The sudden white piece on the face may be vitiligo, seborrheic dermatitis or anemic nevus, anaplastic nevus, as follows: 1, vitiligo: mainly due to genetic, immune, melanocyte self-destruction or neurological factors, etc. Patients can apply tacrolimus ointment or pimecrolimus ointment externally, orally take white erosion pill, repellent white babu period tablets, white spirit tablets, etc., and also myeloablative injection; 2, seborrheic dermatitis: visible light white The patient can use topical zinc borate oxide softener. Patients can use zinc oxide borate ointment and take levocetirizine hydrochloride capsule orally for treatment; 3. Anemic nevus and non-pigmented nevus: these rashes do not need treatment.