Gram-Negative Pyomyositis in an Immunocompetent Patient.

Pyomyositis is an acute or sub-acute primary infection of the striated muscles. It is commonly misdiagnosed in its early stages due to its nonspecific presentation and lower suspicion among physicians when it comes to diagnosis. It has been historically associated with tropical climates but is being seen with increasing incidence in temperate regions. In both tropical and temperate areas, Staphylococcus aureus is the most common causative organism; gram-negative organisms are rare and traditionally only seen in immunocompromised patients. We report a case of Klebsiella pneumoniae pyomyositis in an immunocompetent patient with no risk factors. The awareness of the possibility of gram-negative pyomyositis in immunocompetent patients will broaden initial empiric antibiotic treatment, especially in those patients not responding to traditional empiric treatment.