Cutaneous non-tuberculous mycobacterial infections: An update

Abstract

Non-tuberculous mycobacteria (NTM) are increasingly recognized as causes of skin and soft-tissue infections. They include rapid-growing and slow-growing species. Hospital outbreaks related to contaminated water and in association with surgical and cosmetic procedures have been described. Infections are also associated with immunosuppression. NTM infections have a wide spectrum of clinical manifestations, though Mycobacterium marinum and Mycobacterium ulcerans manifest characteristic lesions – swimming pool granuloma and Buruli ulcer, respectively. NTM infection should be suspected when the skin infection (especially those following trauma or invasive procedure or in a patient with immunosuppression) does not respond to antibiotics. NTM are acid fast, but will be negative on cartridge based nucleic acid amplification tests for Mycobacterium tuberculosis. Diagnosis is confirmed by polymerase chain reaction test which is the gold standard. NTM show variable susceptibility to antimicrobials and no clear treatment guidelines are available. Surgical treatment may also be needed in some cases.