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Swimming pool granuloma
Aquarium granuloma; Fish tank granuloma
A swimming pool granuloma is a long-term (chronic) skin infection. It is caused by the bacteria Mycobacterium marinum .
Causes
A swimming pool granuloma occurs when water containing Mycobacterium marinum bacteria enters a break in the skin. Signs of a skin infection appear about 2 to 3 weeks later.
Risks include exposure to swimming pools, salt water aquariums, or ocean fish.
Symptoms
The main symptom is a reddish bump ( papule ) that slowly grows into a purplish and painful nodule .
Papule
A papule is a solid or cystic raised spot on the skin that is less than 1 centimeter (cm) wide. It is a type of skin lesion.
Nodule
Skin nodules are solid or cystic raised bumps in the skin that are wider than 1 centimeter (cm), but less than 2 cm.
The elbows, fingers, and back of the hands are the most common body parts affected. The knees and legs are less commonly affected.
The nodules may break down and leave an open sore. Sometimes, they spread up the limb. Most often they stay a simple skin sore.
Exams and Tests
The health care provider will perform a physical examination and ask about your symptoms.
Tests to diagnose swimming pool granuloma include:
-
Skin test
to check for tuberculosis infection, which may look similar
Skin test
The PPD skin test is a method used to diagnose silent (latent) tuberculosis (TB) infection. PPD stands for purified protein derivative.
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Skin biopsy
and culture
Skin biopsy
A skin lesion biopsy is when a small amount of skin is removed so it can be examined. The skin is tested to look for skin conditions or diseases. A...
Read Article Now Book Mark Article - X-ray or other imaging tests for infection that has spread to the joint or bone
Treatment
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.
Outlook (Prognosis)
Swimming pool granulomas can usually be cured with antibiotics. But, you may have scarring.
Possible Complications
Tendon, joint, or bone infections sometimes occur. The disease may be harder to treat in patients whose immune system is not working well.
When to Contact a Medical Professional
Call your health care provider if you develop reddish bumps on your skin that do not clear with home treatment.
Prevention
Wash hands and arms thoroughly after cleaning aquariums. Or, wear rubber gloves when cleaning.
References
Vega-Lopez F. Mycobacterium marinum infection. In: Magill AJ, Hill DR, Solomon T, Ryan ET. Hunter's Tropical Medicine and Emerging Infectious Disease . 9th ed. Philadelphia, PA: Elsevier; 2013:chap 59.
Review Date: 2/3/2015
Reviewed By: Amit M. Shelat, DO, FACP, Attending Neurologist and Assistant Professor of Clinical Neurology, SUNY Stony Brook, School of Medicine, Stony Brook, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.
