Pyomyositis

Abstract

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.

Rapid bedside diagnosis of pyomyositis with ultrasound-guided needle aspiration

“…The pathophysiology and presentation of the disease can make it difficult to diagnose. Other conditions such as DVT, cellulitis, myositis or muscular hematoma may have similar presentations adding to the diagnostic difficulty [2] . The presentation of pyomyositis occurs in a three stage process.…”

“…In the United States, HIV-negative patients who develop pyomyositis frequently have a predisposing medical condition. In temperate climates it is associated with underlying conditions such as diabetes, malignancy, HIV infection and chronic liver disease [2,3] . Blunt trauma as well as muscle overuse injuries is among other etiologies of pyomyositis, often involving hematomas that become infected [4] .…”

“…Primary pyomyositis most commonly affects the quadriceps, gluteal and iliopsoas muscles and occurs in three consecutive stages: diffuse muscle infection, abscess formation, and sepsis [6] . Physical exams often overlap with less emergent pathology, including cellulitis, hematoma or superficial abscess and a discrete abscess may not always be palpable [2] . Traditionally, MRI is the preferred diagnostic tool.…”

Point-of-care ultrasound differentiates pyomyositis from cellulitis

“…Pyomyositis is primarily an infection of tropical climates, affecting young and healthy patients [1]. The infection is typically bacterial in etiology.…”

“…The infection is typically bacterial in etiology. Staphylococcus aureus accounts for up to 90% of cases with group A streptococci, gramnegative bacilli, and Mycobacterium tuberculosis also as causative organisms [1,2]. Viral, fungal, and parasitic cases have been reported.…”