Elbow long crusty ringworm may be due to psoriasis, neurodermatitis, chronic eczema and other factors, need to clarify the cause of the symptomatic treatment, the common treatment of tretinoin, dexamethasone and other medications, phototherapy, liquid nitrogen freezing and other physical therapy. 1. Psoriasis: related to immunity, genetics, environment and other factors, can be distributed in all parts of the body, the skin manifests as red papules, covered with white scales, and other changes. It can be treated with glucocorticoid drugs such as mometasone furoate, and physical therapy such as phototherapy can also be used. 2. Neurodermatitis: the cause of the disease is not clear, may be related to scratching and chronic friction, commonly found on the back, elbow and other parts of the performance of the local itching or friction and other stimuli, scratching the formation of mossy lesions, normal skin color, reddish, tawny. Mometasone furoate ointment, tacrolimus ointment and other medications can be used, but also phototherapy, liquid nitrogen freezing and other physical therapy. 3. Chronic eczema: it is caused by a combination of internal and external factors, and can occur in any part of the body, manifesting itself as pimples, scratches and scales on the infiltrated dark red patches of the skin, accompanied by skin thickening, pigmentation and other changes. It can be treated with drugs such as mometasone furoate ointment, tacrolimus ointment, and loratadine. Elbow long hard skin ringworm may also be due to other factors, it is recommended that patients seek timely medical treatment in order to clarify the cause of the targeted treatment, avoid private medication, so as not to delay the condition.