Mycobacterium marinum

Background

Mycobacterium Marinum is a bacteria that causes "fish tank Granuloma." Not only has it been known to cause disease in aquarium workers and enthusiasts but can also be associated with swimming. Lesions are typically noted on the hands and fingers if the patient works with aquariums or the knees and elbows in swimmers. Infection is secondary to handling of contaminated water. Skin lesions are composed of superficial nodules. This can infect both immunocompetent and immunocompromised hosts.

Clinical Features

solitary to multiple Red nodules or plaques in exposed areas.

• 

  Fish tank granuloma. From: Ryan, J and Bryant G. "Fish tank granuloma - a frequently misdiagnosed infection of the upper limb." J Accid Emerg Med. 1997 Nov; 14(6): 398–400.

• PMCID: PMC1342984

Diagnosis

Diagnosis is clinical aided by histopathology. Lesions are red nodules/plaques. May progress to abscess or deep-space infections. May also disseminate (rare).

Management

1. Long-term antibiotic therapy is often needed. Antibiotic regimens include monotherapy with doxycycline, clarithromycin, bactrim, or minocycline (1, 2). However, secondary to drug high levels of drug resistance, providers may require dual drug therapy.
2. Warm compresses may also help as the bacterium is heat-sensitive.

References

1. Petrini, B; "Mycobacterium Marinum: ubiquitous Agent of Waterborne Granulomatous Skin Infections." European Journal of Clinical Microbiology and Infectious Diseases. October 2006, Volume 25, Issue 10, pp 609-613
2. Rallis, E; Koumantaki-Mathioudaki, E; "Treatment of Mycobacterium Marinum Cutaneous Infections." Expert Opinion on Pharmacotherapy. Volume 8, Issue 17, 2007