Red pimples on the buttocks

Red rash on the buttocks, consider the following diseases, one, urticaria. Urticaria can show wheals and itching anywhere on the body. Two, papular urticaria. Papular urticaria is mainly caused by insect bites in the environment, or irritants in food, and can show papules, bumps, wheals, etc. on the buttocks. Three, eczema. Eczema can show erythema papules, blisters, nodules, plaques, itching, etc. on the buttocks. Four, tinea cruris. Tinea cruris may present as erythema, pimples, blisters, erosions, scales, itching, etc. on the buttocks. Neurodermatitis. Neurodermatitis may present as erythema, pimples, hypertrophy, itching, etc. on the buttocks.