Elbow ringworm may be caused by ringworm, neurodermatitis, psoriasis and other reasons. 1. Ringworm: ringworm is a skin disease caused by ringworm infection, which often occurs in the exposed parts of the body, such as the trunk, arms, etc., manifested as red papules, papules and red scaly patches with clear boundaries on the surface of the skin, accompanied by varying degrees of itching symptoms. 2. Neurodermatitis: the cause of neurodermatitis is still unclear, may be related to neuropsychiatric factors, scratching and chronic friction, etc., occurring in the arms, neck, elbow joints, calves, anus and other parts of the body, manifested as a mossy lesion of the skin surface, there may be a little scales on the top, accompanied by symptoms of intense itching. 3. Psoriasis: Psoriasis is an immune-related hereditary skin disease, occurring in elbow joints, knees, scalp, hands, feet and trunk, manifested as a clear border, scaly red patches on the skin surface. Elbow joint ringworm may also have other causes, it is recommended to go to the hospital in a timely manner to improve the examination, to clarify the cause of the disease, and then give targeted treatment.