Bacterial pyomyositis

Case report: A case of piriformis pyomyositis and pyogenic sacroiliitis due to non-typhoidal Salmonella bacteremia in an immunocompetent healthy adult

Non-typhoidal Salmonella (NTS) rarely causes bacteremia and subsequent focal infections as an extraintestinal complication, even in immunocompetent adults. A 25-year-old man was hospitalized for several days with difficulty moving due to fever, acute buttock pain, and shivering. He had no recent or current respiratory symptoms and no clear gastrointestinal symptoms. Physical examination revealed mild redness around the left buttock and difficulty raising the left lower extremity due to pain, in addition to which blood tests showed high levels of inflammatory markers. His clinical course and laboratory findings suggested sepsis, and magnetic resonance imaging revealed a high-intensity area in the left piriformis muscle on diffusion-weighted imaging; therefore, acute piriformis pyomyositis was strongly suggested. Cephazolin was started upon hospitalization; however, blood and stool cultures proved positive for NTS, and the antibiotics were changed to ceftriaxone. Follow-up MRI showed a signal in the left piriformis muscle and newly developed left pyogenic sacroiliitis. On the 25th hospital day, a colonoscopy was performed to identify the portal of entry for bacteremia, which revealed a longitudinal ulcer in the sigmoid colon in the healing process. His buttock pain gradually improved, and the antibiotics were switched to oral levofloxacin, which enabled him to continue treatment in an outpatient setting. Finally, the patient completed seven weeks of antimicrobial therapy and returned to daily life without leaving any residual disability. Invasive NTS infection due to bacteremia is rare among immunocompetent adults. Piriformis pyomyositis and subsequent pyogenic sacroiliitis should be added to the differential diagnosis of acute febrile buttock pain. In the case of NTS bacteremia, the entry site must be identified for source control. Additionally, the background of the host, especially in such an immunocompetent case, needs to be clarified; therefore, the patient should be closely examined.

Unprovoked piriformis myositis presenting in a pregnant patient

A patient in her mid-30s presented to hospital at 25 weeks' gestation with acute onset of leg pain.Routine investigations were performed to rule out the common causes of leg and back pain in pregnancy, which were grossly normal. Piriformis pyomyositis was diagnosed on MRI and a collection was drained. Following an initial response to antibiotic therapy, the patient delivered by elective caesarean section, but the pain returned on postnatal day 2 and muscle inflammation was diagnosed again, requiring a repeat course of antibiotics.This case highlights a rare cause of leg pain in a pregnant patient, and the additional complexities of managing cases in the obstetric population.

Subscapularis pyomyositis: a rare presentation of shoulder pain

We present a rare case of a subscapularis pyomyositis in a 38-year-old woman and examine the diagnostic and surgical challenges posed. History and examination features were similar to that of septic shoulder arthritis without overlying features of warmth or erythema. Serological markers revealed a C-reactive protein of 221 mg/L and white cell count of 11.1×10⁹/L. A dry shoulder aspirate was obtained. Contrast-enhanced MRI demonstrated a peripheral rim-enhancing lesion within the subscapularis muscle belly with lack of central enhancement. These features are consistently seen with an infective aetiology. A deltopectoral approach to surgical drainage was utilised and subsequent fluid cultures grew Panton-Valentine Leukocidin positive Staphylococcus aureus species. This rare bacterium is associated with an increased risk of osteomyelitis and despite making a full recovery, the patient was advised to reattend if any future shoulder pain was encountered.

Necrotising pyomyositis complicating intramuscular antipsychotic administration

A 26-year-old woman with paranoid schizophrenia was admitted to the medical intensive care unit with septic shock requiring intubation and mechanical ventilation. The source of septic shock was not identified despite obtaining CT of the chest/abdomen/pelvis, bronchoalveolar lavage and microbiological results for tracheal secretions, blood, urine and cervix. An indium-111 tagged white cell count scan was subsequently performed, revealing increased right anterior deltoid uptake. Owing to serial increases (up to 1310 U/L) in serum creatine kinase and a history of local intramuscular paliperidone injections for management of schizophrenia, surgical exploration was performed and identified necrotising skeletal muscle inflammation and extensive fat necrosis with an organising abscess, consistent with pyomyositis. A gram stain of purulent fluid revealed gram-positive cocci, but no organisms grew in culture. The patient recovered after 10 days of daptomycin and 7 weeks of wound care. Paliperidone injections were discontinued and oral risperidone was initiated.

Pyomyositis

Pyomyositis is the primary infection of the skeletal muscle. It is common in the tropics, but is increasingly being reported worldwide. It can affect immunocompromised and immunocompetent individuals. Staphylococcus aureus is the most common causative organism. Muscle histology and its culture remain the gold standard for diagnosis. However, among noninvasive methods, MR imaging is highly sensitive and can image large areas of the body and detect subclinical involvement. Early diagnosis, institution of appropriate antibiotic therapy, and drainage of pus lead to favorable outcome.

