported since the 1980s.¹

Tranexamic acid exerts effects on pigmentation via its inhibitory effects on UV light–induced plasminogen activator and plasmin activity.² UV radiation induces the synthesis of plasminogen activator by keratinocytes, which results in increased conversion of plasminogen to plasmin. Plasminogen activator induces tyrosinase activity, resulting in increased melanin synthesis. The presence of plasmin results in increased production of both arachidonic acid and fibroblast growth factor, which stimulate melanogenesis and neovascularization, respectively.³ By inhibiting plasminogen activation, tranexamic acid mitigates UV radiation–induced melanogenesis and neovascularization. In treated guinea pig skin, application of topical tranexamic acid following UV radiation exposure inhibited the development of expected skin hyperpigmentation and also reduced tyrosinase activity.^4,5

The largest study on the use of oral tranexamic acid for treatment of melasma was a retrospective chart review of 561 melasma patients treated with tranexamic acid at a single center in Singapore.⁶ More than 90% of patients received prior treatment of their melasma, including bleaching creams and energy-based treatment. Among patients who received oral tranexamic acid over a 4-month period, 90% of patients demonstrated improvement in their melasma severity. Side effects were experienced by 7% of patients; the most common side effects were abdominal bloating and pain (experienced by 2% of patients). Notably, 1 patient developed deep vein thrombosis during treatment and subsequently was found to have protein S deficiency.⁶

Although the daily doses of tranexamic acid for the treatment of menorrhagia and perioperative hemophilia patients are 3900 mg and 30 to 40 mg/kg, respectively, effective daily doses reported for the treatment of melasma have ranged from the initial report of efficacy at 750 to 1500 mg to subsequent reports of improvement at daily doses of 500 mg.^1,2,6-8

Challenges to the use of tranexamic acid for melasma treatment in the United States include the medicolegal environment, specifically the risks associated with using a systemic procoagulant medication for a cosmetic indication. Patients should be screened and counseled on the risks of developing deep vein thrombosis and pulmonary embolism prior to initiating treatment. Cost and accessibility also may limit the use of tranexamic acid in the United States. Tranexamic acid is available for off-label use in the United States with a prescription in the form of 650-mg tablets that can be split by patients to approximate twice-daily 325 mg dosing. This cosmetic indication poses an out-of-pocket cost to patients of over $110 per month or as low as $48 per month with a coupon at the time of publication.⁹

Given the potential for serious adverse effects with the use of systemic tranexamic acid, there has been interest in formulating and evaluating topical tranexamic acid for cosmetic indications.^10-13 Topical tranexamic acid has been used alone and in conjunction with modalities to increase uptake, including intradermal injection, microneedling, and fractionated CO₂ laser.^12-14 Although these reports show initial promise, the currently available data are limited by small sample sizes, short treatment durations, lack of dose comparisons, and lack of short-term or long-term follow-up data. In addition to addressing these knowledge gaps in our understanding of topical tranexamic acid as a treatment option for melasma, further studies on the minimum systemic dose may address the downside of cost and potential for complications that may limit use of this medication in the United States.

The potential uses for tranexamic acid extend to the treatment of postinflammatory hyperpigmentation and rosacea. Melanocytes cultured in media conditioned by fractionated CO₂ laser–treated keratinocytes were found to have decreased tyrosinase activity and reduced melanin content when treated with tranexamic acid, suggesting the potential role for tranexamic acid to be used postprocedurally to reduce the risk for postinflammatory hyperpigmentation in prone skin types.¹⁵ Oral and topical tranexamic acid also have been reported to improve the appearance of erythematotelangiectatic rosacea, potentially relating to the inhibitory effects of tranexamic acid on neovascularization.^3,16,17 Although larger-scale controlled studies are required for further investigation of tranexamic acid for these indications, it has shown early promise as an adjunctive treatment for several dermatologic disorders, including melasma, and warrants further characterization as a potential therapeutic option.

