David Jackson, MPAS, PA-C

A 65-year-old man presented to the emergency department (ED) with a two-week history of progressively severe pain in his right hand and difficulty moving his fingers. He reported that approximately two weeks earlier, while shoveling snow, he slipped and fell, landing on his right hand. Initially, he had no problems with his hand. He finished his shoveling and continued his normal daily activities.

Within two to three days he started to experience pain in his right hand, which grew progressively worse.

Because he did not have a primary care provider, the patient had a limited medical history. He reported having a mildly elevated prostate-specific antigen test years earlier. He underwent an appendectomy at age 15. He denied any other medical problems.

The patient was taking no medications and reported no known allergies to medications. He denied the use of tobacco, said he had one or two beers on an average day, and denied IV drug use. He was an artist and was married with one adult child. His family history was unremarkable with the exception of an alcoholic sister who died of cirrhosis at age 70.

During triage, vital signs were essentially normal: blood pressure, 142/74 mm Hg; heart rate, 78 beats/min; and respiratory rate, 20 breaths/min. The patient was afebrile at 37.2°C (98.9°F). Physical examination was remarkable for some edema and warmth of the right hand without any notable erythema. There was no evidence of any wound. Fingers all had good sensation; however, flexion of the index and long fingers elicited a significant increase in pain.

The remainder of the exam was unremarkable. The patient’s head was normocephalic and atraumatic. Pupils were equal, round, and reactive to light. Eyes were anicteric, and no rhinorrhea was evident. The neck was supple without palpable lymphadenopathy. Lungs were clear to auscultation bilaterally. No wheezes, rales, or rhonchi were appreciated. The heart had a regular rate and rhythm; no murmurs, rubs, or gallups were noted. The abdomen was soft and non-tender. The extremities, except as previously stated, were normal, with good pulses, sensation, and strength.

Initially, only radiographs of the right hand were ordered (see Figures 1 and 2). These demonstrated soft tissue swelling on the dorsum of the hand, and an area of hypodensity between the first and second metacarpals. There were no fractures, dislocations, or other bone or joint abnormalities.

After a review of the radiographs, it was clear that the patient’s diagnosis was not a simple answer of hand contusion or fracture; thus, the evaluation was expanded. Vital signs were repeated three hours after triage: blood pressure, 128/74 mm Hg; heart rate, 76 beats/min; and respiration, 20 breaths/min. The patient was now febrile at 37.6°C (99.7°F). Because of his fever and the anomaly on the patient’s hand radiograph, expansion of the evaluation continued.

Laboratory studies included a complete blood count: white blood cells (WBCs), 30,700/mcL (reference range,¹ 4,500 to 11,000/mcL); hemoglobin, 13.3 g/dL (13.8 to 17.2 g/dL for men); hematocrit, 40.0% (41% to 50% for men); platelets, 217,000/mcL (130 to 400 x 10³/mcL). Initial chemistry panel results were normal except for serum glucose, 143 mg/dL (70 to 125 mg/dL).

Liver function test results were normal except for aspartate aminotransferase, 33 U/L (reference range,¹ 10 to 30 U/L) and albumin, 2.5 g/dL (3.5 to 5.0 g/dL). Once WBCs were found to exceed 30,000/mcL, the search for a cause was widened once more.

The continued studies included a chest radiograph with normal results, unremarkable CT of the abdomen and pelvis with IV contrast, blood cultures, and urinalysis. The urinalysis showed: blood, moderate; protein, trace; nitrites, positive; leukocytes, large; WBCs > 50/high-power field (reference range,¹ 5/high-power field or less); and numerous bacteria.

The final study performed in the ED evaluation of the patient was a CT of the right hand with IV contrast (see Figure 3). It demonstrated diffuse edema and a 9.0-mm area of low attenuation with some rim enhancement. The differential for these findings includes an abscess or a foreign body; the latter was deemed unlikely in light of the patient’s physical exam. In consideration of his elevated WBC count, the high number of WBCs in his urine, the fever, and the CT results, the patient was diagnosed with an abscess in his right hand that had been seeded, it was surmised, by an occult urosepsis after his fall.

