Clinical characteristics and predictors of mortality in 67 patients with primary pyomyositis: a study from North India.

Primary pyomyositis is infection of the skeletal muscles in the absence of adjacent skin, soft tissue, and bone infection. This study was undertaken to look at the spectrum of clinical presentations, therapeutic interventions, and their outcomes and also to evaluate the association of various risk factors with mortality. This was a retrospective study in which the patients admitted with the diagnosis of primary pyomyositis from January 2000 to June 2007 were included. Their demographic details, clinical and laboratory data, Sequential Organ Failure Assessment (SOFA) score at presentation, treatment instituted, complications encountered, and hospital outcome were recorded. Sixty-seven patients (42 males and 25 females) with a diagnosis of primary pyomyositis were included. Median age at the time of presentation was 37 years (interquartile range = 25-50 years). Common presenting symptoms were myalgias [50 (74.62%)] and fever [49 (73.13%)]. Twenty-six patients had underlying predisposing medical conditions. The commonest muscle group involved was iliopsoas muscles in 31 (46.26%) patients. Methicillin-sensitive Staphylococcus aureus was the commonest organism isolated from the pus. Twenty-eight patients developed sepsis and seven died. On univariate analysis, there was a statistically significant association between higher SOFA score, lower Glasgow coma scale, higher pulse rate, lower blood pressure, raised blood urea, raised serum creatinine, higher serum glutamic pyruvate transaminase, raised total bilirubin at presentation, and development of sepsis during hospital stay with mortality. In our study, the patients were seen almost a decade later than those seen in other studies from the region. Evidence of organ dysfunction at presentation and sepsis was associated with increased mortality.