Dissemination of localized Mycobacterium malmoense infection in an immunocompromised patient.

A 75-year-old woman with a history of immunosuppressive treatment for rheumatoid arthritis and non-Hodgkin lymphoma, was referred to our reference centre for treatment of tenosynovitis caused by Mycobacterium malmoense, which had disseminated due to immunosuppressive therapy. This rare diagnosis was made after years of treatment for supposed rheumatoid arthritis. The patient presented with relapsing tenosynovitis with wounds on her right middle finger and wounds on her left lower leg, despite 3 months of adequate therapy (rifampicin+ethambutol+clarithromycin). Therapy was intensified with amikacin, clofazimine, moxifloxacin, and interferon-gamma due to the lack of response. Amputation of the right middle finger was necessary due to advanced disease. Treatment was further complicated by a paradoxical reaction, requiring prednisone treatment, which ultimately led to cure.