Tranexamic acid is a synthetic lysine derivative that inhibits plasminogen activation by blocking lysine-binding sites on the plasminogen molecule. Although the US Food and Drug Administration–approved indications for tranexamic acid include treatment of patients with menorrhagia and reduction or prevention of hemorrhage in patients with hemophilia undergoing tooth extraction, the potential efficacy of tranexamic acid in the treatment of melasma has been consistently reported since the 1980s.¹

Tranexamic acid exerts effects on pigmentation via its inhibitory effects on UV light–induced plasminogen activator and plasmin activity.² UV radiation induces the synthesis of plasminogen activator by keratinocytes, which results in increased conversion of plasminogen to plasmin. Plasminogen activator induces tyrosinase activity, resulting in increased melanin synthesis. The presence of plasmin results in increased production of both arachidonic acid and fibroblast growth factor, which stimulate melanogenesis and neovascularization, respectively.³ By inhibiting plasminogen activation, tranexamic acid mitigates UV radiation–induced melanogenesis and neovascularization. In treated guinea pig skin, application of topical tranexamic acid following UV radiation exposure inhibited the development of expected skin hyperpigmentation and also reduced tyrosinase activity.^4,5

The largest study on the use of oral tranexamic acid for treatment of melasma was a retrospective chart review of 561 melasma patients treated with tranexamic acid at a single center in Singapore.⁶ More than 90% of patients received prior treatment of their melasma, including bleaching creams and energy-based treatment. Among patients who received oral tranexamic acid over a 4-month period, 90% of patients demonstrated improvement in their melasma severity. Side effects were experienced by 7% of patients; the most common side effects were abdominal bloating and pain (experienced by 2% of patients). Notably, 1 patient developed deep vein thrombosis during treatment and subsequently was found to have protein S deficiency.⁶

Although the daily doses of tranexamic acid for the treatment of menorrhagia and perioperative hemophilia patients are 3900 mg and 30 to 40 mg/kg, respectively, effective daily doses reported for the treatment of melasma have ranged from the initial report of efficacy at 750 to 1500 mg to subsequent reports of improvement at daily doses of 500 mg.^1,2,6-8

Challenges to the use of tranexamic acid for melasma treatment in the United States include the medicolegal environment, specifically the risks associated with using a systemic procoagulant medication for a cosmetic indication. Patients should be screened and counseled on the risks of developing deep vein thrombosis and pulmonary embolism prior to initiating treatment. Cost and accessibility also may limit the use of tranexamic acid in the United States. Tranexamic acid is available for off-label use in the United States with a prescription in the form of 650-mg tablets that can be split by patients to approximate twice-daily 325 mg dosing. This cosmetic indication poses an out-of-pocket cost to patients of over $110 per month or as low as $48 per month with a coupon at the time of publication.⁹

Given the potential for serious adverse effects with the use of systemic tranexamic acid, there has been interest in formulating and evaluating topical tranexamic acid for cosmetic indications.^10-13 Topical tranexamic acid has been used alone and in conjunction with modalities to increase uptake, including intradermal injection, microneedling, and fractionated CO₂ laser.^12-14 Although these reports show initial promise, the currently available data are limited by small sample sizes, short treatment durations, lack of dose comparisons, and lack of short-term or long-term follow-up data. In addition to addressing these knowledge gaps in our understanding of topical tranexamic acid as a treatment option for melasma, further studies on the minimum systemic dose may address the downside of cost and potential for complications that may limit use of this medication in the United States.