Before the patient’s admission, a hand surgeon was consulted. The surgeon agreed with the diagnosis, and the patient was taken to the operating room (OR). He had been given piperacillin/tazobactam in the ED.

In the OR, the surgeon made a 3.0-cm incision, conducted an exploration, and identified a cavity that contained a small amount of purulence. He determined the lesion to be a resolving abscess. The wound was washed out, and the area was closed with a Penrose drain.

The patient was continued on the piperacillin/tazobactam. His blood culture was positive for gram-positive rods, and a low-grade fever persisted. An infectious disease specialist was consulted, and levofloxacin was added to the patient’s regimen.

After 24 hours of treatment, findings on urinalysis improved: blood, small; protein, trace; nitrites, negative; leukocytes, small; WBCs, 15 to 20/high-power field; and no bacteria. Over the next three days, the patient’s condition continued to improve. His hand drain was removed, and the pain and swelling subsided. He became afebrile, and his WBC count fell to 24,700/mcL. He was discharged to home with prescriptions for cephalexin and levofloxacin. Follow-up for postoperative care was arranged with the hand surgeon.

Discussion
Pyomyositis is defined as abscess formation deep within large striated muscles.¹ Although this condition is uncommon, it is believed that an occult bacteremia can seed an area of damaged muscle (compared with healthy muscle, which ordinarily resists infection), allowing an abscess to form.^1,2

Epidemiology
In a 2002 review involving 676 patients with primary pyomyositis, Bickels et al³ reported the condition in ages ranging from two months to 82 years (mean, 28.1 years). In a majority of cases, only a single muscle was involved; 112 patients (16.6%) were identified with multiple-site involvement. Only seven cases (0.1%) involved the hand.

In 452 cases (66.9%), a bacterial agent was identified. Among these, 350 (77%) had a positive culture for Staphylococcus aureus. Other isolates included Streptococcus pyogenes, Escherichia coli, Salmonella enteritidus, and Mycobacterium tuberculosis.^1,3 It should be noted that community-­acquired methicillin-resistant S aureus (CA-MRSA) is being implicated with increasing frequency in cases of pyomyositis.^4-6

Because pyomyositis is not a reportable disease and has not been studied in large clinical trials, its incidence is uncertain, and proposed risk factors have not all been confirmed² (see Table^2,7).

Pathophysiology
While the etiology of primary pyomyositis is unclear, it is believed to be caused by a combination of bacteremia (chronic or transient) and damaged muscle. In a 1960 study published in the Lancet, Smith and Vickers⁸ performed autopsies on 327 patients who had died of culture-positive septicemia. Only two patients were found to have a muscle abscess. At that time, the investigators concluded that both muscle injury and bacteremia would need to be present in order for an abscess to form. In animal studies, bacteremia (eg, S aureus) does not appear to lead to pyomyositis except in cases of muscle abnormality or trauma (eg, electric shock, pinching injury).^9,10

When a history of trauma can be identified in patients with pyomyositis, the condition typically develops near the affected muscle, and the infection appears within days to weeks.3 In cases in which an antecedent infection is identified and hematogenous spread of the bacteria to the skeletal muscle occurs, this is termed secondary pyomyositis.¹¹

Disease Progression
Pyomyositis generally progresses in three stages, beginning with inflammation and advancing to a focal abscess, then to a septic state.³ The first stage develops between seven and 21 days after the initial incident, is typically subacute, involves mild pain and swelling with a “woody” texture, and is occasionally associated with fevers.²

Diagnosis of pyomyositis is usually made during the second stage, 10 to 21 days after the initial incident; by that time, the pain has increased, and the fever is more pronounced. Third-stage infection usually involves fluctuance and sepsis.²

Although MRI is considered most useful in the diagnosis of pyomyositis, CT and ultrasound allow for percutaneous needle aspiration and drainage.³

Treatment
The correct treatment for pyomyositis depends upon the stage at which the disease is identified. During the first stage (before formation of an abscess), antibiotic treatment alone may be sufficient.¹ Once an abscess has formed, an incision and drainage will be required, in conjunction with or followed by appropriate antibiotic therapy.

