Mycobacterium marinum infection: a case report

Area of Science:

• Infectious Diseases
• Dermatology
• Microbiology

Background:

• Mycobacterium marinum causes uncommon skin infections in humans, typically presenting as chronic, indolent lesions.
• Diagnosis often involves a delay due to the need for a high index of suspicion.

Observation:

• A case of a chronic, undiagnosed Mycobacterium marinum infection on the dominant hand of an immunocompetent patient is presented.
• The injury persisted for at least five years, with multiple consultations yielding no definitive diagnosis.
• Histopathology revealed tuberculoid granulomas, but acid-fast bacilli were not detected.

Findings:

• Culture and polymerase chain reaction-restriction enzyme analysis (PRA)-hsp65 confirmed Mycobacterium marinum infection.
• Treatment with clarithromycin (1 g/day) for three months resulted in a positive outcome.

Implications:

• Clinicians must maintain a high index of suspicion for Mycobacterium marinum infections, especially with chronic skin lesions.
• Awareness of this contact zoonosis is vital for early diagnosis and management.
• Preventive measures should be advised for at-risk professionals, such as aquarium handlers.