White skin inside the mouth may be physiological factors, but also may be the manifestation of certain diseases, such as oral leukoplakia, thrush, pemphigus, lichen planus, etc., should be timely consultation to identify the cause. 1. Physiological factors: usually do not like to drink water, every time until really thirsty time to drink some, which will lead to extreme dehydration, thus appearing in the mouth of white skin symptoms, so usually must pay attention to timely replenishment of water. 2. Pathological factors: (1) oral leukoplakia: the center of oral leukoplakia necrosis can appear white mucous membrane skin, surrounded by slight congestion and redness, and pain is obvious. (2) Thrush: white membranous material will appear in the oral mucosa, resembling white mucous membrane skin, is a kind of weak immunity patients, especially infants and young children are prone to diseases. (3) Pemphigus: Blister-like damage usually occurs in the mucous membranes of the mouth or other parts of the mouth, and when the blisters dry up, white skin can be found on the mucous membranes. (4) lichen planus: lichen planus is a chronic inflammatory disease involving the skin, hair follicles, nails, mucous membranes, this disease usually occurs in middle-aged people, the cause of the disease is still unclear, considering that may be related to psychiatric factors, but also may be the cause of endocrine factors, the disease can lead to the patient to appear in the mouth to fall off the skin of the white flocculent symptoms.