Prolonged Mycobacterium Marinum Infection of the Hand, Wrist, and Forearm: A Case Report

Introduction/Background Mycobacterium marinum is a nontuberculous mycobacterium that can cause rare chronic skin and soft tissue infections in humans. Exposure is most common in individuals who work closely with marine animals or in marine environments, including aquarium caretakers and fishermen, and is typically acquired through a break in the skin or a fish bite. Diagnosis can be challenging due to its indolent nature and requires a high index of suspicion, including the elicitation of a water exposure history. As a result, it is often associated with delayed diagnoses, leading to chronic infections and related complications, such as arthritis, tenosynovitis, osteomyelitis, and bursitis. Case Presentation We present a case of a 59-year-old male who had previously worked as a fisherman and developed a chronic right upper extremity rash that was initially misdiagnosed as psoriasis, only later to be diagnosed as M. marinum infection 10 years after its initial onset. Laboratory confirmation was made through histopathology, tissue culture, and PCR. Conclusion This report highlights the epidemiology, clinical presentation, diagnostic difficulties, and complex management of Mycobacterium marinum infection.