Swimming pool granuloma is caused by: March 2010

Ans. C: Mycobacterium marinum Aquarium granuloma/ Fishtank granuloma/swimming pool granuloma results when water containing an infectious organism, Mycobacterium marinum, enters a break in the skin. A localized infection called a granuloma results after about 3 weeks. The person usually has a history of exposure to swimming pools, salt water aquarium, or ocean fish. The lesions appear as reddish bumps (papules) that slowly grow into purplish nodules. The elbows, fingers, back of the hands, and knees are the most common sites affected. The nodules may break down and leave an open sore, or spread up the limb. A skin biopsy and culture is usually needed to confirm the diagnosis. A PPD tuberculin skin test will usually be positive.