[Pyomyositis: an infectious complication in systemic lupus erythematous].

Pyomyositis is a primary pyogenic muscular infection. It has been originally described in the tropics. Presenting signs and symptoms are not specific. It is frequently misdiagnosed in the early stages. We report the case of a 47-year-old woman with systemic lupus erythematosus treated with corticosteroids who presented a thigh pyomyositis evidenced by echography and MRI. Outcome was uneventful after antibiotics and surgical drainage. Pyomyositis is increasingly described among immunocompromised people, including lupus patients treated with corticosteroids.