The potential uses for tranexamic acid extend to the treatment of postinflammatory hyperpigmentation and rosacea. Melanocytes cultured in media conditioned by fractionated CO₂ laser–treated keratinocytes were found to have decreased tyrosinase activity and reduced melanin content when treated with tranexamic acid, suggesting the potential role for tranexamic acid to be used postprocedurally to reduce the risk for postinflammatory hyperpigmentation in prone skin types.¹⁵ Oral and topical tranexamic acid also have been reported to improve the appearance of erythematotelangiectatic rosacea, potentially relating to the inhibitory effects of tranexamic acid on neovascularization.^3,16,17 Although larger-scale controlled studies are required for further investigation of tranexamic acid for these indications, it has shown early promise as an adjunctive treatment for several dermatologic disorders, including melasma, and warrants further characterization as a potential therapeutic option.

Myth: Wearing makeup causes acne breakouts

Acne breakouts caused by makeup and other skin care products, known as acne cosmetica, typically resolve when patients stop using pore-clogging products; however, the overall impact of cosmetics on the development of acne lesions is considered to be negligible. Many cosmetics are not inherently comedogenic and can be used safely by patients in combination with proper skin care techniques.

Although dermatologists may be inclined to discourage makeup use during acne treatment or breakouts due to its potential to aggravate the patient’s condition, research has shown that treatment results and quality of life (QoL) scores associated with makeup use in acne patients may improve when patients receive instruction on how to use skin care products and cosmetics effectively. In one study of 50 female acne patients, 25 participants were instructed on how to use skin care products and cosmetics, and the other 25 participants received no specific instructions from dermatologists. After 4 weeks of treatment with conventional topical and/or oral acne medications, the investigators concluded that use of skin care products did not negatively impact acne treatment, and the group that received application instructions showed more notable improvements in QoL scores versus those who did not. In another study, the overall number of acne eruptions decreased over a 2- to 4-week period in female acne patients who were trained by a makeup artist to apply cosmetics while undergoing acne treatment. These results suggest that acne patients who wear makeup may benefit from a conversation with their dermatologist about what products and skin care techniques they can use to minimize exacerbation of or even improve their condition.

When choosing makeup that will not cause or exacerbate acne breakouts, patients should look for packaging that indicates the product will not clog pores and is oil-free, noncomedogenic, and/or nonacnegenic. Some makeup products are specifically formulated to help camouflage redness and pimples, which can help improve quality of life and self-esteem in acne patients who otherwise may be self-conscious about their appearance. Mineral-based cosmetics containing powdered formulas of silica, titanium dioxide, and zinc oxide can be used to absorb oil, camouflage redness, and prevent irritation. Anti-inflammatory ingredients and antioxidants also are used in some makeup products to reduce skin irritation and promote barrier repair. Additional cosmetic ingredients that can affect the mechanisms of acne pathogenesis and may contribute to a decrease in acne lesions include nicotinamide, lactic acid, triethyl acetate/ethyllineolate, and prebiotic plant extracts.

Makeup should be applied gently to avoid irritating the skin. It also is important to remind patients not to share their makeup brushes and applicators and to clean them weekly to ensure that bacteria, dead skin cells, and oil are not spread to the skin, which can lead to new breakouts. Although patients may be compelled to scrub the skin to remove makeup, a mild cleanser should be gently applied using the fingertips and rinsed off with lukewarm water to minimize skin irritation. Any makeup remaining on the skin after washing should be gently removed with an oil-free makeup remover.
 

Myth: Wearing makeup causes acne breakouts

Acne breakouts caused by makeup and other skin care products, known as acne cosmetica, typically resolve when patients stop using pore-clogging products; however, the overall impact of cosmetics on the development of acne lesions is considered to be negligible. Many cosmetics are not inherently comedogenic and can be used safely by patients in combination with proper skin care techniques.

