[Two severe cases of disseminated cutaneous nontuberculous mycobacteriosis due to Mycobacterium haemophilum].

Mycobacterium haemophilum is a rare pathogen belonging to the group of slowly growing nontuberculous mycobacteria (NTM) that can cause infections, especially in immunocompromised patients. Detection by culturing is difficult because M. haemophilum only grows under special cultivation conditions. Therefore, it is believed that the pathogen is too rarely identified as a cause of disease overall. In addition to patients with severe immunodeficiency, e.g. due to acquired immunodeficiency syndrome (AIDS), chemotherapy or immunosuppression after transplantation, patients with underlying rheumatic diseases are increasingly described in the literature, who are at risk due to the immunosuppressive treatment regimen. Clinically, ulcerative skin alterations, lymphadenopathy and arthropathy are in the foreground. In immunosuppressed patients with unclear skin lesions, infections due to M. haemophilum should be considered and specific microbiological diagnostics should be initiated.