What is the definition of Swimming Pool Granuloma?

A swimming pool granuloma is a long-term (chronic) skin infection. It is caused by the bacteria Mycobacterium marinum (M marinum).

What are the alternative names for Swimming Pool Granuloma?

Aquarium granuloma; Fish tank granuloma; Mycobacterium marinum infection

What are the causes for Swimming Pool Granuloma?

M marinum bacteria usually live in brackish water, unchlorinated swimming pools, and aquarium tanks. The bacteria can enter the body through a break in the skin, such as a cut, when you come into contact with water that contains this bacteria.

Signs of a skin infection appear about 2 to several weeks later.

Risks include exposure to swimming pools, aquariums, or fish or amphibians that are infected with the bacteria.

What are the symptoms for Swimming Pool Granuloma?

The main symptom is a reddish bump (papule) that slowly grows into a purplish and painful nodule.

The elbows, fingers, and back of the hands are the most commonly affected body parts. The knees and legs are less commonly affected.

The nodules may break down and leave an open sore. Sometimes, they spread up the limb.

Since the bacteria cannot survive at the temperature of the internal organs, they usually stay in the skin, causing the nodules.

What are the current treatments for Swimming Pool Granuloma?

Antibiotics are used to treat this infection. They are chosen based on the results of the culture and skin biopsy.

You may need several months of treatment with more than one antibiotic. Surgery may also be needed to remove dead tissue. This helps the wound heal.

What is the outlook (prognosis) for Swimming Pool Granuloma?

Swimming pool granulomas can usually be cured with antibiotics. But, you may have scarring.

What are the possible complications for Swimming Pool Granuloma?

Tendon, joint, or bone infections sometimes occur. The disease may be harder to treat in people whose immune system is not working well.

When should I contact a medical professional for Swimming Pool Granuloma?

Call your provider if you develop reddish bumps on your skin that do not clear with home treatment.

How do I prevent Swimming Pool Granuloma?

Wash hands and arms thoroughly after cleaning aquariums. Or, wear rubber gloves when cleaning.


Brown-Elliott BA, Wallace RJ. Infections caused by Mycobacterium bovis and nontuberculous mycobacteria other than Mycobacterium avium complex. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases, Updated Edition. 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 254.

Patterson JW. Bacterial and rickettsial infections. In: Patterson JW, ed. Weedon's Skin Pathology. 4th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2016:chap 23.

There is no recent research available for this condition. Please check back because thousands of new papers are published every week and we strive to find and display the most recent relevant research as soon as it is available.

There are no recent clinical trials available for this condition. Please check back because new trials are being conducted frequently.