Chicken skin, which was not there before and then suddenly appeared, is considered to be related to the stimulation of external factors and pathological factors such as keratosis pilaris. 1. External factors: Chicken skin, which was not there before and then suddenly appeared, may be caused by external factors, such as cold stimulation or emotional changes, and may appear transiently, generally do not need special treatment. 2. Pathological factors: perifollicular keratosis, which may cause the patient’s skin to appear follicular keratosis pilaris, may be a normal physiological phenomenon, and genetically related. In addition, vitamin A deficiency may also cause perifollicular keratosis pilaris. Keratosis pilaris does not affect the health of the body and usually does not require special treatment. If the symptoms are serious, you can go to the dermatology department of the hospital. Medications such as salicylic acid ointment, urea ointment, retinoic acid ointment or oral acephate, which have the effect of softening or dissolving the keratin, can be given under the supervision of a doctor and can help relieve the symptoms.