Pyomyositis: clinical features and predisposing conditions.

OBJECTIVE: To describe the manifestations of nontropical pyomyositis and associated comorbid conditions that may predispose to pyomyositis.

METHODS: A retrospective review of 13 patients with pyomyositis seen at our center including one illustrative case report. Reports of tropical and nontropical pyomyositis were found by review of Index Medicus, Medline, and references from published cases and clinical review papers.

RESULTS: All 13 patients had variable presentations including fever, muscle pain, tenderness, and swelling. Eleven patients had comorbid conditions that may have led to their infection, including one with human immunodeficiency virus and 3 with history of trauma. Staphylococcus aureus was found to be a causative organism in 7 patients, 2 patients had multiple organisms isolated, and 2 had no organisms isolated. Eleven patients had successful treatment with intravenous antibiotics and either computerized tomographic scan guided percutaneous or open operative drainage.

CONCLUSION: Onset of pyomyositis is usually insidious, with progression to purulent collections. Comorbid conditions likely predispose patients to pyomyositis and may contribute to delay in diagnosis and treatment. Increased awareness of this disease, especially in an immunosuppressed patient, should lead to earlier diagnosis and treatment with improved outcomes.