When pyomyositis is properly treated during the first or second stage, a full recovery is likely.^2,3 By the third stage, surgical debridement is required. Additionally, osteomyelitis may develop in the adjacent bones, followed by muscle scarring, residual weakness, and functional impairment.^2,3 Reported pyomyositis-associated mortality ranges between less than 1% and 4%.^2,12

The Case Patient

The case presented here was of particular interest for two reasons. First, the patient had a traumatic injury that initially caused him no concern but worsened progressively over 14 days. Although this is not the typical presentation of a traumatic injury, the ED staff could very easily have performed a radiograph, made a diagnosis of traumatic hand injury, and discharged the patient.

Second, men in their 60s do not commonly have urinary tract infections.¹³ The patient was questioned frequently by several providers about sexual behaviors, medical problems, and urinary symptoms. Repeatedly, he denied all of these issues. While a urinalysis may be omitted in the evaluation of an otherwise healthy, asymptomatic patient, its results in this case were a key piece of data.

It should be noted that the patient thought it inappropriate to be asked for urine samples. He repeatedly said, “It’s my hand!”

Conclusion
Even in patients presenting with the most routine complaint, a careful evaluation can reveal unexpected, serious problems. This patient complained of pain in his hand some time after a fall and ultimately was treated for an occult urosepsis and hand abscess—pyomyositis, which rarely occurs in small muscles, such as those of the hand. Either condition, left untreated, could have led to serious morbidity or even mortality.

A 65-year-old man presented to the emergency department (ED) with a two-week history of progressively severe pain in his right hand and difficulty moving his fingers. He reported that approximately two weeks earlier, while shoveling snow, he slipped and fell, landing on his right hand. Initially, he had no problems with his hand. He finished his shoveling and continued his normal daily activities.

Within two to three days he started to experience pain in his right hand, which grew progressively worse.

Because he did not have a primary care provider, the patient had a limited medical history. He reported having a mildly elevated prostate-specific antigen test years earlier. He underwent an appendectomy at age 15. He denied any other medical problems.

The patient was taking no medications and reported no known allergies to medications. He denied the use of tobacco, said he had one or two beers on an average day, and denied IV drug use. He was an artist and was married with one adult child. His family history was unremarkable with the exception of an alcoholic sister who died of cirrhosis at age 70.

During triage, vital signs were essentially normal: blood pressure, 142/74 mm Hg; heart rate, 78 beats/min; and respiratory rate, 20 breaths/min. The patient was afebrile at 37.2°C (98.9°F). Physical examination was remarkable for some edema and warmth of the right hand without any notable erythema. There was no evidence of any wound. Fingers all had good sensation; however, flexion of the index and long fingers elicited a significant increase in pain.

The remainder of the exam was unremarkable. The patient’s head was normocephalic and atraumatic. Pupils were equal, round, and reactive to light. Eyes were anicteric, and no rhinorrhea was evident. The neck was supple without palpable lymphadenopathy. Lungs were clear to auscultation bilaterally. No wheezes, rales, or rhonchi were appreciated. The heart had a regular rate and rhythm; no murmurs, rubs, or gallups were noted. The abdomen was soft and non-tender. The extremities, except as previously stated, were normal, with good pulses, sensation, and strength.

Initially, only radiographs of the right hand were ordered (see Figures 1 and 2). These demonstrated soft tissue swelling on the dorsum of the hand, and an area of hypodensity between the first and second metacarpals. There were no fractures, dislocations, or other bone or joint abnormalities.

After a review of the radiographs, it was clear that the patient’s diagnosis was not a simple answer of hand contusion or fracture; thus, the evaluation was expanded. Vital signs were repeated three hours after triage: blood pressure, 128/74 mm Hg; heart rate, 76 beats/min; and respiration, 20 breaths/min. The patient was now febrile at 37.6°C (99.7°F). Because of his fever and the anomaly on the patient’s hand radiograph, expansion of the evaluation continued.

Laboratory studies included a complete blood count: white blood cells (WBCs), 30,700/mcL (reference range,¹ 4,500 to 11,000/mcL); hemoglobin, 13.3 g/dL (13.8 to 17.2 g/dL for men); hematocrit, 40.0% (41% to 50% for men); platelets, 217,000/mcL (130 to 400 x 10³/mcL). Initial chemistry panel results were normal except for serum glucose, 143 mg/dL (70 to 125 mg/dL).

