Aquarium granuloma

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Aquarium granuloma
Synonyms	Fish tank granuloma, Swimming pool granuloma
Pronounce	N/A
Specialty	N/A
Symptoms	Skin lesions, ulcers, nodules
Complications	Secondary infection
Onset	2–4 weeks after exposure
Duration	Weeks to months
Types	N/A
Causes	Mycobacterium marinum
Risks	Handling aquariums, fish tanks, swimming pools
Diagnosis	Biopsy, culture
Differential diagnosis	Sporotrichosis, cutaneous leishmaniasis
Prevention	Protective gloves, avoiding exposure to contaminated water
Treatment	Antibiotics such as clarithromycin, doxycycline, rifampin
Medication	N/A
Prognosis	Good with treatment
Frequency	Rare
Deaths	N/A

Aquarium granuloma, also known as fish tank granuloma, is a rare skin infection caused by the bacterium Mycobacterium marinum. This condition is typically associated with exposure to contaminated water in aquariums, swimming pools, or natural bodies of water.

Etiology

Mycobacterium marinum is a non-tuberculous mycobacterium that is found in both fresh and saltwater environments. It is an opportunistic pathogen that can infect humans through small cuts or abrasions in the skin when they come into contact with contaminated water or fish.

Clinical Presentation

The infection usually presents as a localized skin lesion, often on the hands or arms, which are the most common sites of exposure. The lesion typically appears as a reddish or purplish papule or nodule that may ulcerate. Over time, the lesion can develop into a granuloma, which is a small area of inflammation due to the body's immune response to the infection.

Diagnosis

Diagnosis of aquarium granuloma is based on clinical suspicion, especially in individuals with a history of exposure to aquariums or fish tanks. Confirmation is achieved through microbiological culture of the organism from a biopsy of the lesion. Mycobacterium marinum grows optimally at lower temperatures (around 30°C), which is a key factor in its identification.

Treatment

Treatment of aquarium granuloma involves the use of antibiotics. Commonly used antibiotics include clarithromycin, doxycycline, and rifampin. The choice of antibiotic and duration of treatment depend on the severity of the infection and the patient's response to therapy. In some cases, surgical excision of the lesion may be necessary.

Prevention

Preventive measures include wearing protective gloves when handling aquariums or fish tanks, especially if there are any cuts or abrasions on the skin. Proper maintenance and cleaning of aquariums can also reduce the risk of infection.

See also

• Mycobacterium marinum
• Granuloma
• Skin infection
• Non-tuberculous mycobacteria