Streptococcus anginosus (Streptococcus milleri Group) Pyomyositis in a 50-Year-Old Man with Acquired Immunodeficiency Syndrome: Case Report and Review of Literature

We describe the first reported case of bacterial pyomyositis of the right thigh caused by Streptococcus anginosus (S. milleri group) in an HIV-infected patient. The clinical presentation was complicated by multiple ring-enhancing lesions detected on magnetic resonance imaging of the brain. Evaluation for central nervous system toxoplasmosis,syphilis, and cryptococcal infection was negative. Aggressive antibiotic therapy directed against S. anginosus and surgical debridement were limb salvaging. Clinicians should considerS. anginosus as a causative pathogen in HIV-associated pyomyositis, particularly in complex presentations. Prompt surgical drainage may minimize complications due to S. anginosus, a pathogen associated with significant sequelae due to its invasive nature.

Primary erector spinae pyomyositis causing an epidural abscess: case report and literature review

BACKGROUND CONTEXT

Primary pyomyositis (PM) is a rare bacterial infection of skeletal muscle usually restricted to tropical zones. Typically caused by Staphylococcus aureus, primary staphylococcal PM associated with an epidural abscess has not been reported before.

PURPOSE

We present the first case of staphylococcal PM associated with an epidural abscess.

STUDY DESIGN

Case report.

PATIENT SAMPLE

A 56-year-old woman.

OUTCOME MEASURES

Clinical follow-up at 9 months.

METHODS

This 56-year-old woman presented with a sudden onset of left lumbar back pain and sciatica without prior illness. She was pyrexial on admission, with elevated inflammatory markers but with no obvious systemic source of sepsis.

RESULTS

Spinal magnetic resonance imaging and subsequent surgery revealed an erector spinae abscess causing an epidural abscess via the left L4/5 intervertebral foramen. Both back pain and sciatica were immediately improved postoperatively. Culture revealed S aureus as the sole organism sensitive to flucloxacillin. Intravenous therapy was converted to oral after 12 days once the erythrocyte sedimentation rate had normalized and she was asymptomatic. She remains asymptomatic and without clinical signs at the 9-month follow-up.

CONCLUSION

Spinal infection must always be considered when back pain and sciatica are associated with clinical signs of sepsis. We present the first case of staphylococcal PM associated with an epidural abscess.

Piomiositis: una revisión retrospectiva en un hospital terciario del norte de España

OBJECTIVE

To describe the clinical, radiological and microbiological features of a series of patients diagnosed with pyomyositis in a tertiary care university-affiliated center over a 12-year period.

PATIENTS AND METHODS

The medical records of all patients diagnosed with pyomyositis between January 1992 and December 2003 were reviewed. The charts were retrieved from the hospital database. Data were extracted according to a standardized protocol and included clinical, radiological, laboratory and microbiological parameters.

RESULTS

A total of 54 patients (mean age, 50 years, 61% men) had pyomyositis. The most frequent predisposing factors were diabetes mellitus (22%) and traumatic injury (20%), followed by neoplasms (9%). Primary pyomyositis was diagnosed in 25 patients (55%), and a contiguous source of infection was detected in the remainder, with skin infection being the most frequent (40%). The most common presentation was isolated inflammatory signs with or without other symptoms (94%). Isolated fever was documented in only one patient. Ultrasonography was the most common diagnostic procedure performed (32%), followed by CT scanning (18%). Forty-five patients underwent a drainage procedure combined with antibiotic therapy. Pyomyositis was monomicrobial in 20 cases, and polymicrobial in 12. The most frequent pathogen was Staphylococcus aureus followed by coagulase-negative staphylococci (6 cases). Sepsis developed in 4 patients, and recurrence was observed in 8 (15%). Mortality was 10% (5 patients).

CONCLUSIONS

Pyomyositis is a relatively uncommon infection in temperate climates, and is often considered late in the diagnostic workup. Physicians should bear this disease in mind to avoid diagnostic delays and initiate prompt therapy, in order to improve the prognosis of these patients.

Tropical and Temperate Pyomyositis

Pyomyositis is a primary infection of skeletal muscle not arising from contiguous infection, presumably hematogenous in origin, and often, but not invariably, associated with abscess formation. Classically, pyomyositis is an infection of the tropics, occurring in previously active and healthy young men. Pyomyositis in temperate countries is often regarded as an infection that occurs in hosts who are immunocompromised or otherwise debilitated. However,this distinction may be somewhat artificial, as tropical pyomyositis may be partly related to underlying infection with HIV or parasites, and temperate pyomyositis has been reported in healthy and athletic persons. This article discusses the pathogenesis, clinical presentation, diagnosis, and management of pyomyositis in the tropical and temperate settings.