The common causes of periungual keratosis include corns, periungual warts, and so on, and the causes of different diseases are different. 1. corns: this disease is due to long-term mechanical stimulation (such as pressure and friction) caused by excessive proliferation of the cuticle, often occurring in the nail periphery, manifested in a clear border of yellowish or dark yellow conical cuticle embolus, smooth surface, and the skin surface flat or slightly elevated, the local pressure will be painful and other symptoms. 2. perinatal warts: this disease is caused by human papilloma virus infection, often occurring in the skin of the hand, can appear in the fingers around the lesions of soybean size or larger gray-brown, brown, or skin-colored pimples, the surface is rough, the texture of the hard, can be papillary hyperplasia symptoms. It is recommended that patients according to their own situation, timely to the regular hospital dermatology consultation, follow the doctor’s instructions to clarify the diagnosis, reasonable treatment, usually to reduce skin friction.