Although dermatologists may be inclined to discourage makeup use during acne treatment or breakouts due to its potential to aggravate the patient’s condition, research has shown that treatment results and quality of life (QoL) scores associated with makeup use in acne patients may improve when patients receive instruction on how to use skin care products and cosmetics effectively. In one study of 50 female acne patients, 25 participants were instructed on how to use skin care products and cosmetics, and the other 25 participants received no specific instructions from dermatologists. After 4 weeks of treatment with conventional topical and/or oral acne medications, the investigators concluded that use of skin care products did not negatively impact acne treatment, and the group that received application instructions showed more notable improvements in QoL scores versus those who did not. In another study, the overall number of acne eruptions decreased over a 2- to 4-week period in female acne patients who were trained by a makeup artist to apply cosmetics while undergoing acne treatment. These results suggest that acne patients who wear makeup may benefit from a conversation with their dermatologist about what products and skin care techniques they can use to minimize exacerbation of or even improve their condition.

When choosing makeup that will not cause or exacerbate acne breakouts, patients should look for packaging that indicates the product will not clog pores and is oil-free, noncomedogenic, and/or nonacnegenic. Some makeup products are specifically formulated to help camouflage redness and pimples, which can help improve quality of life and self-esteem in acne patients who otherwise may be self-conscious about their appearance. Mineral-based cosmetics containing powdered formulas of silica, titanium dioxide, and zinc oxide can be used to absorb oil, camouflage redness, and prevent irritation. Anti-inflammatory ingredients and antioxidants also are used in some makeup products to reduce skin irritation and promote barrier repair. Additional cosmetic ingredients that can affect the mechanisms of acne pathogenesis and may contribute to a decrease in acne lesions include nicotinamide, lactic acid, triethyl acetate/ethyllineolate, and prebiotic plant extracts.

Makeup should be applied gently to avoid irritating the skin. It also is important to remind patients not to share their makeup brushes and applicators and to clean them weekly to ensure that bacteria, dead skin cells, and oil are not spread to the skin, which can lead to new breakouts. Although patients may be compelled to scrub the skin to remove makeup, a mild cleanser should be gently applied using the fingertips and rinsed off with lukewarm water to minimize skin irritation. Any makeup remaining on the skin after washing should be gently removed with an oil-free makeup remover.
 

Myth: Wearing makeup causes acne breakouts

Acne breakouts caused by makeup and other skin care products, known as acne cosmetica, typically resolve when patients stop using pore-clogging products; however, the overall impact of cosmetics on the development of acne lesions is considered to be negligible. Many cosmetics are not inherently comedogenic and can be used safely by patients in combination with proper skin care techniques.

Although dermatologists may be inclined to discourage makeup use during acne treatment or breakouts due to its potential to aggravate the patient’s condition, research has shown that treatment results and quality of life (QoL) scores associated with makeup use in acne patients may improve when patients receive instruction on how to use skin care products and cosmetics effectively. In one study of 50 female acne patients, 25 participants were instructed on how to use skin care products and cosmetics, and the other 25 participants received no specific instructions from dermatologists. After 4 weeks of treatment with conventional topical and/or oral acne medications, the investigators concluded that use of skin care products did not negatively impact acne treatment, and the group that received application instructions showed more notable improvements in QoL scores versus those who did not. In another study, the overall number of acne eruptions decreased over a 2- to 4-week period in female acne patients who were trained by a makeup artist to apply cosmetics while undergoing acne treatment. These results suggest that acne patients who wear makeup may benefit from a conversation with their dermatologist about what products and skin care techniques they can use to minimize exacerbation of or even improve their condition.

When choosing makeup that will not cause or exacerbate acne breakouts, patients should look for packaging that indicates the product will not clog pores and is oil-free, noncomedogenic, and/or nonacnegenic. Some makeup products are specifically formulated to help camouflage redness and pimples, which can help improve quality of life and self-esteem in acne patients who otherwise may be self-conscious about their appearance. Mineral-based cosmetics containing powdered formulas of silica, titanium dioxide, and zinc oxide can be used to absorb oil, camouflage redness, and prevent irritation. Anti-inflammatory ingredients and antioxidants also are used in some makeup products to reduce skin irritation and promote barrier repair. Additional cosmetic ingredients that can affect the mechanisms of acne pathogenesis and may contribute to a decrease in acne lesions include nicotinamide, lactic acid, triethyl acetate/ethyllineolate, and prebiotic plant extracts.

