LAUSR

DEAR EDITOR, A 46-year-old woman presented with a 1-month history of plaques and nodules with ulceration on the upper arms after an injection lipolytic procedure 2 months previously (a). She initially received levofloxacin, cefprozil and ebastine at another clinic, but failed to respond. Histological examination revealed an abscess and granulomas without caseous necrosis in the middle and lower dermis (b). Ziehl–Neelsen staining showed acid-fast bacilli. Mycobacterium immunogenum was cultured and confirmed by genetic sequencing. The patient was commenced on oral clarithromycin and rifampin and had improved 2 months later (c). Mycobacterium immunogenum is a rare, nontuberculous mycobacterium resistant to standard disinfectants. Infections are usually associated with penetrating trauma and present as inflammatory papules, plaques, abscesses, nodules and ulcerations.