Nocardiosis-an uncommon infection in patients with myasthenia gravis: report of three cases and review of literature.

Nocardiosis is a rare infection in patients with myasthenia gravis (MG). We identified three cases of MG admitted with nocardiosis in our unit. We performed systematic literature search of previous publications and identified 18 patients. This paper presents three patients and reviews the clinical characteristics of 21 patients. The first case was a 69-year-old woman with thymomatous MG who presented with pustules and left lower limb pain. Evaluation showed osteomyelitis of the pubic ramus and ileopsoas abscess. The second case was a 54-year-old man who presented in myasthenic crisis due to pulmonary nocardiosis. The third case was a 48-year-old man with thymomatous MG who presented with lung abscess. All of them recovered completely after treatment with co-trimoxazole. Analysis of the 21 patients identified four risk factors for nocardiosis in MG: elderly men; thymoma; immunosuppressant medication, mainly steroid therapy; and pre-existing lung disease. Lungs was the most common site of infection. Suppurative disease was common manifestation regardless of organ involved. Clinical course is not unfavourable.