Makeup should be applied gently to avoid irritating the skin. It also is important to remind patients not to share their makeup brushes and applicators and to clean them weekly to ensure that bacteria, dead skin cells, and oil are not spread to the skin, which can lead to new breakouts. Although patients may be compelled to scrub the skin to remove makeup, a mild cleanser should be gently applied using the fingertips and rinsed off with lukewarm water to minimize skin irritation. Any makeup remaining on the skin after washing should be gently removed with an oil-free makeup remover.
 

The Diagnosis: Hypopigmented Mycosis Fungoides

The patient was started on clobetasol dipropionate cream 0.05% twice daily, which she did not tolerate due to a burning sensation on application. She then was started on narrowband UVB phototherapy 2 to 3 times weekly, and the hypopigmented areas began to improve. Narrowband UVB phototherapy was discontinued after 7 weeks due to the high cost to the patient, but the hypopigmented patches on the left thigh appeared to remit, and the patient did not return to the clinic for 6 months. She returned when the areas on the left thigh reappeared, along with new areas on the right buttock and right medial upper arm. Serial biopsies of the new patches also revealed a CD8⁺ atypical lymphocytic infiltrate consistent with hypopigmented patch-stage mycosis fungoides (MF). She was started on halobetasol ointment 0.05% twice daily to affected areas, which she tolerated well. Complete blood count and peripheral blood smear were unremarkable, and the patient continued to deny systemic symptoms. Over the next year, the patient's cutaneous findings continued to wax and wane with topical treatment, and she was referred to a regional cancer treatment center for a second opinion from a hematopathologist. Hematopathologic and dermatopathologic review of the case, including hematoxylin and eosin and immunohistochemical staining, was highly consistent with hypopigmented MF (Figures 1-3).

Mycosis fungoides is an uncommon disease characterized by atypical clonal T cells exhibiting epidermotropism. Most commonly, MF is characterized by a CD4⁺ lymphocytic infiltrate. Mycosis fungoides can be difficult to diagnose in its early stages, as it may resemble benign inflammatory conditions (eg, chronic atopic dermatitis, nummular eczema) and often requires biopsy and additional studies, such as immunohistochemistry, to secure a diagnosis. Hypopigmented MF is regarded as a subtype of MF, as it can exhibit different clinical and pathologic characteristics from classical MF. In particular, the lymphocytic phenotype in hypopigmented MF is more likely to be CD8⁺. 

In general, the progression of MF is characterized as stage IA (patches or plaques involving less than 10% body surface area [BSA]), IB (patches or plaques involving ≥10% BSA without lymph node or visceral involvement), IIA (patches or plaques of any percentage of BSA with lymph node involvement), IIB (cutaneous tumors with or without lymph node involvement), III (erythroderma with low blood tumor burden), or IV (erythroderma with high blood tumor burden with or without visceral involvement). Hypopigmented MF generally presents in early patch stage and rarely progresses past stage IB, and thus generally has a favorable prognosis.^1,2 Kim et al³ demonstrated that evolution from patch to plaque stage MF is accompanied by a shift in lymphocytes from the T helper 1 (Th1) to T helper 2 phenotype; therefore the Th1 phenotype, CD8⁺ T cells are associated with lower risk for disease progression. Other investigators also have hypothesized that predominance of Th1 phenotype, CD8⁺ T cells may have an immunoregulatory effect, thus preventing evolution of disease from patch to plaque stage and explaining why hypopigmented MF, with a predominantly CD8⁺ phenotype, confers better prognosis with less chance for disease progression than classical MF.^4,5 The patch- or plaque-stage lesions of classical MF have a predilection for non-sun exposed areas (eg, buttocks, medial thighs, breasts),² whereas hypopigmented MF tends to present with hypopigmented or depigmented lesions mainly distributed on the trunk, arms, and legs. These lesions may become more visible following sun exposure.¹ The size of the hypopigmented lesions can vary, and patients may complain of pruritus with variable intensity.