Liver function test results were normal except for aspartate aminotransferase, 33 U/L (reference range,¹ 10 to 30 U/L) and albumin, 2.5 g/dL (3.5 to 5.0 g/dL). Once WBCs were found to exceed 30,000/mcL, the search for a cause was widened once more.

The continued studies included a chest radiograph with normal results, unremarkable CT of the abdomen and pelvis with IV contrast, blood cultures, and urinalysis. The urinalysis showed: blood, moderate; protein, trace; nitrites, positive; leukocytes, large; WBCs > 50/high-power field (reference range,¹ 5/high-power field or less); and numerous bacteria.

The final study performed in the ED evaluation of the patient was a CT of the right hand with IV contrast (see Figure 3). It demonstrated diffuse edema and a 9.0-mm area of low attenuation with some rim enhancement. The differential for these findings includes an abscess or a foreign body; the latter was deemed unlikely in light of the patient’s physical exam. In consideration of his elevated WBC count, the high number of WBCs in his urine, the fever, and the CT results, the patient was diagnosed with an abscess in his right hand that had been seeded, it was surmised, by an occult urosepsis after his fall.

Before the patient’s admission, a hand surgeon was consulted. The surgeon agreed with the diagnosis, and the patient was taken to the operating room (OR). He had been given piperacillin/tazobactam in the ED.

In the OR, the surgeon made a 3.0-cm incision, conducted an exploration, and identified a cavity that contained a small amount of purulence. He determined the lesion to be a resolving abscess. The wound was washed out, and the area was closed with a Penrose drain.

The patient was continued on the piperacillin/tazobactam. His blood culture was positive for gram-positive rods, and a low-grade fever persisted. An infectious disease specialist was consulted, and levofloxacin was added to the patient’s regimen.

After 24 hours of treatment, findings on urinalysis improved: blood, small; protein, trace; nitrites, negative; leukocytes, small; WBCs, 15 to 20/high-power field; and no bacteria. Over the next three days, the patient’s condition continued to improve. His hand drain was removed, and the pain and swelling subsided. He became afebrile, and his WBC count fell to 24,700/mcL. He was discharged to home with prescriptions for cephalexin and levofloxacin. Follow-up for postoperative care was arranged with the hand surgeon.

Discussion
Pyomyositis is defined as abscess formation deep within large striated muscles.¹ Although this condition is uncommon, it is believed that an occult bacteremia can seed an area of damaged muscle (compared with healthy muscle, which ordinarily resists infection), allowing an abscess to form.^1,2

Epidemiology
In a 2002 review involving 676 patients with primary pyomyositis, Bickels et al³ reported the condition in ages ranging from two months to 82 years (mean, 28.1 years). In a majority of cases, only a single muscle was involved; 112 patients (16.6%) were identified with multiple-site involvement. Only seven cases (0.1%) involved the hand.

In 452 cases (66.9%), a bacterial agent was identified. Among these, 350 (77%) had a positive culture for Staphylococcus aureus. Other isolates included Streptococcus pyogenes, Escherichia coli, Salmonella enteritidus, and Mycobacterium tuberculosis.^1,3 It should be noted that community-­acquired methicillin-resistant S aureus (CA-MRSA) is being implicated with increasing frequency in cases of pyomyositis.^4-6

Because pyomyositis is not a reportable disease and has not been studied in large clinical trials, its incidence is uncertain, and proposed risk factors have not all been confirmed² (see Table^2,7).

