Cutaneous Mycobacterium haemophilum infection with jarisch-herxheimer reaction: A case report from Taiwan

Mycobacterium haemophilum is a slow-growing and iron-dependent nontuberculous mycobacterium that can cause cutaneous ulcerations or nodular lesions. The diagnosis of cutaneous M. haemophilum infection is currently extremely rare in Taiwan. An 80-year-old Chinese man taking oral prednisolone for months presented with multiple erythematous as well as indurated and painful nodules over his right forearm. The diagnosis of M. haemophilum infection was confirmed through positive acid-fast staining - a technique used in histopathology and species identification - which was performed using molecular methods. Notably, Jarisch-Herxheimer reaction developed promptly during the antimicrobial therapy. Ideal skin culture conditions and specific molecular identification techniques are required for optimal detection of M. haemophilum.