Hypopigmented MF presents more commonly in younger populations, in contrast to classical MF.^6-8 However, like classical MF, hypopigmented MF appears to more frequently affect individuals with darker Fitzpatrick skin types.^1,9,10 Although it generally is accepted that hypopigmented MF does not favor either sex, some studies suggest that hypopigmented MF has a female predominance.^6,10

Classical MF is characterized by an epidermotropic infiltrate of CD4⁺ T helper cells,¹⁰ whereas CD8⁺ epidermotropism is considered hallmark in hypopigmented MF.^10-12 The other typical histopathologic features of hypopigmented MF generally are identical to those of classical MF, with solitary or small groups of atypical haloed lymphocytes within the basal layer, exocytosis of lymphocytes out of proportion to spongiosis, and papillary dermal fibrosis. Immunohistochemistry generally is helpful in distinguishing between classical MF and hypopigmented MF.

The clinical differential diagnosis for hypopigmented MF includes the early (inflammatory) stage of vitiligo, postinflammatory hypopigmentation, lichen sclerosus, pityriasis alba, and leprosy.

First-line treatment for hypopigmented MF consists of phototherapy/photochemotherapy and topical steroids.^9,13 Narrowband UVB phototherapy has been used with good success in pediatric patients.¹⁴ However, narrowband UVB may not be as effective in darker-skinned individuals; it has been hypothesized that this lack of efficacy could be due to the protective effects of increased melanin in the skin.¹ Other topical therapies may include topical carmustine and topical nitrogen mustard.

The Diagnosis: Hypopigmented Mycosis Fungoides

The patient was started on clobetasol dipropionate cream 0.05% twice daily, which she did not tolerate due to a burning sensation on application. She then was started on narrowband UVB phototherapy 2 to 3 times weekly, and the hypopigmented areas began to improve. Narrowband UVB phototherapy was discontinued after 7 weeks due to the high cost to the patient, but the hypopigmented patches on the left thigh appeared to remit, and the patient did not return to the clinic for 6 months. She returned when the areas on the left thigh reappeared, along with new areas on the right buttock and right medial upper arm. Serial biopsies of the new patches also revealed a CD8⁺ atypical lymphocytic infiltrate consistent with hypopigmented patch-stage mycosis fungoides (MF). She was started on halobetasol ointment 0.05% twice daily to affected areas, which she tolerated well. Complete blood count and peripheral blood smear were unremarkable, and the patient continued to deny systemic symptoms. Over the next year, the patient's cutaneous findings continued to wax and wane with topical treatment, and she was referred to a regional cancer treatment center for a second opinion from a hematopathologist. Hematopathologic and dermatopathologic review of the case, including hematoxylin and eosin and immunohistochemical staining, was highly consistent with hypopigmented MF (Figures 1-3).

Mycosis fungoides is an uncommon disease characterized by atypical clonal T cells exhibiting epidermotropism. Most commonly, MF is characterized by a CD4⁺ lymphocytic infiltrate. Mycosis fungoides can be difficult to diagnose in its early stages, as it may resemble benign inflammatory conditions (eg, chronic atopic dermatitis, nummular eczema) and often requires biopsy and additional studies, such as immunohistochemistry, to secure a diagnosis. Hypopigmented MF is regarded as a subtype of MF, as it can exhibit different clinical and pathologic characteristics from classical MF. In particular, the lymphocytic phenotype in hypopigmented MF is more likely to be CD8⁺. 

