Swimming pool granuloma

Last Updated: 2023-07-07

Author(s): Anzengruber F., Navarini A.

ICD11: 1B21.2Y

Fish tank granuloma, aquarium granuloma, swimming pool granuloma, fish tank granuloma, fish fancier's finger, surfers' nodules, fish-handlers' nodules.

Atypical mycobacteriosis. Infectious disease caused by Mycobacterium marinum. Contact with mostly tropical ornamental fish is indicative for the diagnosis.

  • Inoculation of the pathogens through small skin lesions when cleaning an aquarium, or when swimming, diving etc. 
  • Pathogen: Mycobacterium marinum (syn. Mycobacterium balnei).

  • Erythematous bluish, ulcerative nodule or granuloma. Spread from the skin to deeper tissues incl. joints and bones is possible.

  • Clinic.
  • Biopsy with dermatopathological and microbiological work-up.

  • Acres, back of the hand, elbow, back of the foot and knee.

Tubercle with central necrosis.

  • Spontaneous healing after 12-24 months.
  • Prophylaxis
  • Wearing gloves when cleaning the aquarium.


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