Itchy nail crevices may be ringworm, eczema, contact dermatitis and other diseases. It is recommended to go to the dermatology department of the hospital in time, and use medication under the guidance of the doctor. 1. Ringworm: it is caused by fungal infection, transmitted through skin contact, some patients are infected by their own feet or other parts of the fungus to the hands. The manifestation is the appearance of dense blisters under the skin of the nail seam, blisters itching easy peeling, positive fungal examination. 2. Eczema: the cause of the disease is not known, is internal and external multi-factorial inflammatory skin disease, may be related to heredity, allergies, infections and so on. It is characterized by erythema, itching and oozing at the nail crevice, usually with symmetrical onset. 3. Contact dermatitis: it is a localized allergic reaction caused by some allergens in contact with the skin of the nail seam, common allergens such as nail polish, detergents and so on. The performance of the skin around the nail erythema, pimples, there is obvious itching. Itchy nails may also be the initial symptoms of onychomycosis. It is recommended that patients with this symptom go to the dermatology department of a regular hospital in a timely manner to get a clear diagnosis and standardized treatment under the guidance of a doctor.