In general, the progression of MF is characterized as stage IA (patches or plaques involving less than 10% body surface area [BSA]), IB (patches or plaques involving ≥10% BSA without lymph node or visceral involvement), IIA (patches or plaques of any percentage of BSA with lymph node involvement), IIB (cutaneous tumors with or without lymph node involvement), III (erythroderma with low blood tumor burden), or IV (erythroderma with high blood tumor burden with or without visceral involvement). Hypopigmented MF generally presents in early patch stage and rarely progresses past stage IB, and thus generally has a favorable prognosis.^1,2 Kim et al³ demonstrated that evolution from patch to plaque stage MF is accompanied by a shift in lymphocytes from the T helper 1 (Th1) to T helper 2 phenotype; therefore the Th1 phenotype, CD8⁺ T cells are associated with lower risk for disease progression. Other investigators also have hypothesized that predominance of Th1 phenotype, CD8⁺ T cells may have an immunoregulatory effect, thus preventing evolution of disease from patch to plaque stage and explaining why hypopigmented MF, with a predominantly CD8⁺ phenotype, confers better prognosis with less chance for disease progression than classical MF.^4,5 The patch- or plaque-stage lesions of classical MF have a predilection for non-sun exposed areas (eg, buttocks, medial thighs, breasts),² whereas hypopigmented MF tends to present with hypopigmented or depigmented lesions mainly distributed on the trunk, arms, and legs. These lesions may become more visible following sun exposure.¹ The size of the hypopigmented lesions can vary, and patients may complain of pruritus with variable intensity.

Hypopigmented MF presents more commonly in younger populations, in contrast to classical MF.^6-8 However, like classical MF, hypopigmented MF appears to more frequently affect individuals with darker Fitzpatrick skin types.^1,9,10 Although it generally is accepted that hypopigmented MF does not favor either sex, some studies suggest that hypopigmented MF has a female predominance.^6,10

Classical MF is characterized by an epidermotropic infiltrate of CD4⁺ T helper cells,¹⁰ whereas CD8⁺ epidermotropism is considered hallmark in hypopigmented MF.^10-12 The other typical histopathologic features of hypopigmented MF generally are identical to those of classical MF, with solitary or small groups of atypical haloed lymphocytes within the basal layer, exocytosis of lymphocytes out of proportion to spongiosis, and papillary dermal fibrosis. Immunohistochemistry generally is helpful in distinguishing between classical MF and hypopigmented MF.

The clinical differential diagnosis for hypopigmented MF includes the early (inflammatory) stage of vitiligo, postinflammatory hypopigmentation, lichen sclerosus, pityriasis alba, and leprosy.

First-line treatment for hypopigmented MF consists of phototherapy/photochemotherapy and topical steroids.^9,13 Narrowband UVB phototherapy has been used with good success in pediatric patients.¹⁴ However, narrowband UVB may not be as effective in darker-skinned individuals; it has been hypothesized that this lack of efficacy could be due to the protective effects of increased melanin in the skin.¹ Other topical therapies may include topical carmustine and topical nitrogen mustard.

The Diagnosis: Hypopigmented Mycosis Fungoides

The patient was started on clobetasol dipropionate cream 0.05% twice daily, which she did not tolerate due to a burning sensation on application. She then was started on narrowband UVB phototherapy 2 to 3 times weekly, and the hypopigmented areas began to improve. Narrowband UVB phototherapy was discontinued after 7 weeks due to the high cost to the patient, but the hypopigmented patches on the left thigh appeared to remit, and the patient did not return to the clinic for 6 months. She returned when the areas on the left thigh reappeared, along with new areas on the right buttock and right medial upper arm. Serial biopsies of the new patches also revealed a CD8⁺ atypical lymphocytic infiltrate consistent with hypopigmented patch-stage mycosis fungoides (MF). She was started on halobetasol ointment 0.05% twice daily to affected areas, which she tolerated well. Complete blood count and peripheral blood smear were unremarkable, and the patient continued to deny systemic symptoms. Over the next year, the patient's cutaneous findings continued to wax and wane with topical treatment, and she was referred to a regional cancer treatment center for a second opinion from a hematopathologist. Hematopathologic and dermatopathologic review of the case, including hematoxylin and eosin and immunohistochemical staining, was highly consistent with hypopigmented MF (Figures 1-3).

