Finger joint skin keratosis may be friction can be physiological factors, but also may be ringworm, callus and other diseases lead to. 1. Physiological factors: if you have been engaged in hand labor for a long time, you may make your hands often bend or suffer friction, which may trigger local joint skin keratosis. 2. Tinea cruris: tinea cruris patients are mostly manifested as hyperkeratotic lesions on palms or fingers, which are flaky, dry and other symptoms, with the growth of time, there may be thickening of keratinization, and its etiology is mostly related to dermatophyte infections. 3. callus: the cause of the formation of callus and long-term extrusion, friction and other mechanical stimuli, callus is mainly manifested as skin roughness, thickening and the appearance of hard bulges, mostly in the hands and feet. Causes of keratosclerosis of the skin of the finger joints are more reasons, after excluding physiological factors, it is recommended that the patient consult a doctor for examination to clarify the cause of the disease.