Fishy story: paradoxical reaction associated with Mycobacterium marinum

Paradoxical reactions occur when an infection has acute worsening in response to antibiotic therapy. Here, we describe a patient with chronic cutaneous ulcerative lymphangitis that acutely worsened following initiation of antibiotic therapy. The infection was caused by Mycobacterium marinum, a species which has not previously been associated with paradoxical reaction in immunocompetent persons. In this case report, we describe our patient's diagnosis and management, review the management of Mycobacterium marinum infection, and discuss paradoxical reactions in mycobacterial disease.