Mycosis fungoides is an uncommon disease characterized by atypical clonal T cells exhibiting epidermotropism. Most commonly, MF is characterized by a CD4⁺ lymphocytic infiltrate. Mycosis fungoides can be difficult to diagnose in its early stages, as it may resemble benign inflammatory conditions (eg, chronic atopic dermatitis, nummular eczema) and often requires biopsy and additional studies, such as immunohistochemistry, to secure a diagnosis. Hypopigmented MF is regarded as a subtype of MF, as it can exhibit different clinical and pathologic characteristics from classical MF. In particular, the lymphocytic phenotype in hypopigmented MF is more likely to be CD8⁺. 

In general, the progression of MF is characterized as stage IA (patches or plaques involving less than 10% body surface area [BSA]), IB (patches or plaques involving ≥10% BSA without lymph node or visceral involvement), IIA (patches or plaques of any percentage of BSA with lymph node involvement), IIB (cutaneous tumors with or without lymph node involvement), III (erythroderma with low blood tumor burden), or IV (erythroderma with high blood tumor burden with or without visceral involvement). Hypopigmented MF generally presents in early patch stage and rarely progresses past stage IB, and thus generally has a favorable prognosis.^1,2 Kim et al³ demonstrated that evolution from patch to plaque stage MF is accompanied by a shift in lymphocytes from the T helper 1 (Th1) to T helper 2 phenotype; therefore the Th1 phenotype, CD8⁺ T cells are associated with lower risk for disease progression. Other investigators also have hypothesized that predominance of Th1 phenotype, CD8⁺ T cells may have an immunoregulatory effect, thus preventing evolution of disease from patch to plaque stage and explaining why hypopigmented MF, with a predominantly CD8⁺ phenotype, confers better prognosis with less chance for disease progression than classical MF.^4,5 The patch- or plaque-stage lesions of classical MF have a predilection for non-sun exposed areas (eg, buttocks, medial thighs, breasts),² whereas hypopigmented MF tends to present with hypopigmented or depigmented lesions mainly distributed on the trunk, arms, and legs. These lesions may become more visible following sun exposure.¹ The size of the hypopigmented lesions can vary, and patients may complain of pruritus with variable intensity.

Hypopigmented MF presents more commonly in younger populations, in contrast to classical MF.^6-8 However, like classical MF, hypopigmented MF appears to more frequently affect individuals with darker Fitzpatrick skin types.^1,9,10 Although it generally is accepted that hypopigmented MF does not favor either sex, some studies suggest that hypopigmented MF has a female predominance.^6,10

Classical MF is characterized by an epidermotropic infiltrate of CD4⁺ T helper cells,¹⁰ whereas CD8⁺ epidermotropism is considered hallmark in hypopigmented MF.^10-12 The other typical histopathologic features of hypopigmented MF generally are identical to those of classical MF, with solitary or small groups of atypical haloed lymphocytes within the basal layer, exocytosis of lymphocytes out of proportion to spongiosis, and papillary dermal fibrosis. Immunohistochemistry generally is helpful in distinguishing between classical MF and hypopigmented MF.

The clinical differential diagnosis for hypopigmented MF includes the early (inflammatory) stage of vitiligo, postinflammatory hypopigmentation, lichen sclerosus, pityriasis alba, and leprosy.

First-line treatment for hypopigmented MF consists of phototherapy/photochemotherapy and topical steroids.^9,13 Narrowband UVB phototherapy has been used with good success in pediatric patients.¹⁴ However, narrowband UVB may not be as effective in darker-skinned individuals; it has been hypothesized that this lack of efficacy could be due to the protective effects of increased melanin in the skin.¹ Other topical therapies may include topical carmustine and topical nitrogen mustard.