Pathophysiology
While the etiology of primary pyomyositis is unclear, it is believed to be caused by a combination of bacteremia (chronic or transient) and damaged muscle. In a 1960 study published in the Lancet, Smith and Vickers⁸ performed autopsies on 327 patients who had died of culture-positive septicemia. Only two patients were found to have a muscle abscess. At that time, the investigators concluded that both muscle injury and bacteremia would need to be present in order for an abscess to form. In animal studies, bacteremia (eg, S aureus) does not appear to lead to pyomyositis except in cases of muscle abnormality or trauma (eg, electric shock, pinching injury).^9,10

When a history of trauma can be identified in patients with pyomyositis, the condition typically develops near the affected muscle, and the infection appears within days to weeks.3 In cases in which an antecedent infection is identified and hematogenous spread of the bacteria to the skeletal muscle occurs, this is termed secondary pyomyositis.¹¹

Disease Progression
Pyomyositis generally progresses in three stages, beginning with inflammation and advancing to a focal abscess, then to a septic state.³ The first stage develops between seven and 21 days after the initial incident, is typically subacute, involves mild pain and swelling with a “woody” texture, and is occasionally associated with fevers.²

Diagnosis of pyomyositis is usually made during the second stage, 10 to 21 days after the initial incident; by that time, the pain has increased, and the fever is more pronounced. Third-stage infection usually involves fluctuance and sepsis.²

Although MRI is considered most useful in the diagnosis of pyomyositis, CT and ultrasound allow for percutaneous needle aspiration and drainage.³

Treatment
The correct treatment for pyomyositis depends upon the stage at which the disease is identified. During the first stage (before formation of an abscess), antibiotic treatment alone may be sufficient.¹ Once an abscess has formed, an incision and drainage will be required, in conjunction with or followed by appropriate antibiotic therapy.

When pyomyositis is properly treated during the first or second stage, a full recovery is likely.^2,3 By the third stage, surgical debridement is required. Additionally, osteomyelitis may develop in the adjacent bones, followed by muscle scarring, residual weakness, and functional impairment.^2,3 Reported pyomyositis-associated mortality ranges between less than 1% and 4%.^2,12

The Case Patient

The case presented here was of particular interest for two reasons. First, the patient had a traumatic injury that initially caused him no concern but worsened progressively over 14 days. Although this is not the typical presentation of a traumatic injury, the ED staff could very easily have performed a radiograph, made a diagnosis of traumatic hand injury, and discharged the patient.

Second, men in their 60s do not commonly have urinary tract infections.¹³ The patient was questioned frequently by several providers about sexual behaviors, medical problems, and urinary symptoms. Repeatedly, he denied all of these issues. While a urinalysis may be omitted in the evaluation of an otherwise healthy, asymptomatic patient, its results in this case were a key piece of data.

It should be noted that the patient thought it inappropriate to be asked for urine samples. He repeatedly said, “It’s my hand!”

Conclusion
Even in patients presenting with the most routine complaint, a careful evaluation can reveal unexpected, serious problems. This patient complained of pain in his hand some time after a fall and ultimately was treated for an occult urosepsis and hand abscess—pyomyositis, which rarely occurs in small muscles, such as those of the hand. Either condition, left untreated, could have led to serious morbidity or even mortality.

A 65-year-old man presented to the emergency department (ED) with a two-week history of progressively severe pain in his right hand and difficulty moving his fingers. He reported that approximately two weeks earlier, while shoveling snow, he slipped and fell, landing on his right hand. Initially, he had no problems with his hand. He finished his shoveling and continued his normal daily activities.

Within two to three days he started to experience pain in his right hand, which grew progressively worse.

Because he did not have a primary care provider, the patient had a limited medical history. He reported having a mildly elevated prostate-specific antigen test years earlier. He underwent an appendectomy at age 15. He denied any other medical problems.

The patient was taking no medications and reported no known allergies to medications. He denied the use of tobacco, said he had one or two beers on an average day, and denied IV drug use. He was an artist and was married with one adult child. His family history was unremarkable with the exception of an alcoholic sister who died of cirrhosis at age 70.

During triage, vital signs were essentially normal: blood pressure, 142/74 mm Hg; heart rate, 78 beats/min; and respiratory rate, 20 breaths/min. The patient was afebrile at 37.2°C (98.9°F). Physical examination was remarkable for some edema and warmth of the right hand without any notable erythema. There was no evidence of any wound. Fingers all had good sensation; however, flexion of the index and long fingers elicited a significant increase in pain.

