Fish Tank-Associated Mycobacterium Marinum Infection in an Immunocompromised Host

Area of Science:

• Infectious Diseases
• Dermatology
• Immunology

Background:

• Mycobacterium marinum infections pose diagnostic and therapeutic challenges, particularly in immunocompromised individuals using tumor necrosis factor alpha inhibitors.
• Sporotrichoid presentations of M. marinum can mimic other conditions, delaying diagnosis.

Purpose of the Study:

• To highlight the diagnostic difficulties and treatment complexities of Mycobacterium marinum infection in an immunocompromised patient.
• To emphasize the importance of considering atypical mycobacterial infections in the differential diagnosis for immunocompromised patients presenting with sporotrichoid lesions.

Main Methods:

• Case report of a patient with collagenous colitis on infliximab presenting with ulcerated plaques and nodules.
• Diagnostic confirmation via biopsy and identification of M. marinum.
• Treatment involved multiple antibiotic regimens due to observed resistance.

Main Results:

• Initial treatments were ineffective, necessitating a biopsy for definitive diagnosis.
• M. marinum infection was confirmed, requiring a prolonged and complex antibiotic regimen including rifampicin and ciprofloxacin.
• The patient's condition improved with targeted therapy and multidisciplinary management.

Conclusions:

• Urgent diagnostic biopsies are essential for immunocompromised patients with sporotrichoid lesions.
• Patient education regarding aquatic environment avoidance is critical.
• Treatment for M. marinum is lengthy (up to 12 months) and requires ongoing counseling and multidisciplinary care.
• Further research is needed to optimize treatment protocols, which currently recommend ethambutol and macrolides.