Ringworm on the sides of the elbows and buttocks may be due to chronic lichen simplex, tinea corporis, psoriasis and other factors. 1. chronic lichen simplex: also known as neurodermatitis, the cause is not yet clear, may be related to scratching, chronic friction, mental factors, with intense itching, long-term stimulation of the formation of lichen simplex. 2. ringworm: elbows and buttocks on both sides of the ringworm does not exclude the possibility of ringworm, which occurs in the superficial parts of the skin of the fungal infection, may occur in any part of the body, will be infected because of direct contact or indirect contact with pollutants, so the patient will elbows and buttocks on both sides of the ringworm symptoms. 3. Psoriasis: also known as “psoriasis”, which is caused by a variety of factors interacting with the chronic scaly skin disease, usually on the basis of genetic susceptibility, and thus affected by environmental factors to appear onset of the disease, may involve the whole body of the skin, scalp and joints, so the patient will be elbows and buttocks on both sides of the phenomenon of ringworm. If the patient’s symptoms are serious, or the symptoms continue to see no improvement, should promptly go to the hospital for treatment.