Ringworm resulting from swimming with a polyurethane cast

A case of ringworm of the arm is described in a 6-year-old child, after swimming with a polyurethane cast. This report illustrates a potential problem when these casts are inadequately dried and worn for prolonged periods in warm climates. Accurate diagnosis depends on demonstration of fungus in the lesion by smear and culture. Topical antifungal therapy led to rapid resolution.