Fingernail edge old hard skin may be dry climate and other physiological factors, may also be ringworm, hand eczema and other diseases caused. 1. Physiological factors: if the climate is too dry, it may lead to skin dehydration, thus causing the old hard skin on the edge of the fingernail. 2. Ringworm: the etiology is mainly related to the infection of dermatophytes such as Trichophyton rubrum and Trichophyton interdigitalis. The patient’s hands can appear hyperkeratosis, blisters and other symptoms, and some patients may appear the edge of the fingernail old hard skin. 3. Hand eczema: the specific cause is not clear, may be related to hormone level changes, genetic and other factors, the patient fingers, palms and other parts of the skin will appear thickening, peeling, cracking and other symptoms. There are more reasons for the old hard skin on the edge of the fingernail, after excluding physiological factors, it is recommended to go to a regular hospital to clarify the cause of the disease.