The remainder of the exam was unremarkable. The patient’s head was normocephalic and atraumatic. Pupils were equal, round, and reactive to light. Eyes were anicteric, and no rhinorrhea was evident. The neck was supple without palpable lymphadenopathy. Lungs were clear to auscultation bilaterally. No wheezes, rales, or rhonchi were appreciated. The heart had a regular rate and rhythm; no murmurs, rubs, or gallups were noted. The abdomen was soft and non-tender. The extremities, except as previously stated, were normal, with good pulses, sensation, and strength.

Initially, only radiographs of the right hand were ordered (see Figures 1 and 2). These demonstrated soft tissue swelling on the dorsum of the hand, and an area of hypodensity between the first and second metacarpals. There were no fractures, dislocations, or other bone or joint abnormalities.

After a review of the radiographs, it was clear that the patient’s diagnosis was not a simple answer of hand contusion or fracture; thus, the evaluation was expanded. Vital signs were repeated three hours after triage: blood pressure, 128/74 mm Hg; heart rate, 76 beats/min; and respiration, 20 breaths/min. The patient was now febrile at 37.6°C (99.7°F). Because of his fever and the anomaly on the patient’s hand radiograph, expansion of the evaluation continued.

Laboratory studies included a complete blood count: white blood cells (WBCs), 30,700/mcL (reference range,¹ 4,500 to 11,000/mcL); hemoglobin, 13.3 g/dL (13.8 to 17.2 g/dL for men); hematocrit, 40.0% (41% to 50% for men); platelets, 217,000/mcL (130 to 400 x 10³/mcL). Initial chemistry panel results were normal except for serum glucose, 143 mg/dL (70 to 125 mg/dL).

Liver function test results were normal except for aspartate aminotransferase, 33 U/L (reference range,¹ 10 to 30 U/L) and albumin, 2.5 g/dL (3.5 to 5.0 g/dL). Once WBCs were found to exceed 30,000/mcL, the search for a cause was widened once more.

The continued studies included a chest radiograph with normal results, unremarkable CT of the abdomen and pelvis with IV contrast, blood cultures, and urinalysis. The urinalysis showed: blood, moderate; protein, trace; nitrites, positive; leukocytes, large; WBCs > 50/high-power field (reference range,¹ 5/high-power field or less); and numerous bacteria.

The final study performed in the ED evaluation of the patient was a CT of the right hand with IV contrast (see Figure 3). It demonstrated diffuse edema and a 9.0-mm area of low attenuation with some rim enhancement. The differential for these findings includes an abscess or a foreign body; the latter was deemed unlikely in light of the patient’s physical exam. In consideration of his elevated WBC count, the high number of WBCs in his urine, the fever, and the CT results, the patient was diagnosed with an abscess in his right hand that had been seeded, it was surmised, by an occult urosepsis after his fall.

Before the patient’s admission, a hand surgeon was consulted. The surgeon agreed with the diagnosis, and the patient was taken to the operating room (OR). He had been given piperacillin/tazobactam in the ED.

In the OR, the surgeon made a 3.0-cm incision, conducted an exploration, and identified a cavity that contained a small amount of purulence. He determined the lesion to be a resolving abscess. The wound was washed out, and the area was closed with a Penrose drain.

The patient was continued on the piperacillin/tazobactam. His blood culture was positive for gram-positive rods, and a low-grade fever persisted. An infectious disease specialist was consulted, and levofloxacin was added to the patient’s regimen.

After 24 hours of treatment, findings on urinalysis improved: blood, small; protein, trace; nitrites, negative; leukocytes, small; WBCs, 15 to 20/high-power field; and no bacteria. Over the next three days, the patient’s condition continued to improve. His hand drain was removed, and the pain and swelling subsided. He became afebrile, and his WBC count fell to 24,700/mcL. He was discharged to home with prescriptions for cephalexin and levofloxacin. Follow-up for postoperative care was arranged with the hand surgeon.

Discussion
Pyomyositis is defined as abscess formation deep within large striated muscles.¹ Although this condition is uncommon, it is believed that an occult bacteremia can seed an area of damaged muscle (compared with healthy muscle, which ordinarily resists infection), allowing an abscess to form.^1,2

Epidemiology
In a 2002 review involving 676 patients with primary pyomyositis, Bickels et al³ reported the condition in ages ranging from two months to 82 years (mean, 28.1 years). In a majority of cases, only a single muscle was involved; 112 patients (16.6%) were identified with multiple-site involvement. Only seven cases (0.1%) involved the hand.

