Abstract: A 53-year-old male presented with nodules on the right upper limb for half a year. Dermatological examination revealed several dark red papules and nodules on the right upper limb, some of which were ruptured with purulent and bloody secretions. The right hand was swollen with normal skin temperature and mild tenderness. Histopathology examination revealed infectious granuloma. Tissue mycobacteria culture revealed Mycobacterium marinum. Mycobacterium marinum qPCR (tissue) was positive. Mycobacterium marinum infection was diagnosed based on clinical manifestations and laboratory tests. Minocycline and clarithromycin were given for two months with poor results. The treatment regimen was adjusted to rifampicin, clarithromycin, doxycycline, and dapsone based on the drug sensitivity results. The papules and nodules on the right upper limb extremity basically disappeared after five months.

Key words: Mycobacterium marinum, infectious granuloma