Pneumococcal pyomyositis: report of 2 cases and review of the literature.

Streptococcus pneumoniae is an uncommon cause of pyomyositis. It is unclear whether the clinical presentation and outcome of pneumococcal pyomyositis differ depending on the host's underlying immune status. We describe 2 patients with pneumococcal pyomyositis, review all published cases, and compare characteristics between apparently healthy hosts and at-risk hosts. A total of 35 cases of pneumococcal pyomyositis were identified, 11 in apparently healthy hosts and 24 in at-risk hosts. Two-thirds of the patients had an antecedent respiratory illness or meningitis. At-risk hosts tended to have a longer interval between the development of symptomatic muscle infection and the diagnosis of pyomyositis and a significantly higher risk of disseminated disease at presentation, as manifested by involvement of multiple noncontiguous muscles or presence of meningitis. Overall, other than 1 death, all patients recovered with antibiotics and surgical drainage, but as might be expected there was a significantly higher rate of complications among at-risk hosts.