Ringworm is a fungal infection of the skin that occurs in the groin, perineum, around the anus and buttocks, and is a form of tinea corporis that occurs in specific areas. It can occur unilaterally or bilaterally and has a tendency to recur. It begins with an erythematous, flaky surface in the groin, with the lower edge more distinct and the upper edge less so. The central part of the erythema is self-healing and is often bordered by papules, papules and blisters, forming a well-defined circumscribed or semi-circumscribed erythema. It tends to be one-sided at first, and then occurs bilaterally, with its margins expanding outward, spreading along the thighs downward or along the groin upward and even up to the lower abdomen, and also spreading to the perineum, or expanding backward to the vicinity of the anus and the buttocks. As the affected area is poorly ventilated, moist and sweaty, and often prone to friction, the skin lesions are prone to erosion or eczema-like changes, and obvious itching occurs. If the above symptoms occur, it is recommended to go to the hospital in time for early and regular treatment.