The common causes of a small white patch on the face include vitiligo, lichen planus, mottled albinism and so on. 1. Vitiligo: the cause of this disease is unknown, is considered to be the result of a variety of factors, such as autoimmune diseases, oxidative stress, melanocyte self-destruction, strong mental stimulation, genetic factors, etc., good in the exposed parts of the skin, can lead to the symptoms of the white patches of facial skin. 2. lichen planus: this disease is mainly caused by malassezia overproliferation, infants and young children often occur in the face, manifested in pinhead-sized spots, can be fused into white patches and other symptoms. 3. Mottled albinism: this disease is a kind of congenital leukoplakia without melanocytes, manifested as white patches on the face, individual patients have fundus albinism, macular dysplasia and other symptoms. It is recommended that patients go to the hospital in time to clarify the cause of the disease, timely treatment, to avoid delay.