Mycobacterium chelonae infection in an immunocompromised patient presenting as multiple papulonodules on the leg.

Mycobacterium chelonae is a rapidly growing nontuberculous mycobacteria that is a rare cause of cutaneous infections in both immunocompromised and immunocompetent patients. The clinical presentation is heterogeneous and non-specific, and therefore, despite an increasing incidence of these infections, patients are often misdiagnosed. Here we present the case of an immunocompromised 73-year-old female patient that developed tender, erythematous, violaceous to brownish papules and nodules on both the anterior and posterior aspects of her left lower leg. A histopathological examination revealed acid-fast bacilli, and a tissue culture identified M. chelonae. Disease resolution was achieved with long-term targeted antibiotic therapy based on susceptibility testing.