Itchy skin at the corners of the mouth is considered to be keratitis, herpes simplex, allergies and so on. 1. Keratitis: Keratitis, also known as rotting corners of the mouth, is divided into infectious keratitis and non-infectious keratitis, considered and microbial infections, trauma, nutritional deficiencies, etc., the main manifestation of the corners of the mouth for the area of the dryness of the tightness, burning sensation, part of the itch will also be accompanied. It is recommended to deal with the cause of the disease, such as malnutrition keratitis can take oral vitamin B complex to relieve symptoms. 2. Herpes simplex: herpes simplex is caused by herpes simplex virus infection, is a contagious disease, if herpes occurs in the corners of the mouth area, it will cause local symptoms, the beginning of pain, itching, burning sensation, and then blisters will appear. Treatment is based on astringency, dryness and prevention of secondary infection. Topical acyclovir ophthalmic ointment can be applied 3 or 4 times/day. 3. Allergy: Itchy skin at the corners of the mouth can also occur if you eat certain allergic foods, such as yam, seafood, lamb, etc., and is usually accompanied by symptoms such as numbness of the tongue. If you find a food allergy, you should mainly stay away from the allergic food as soon as possible, which is the most important way to prevent anaphylaxis. Itchy skin at the corners of the mouth may have other causes (such as contact dermatitis), it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.