In 452 cases (66.9%), a bacterial agent was identified. Among these, 350 (77%) had a positive culture for Staphylococcus aureus. Other isolates included Streptococcus pyogenes, Escherichia coli, Salmonella enteritidus, and Mycobacterium tuberculosis.^1,3 It should be noted that community-­acquired methicillin-resistant S aureus (CA-MRSA) is being implicated with increasing frequency in cases of pyomyositis.^4-6

Because pyomyositis is not a reportable disease and has not been studied in large clinical trials, its incidence is uncertain, and proposed risk factors have not all been confirmed² (see Table^2,7).

Pathophysiology
While the etiology of primary pyomyositis is unclear, it is believed to be caused by a combination of bacteremia (chronic or transient) and damaged muscle. In a 1960 study published in the Lancet, Smith and Vickers⁸ performed autopsies on 327 patients who had died of culture-positive septicemia. Only two patients were found to have a muscle abscess. At that time, the investigators concluded that both muscle injury and bacteremia would need to be present in order for an abscess to form. In animal studies, bacteremia (eg, S aureus) does not appear to lead to pyomyositis except in cases of muscle abnormality or trauma (eg, electric shock, pinching injury).^9,10

When a history of trauma can be identified in patients with pyomyositis, the condition typically develops near the affected muscle, and the infection appears within days to weeks.3 In cases in which an antecedent infection is identified and hematogenous spread of the bacteria to the skeletal muscle occurs, this is termed secondary pyomyositis.¹¹

Disease Progression
Pyomyositis generally progresses in three stages, beginning with inflammation and advancing to a focal abscess, then to a septic state.³ The first stage develops between seven and 21 days after the initial incident, is typically subacute, involves mild pain and swelling with a “woody” texture, and is occasionally associated with fevers.²

Diagnosis of pyomyositis is usually made during the second stage, 10 to 21 days after the initial incident; by that time, the pain has increased, and the fever is more pronounced. Third-stage infection usually involves fluctuance and sepsis.²

Although MRI is considered most useful in the diagnosis of pyomyositis, CT and ultrasound allow for percutaneous needle aspiration and drainage.³

Treatment
The correct treatment for pyomyositis depends upon the stage at which the disease is identified. During the first stage (before formation of an abscess), antibiotic treatment alone may be sufficient.¹ Once an abscess has formed, an incision and drainage will be required, in conjunction with or followed by appropriate antibiotic therapy.

When pyomyositis is properly treated during the first or second stage, a full recovery is likely.^2,3 By the third stage, surgical debridement is required. Additionally, osteomyelitis may develop in the adjacent bones, followed by muscle scarring, residual weakness, and functional impairment.^2,3 Reported pyomyositis-associated mortality ranges between less than 1% and 4%.^2,12

The Case Patient

The case presented here was of particular interest for two reasons. First, the patient had a traumatic injury that initially caused him no concern but worsened progressively over 14 days. Although this is not the typical presentation of a traumatic injury, the ED staff could very easily have performed a radiograph, made a diagnosis of traumatic hand injury, and discharged the patient.

Second, men in their 60s do not commonly have urinary tract infections.¹³ The patient was questioned frequently by several providers about sexual behaviors, medical problems, and urinary symptoms. Repeatedly, he denied all of these issues. While a urinalysis may be omitted in the evaluation of an otherwise healthy, asymptomatic patient, its results in this case were a key piece of data.

It should be noted that the patient thought it inappropriate to be asked for urine samples. He repeatedly said, “It’s my hand!”

Conclusion
Even in patients presenting with the most routine complaint, a careful evaluation can reveal unexpected, serious problems. This patient complained of pain in his hand some time after a fall and ultimately was treated for an occult urosepsis and hand abscess—pyomyositis, which rarely occurs in small muscles, such as those of the hand. Either condition, left untreated, could have led to serious morbidity or even mortality.