Redness and swelling around the mouth, accompanied by itching, is commonly seen in clinical practice in perioral dermatitis, which is an allergic skin disease, mainly caused by problems in the mouth, special stimuli, and improper skin care, as follows: 1. Problems in the mouth: there are problems in the mouth, such as the presence of gums or periodontal problems. 2. Special stimuli: considered as whether there is some special stimuli, such as the habit of drinking water with lips to suck wrap the bottle, as well as in the lips coated with special substances, resulting in irritation. 2, improper skin care: the problem of improper skin care, the skin has a dry, especially the skin of the lips peeling, may be due to the application of inappropriate ingredients of ointment, so that the skin of the lips produce excessive stimulation, and cause an allergic reaction. For these cases, in the treatment of perioral dermatitis, it is necessary to strengthen local skin moisturization and hydration, which can be done by cold compresses of pure water and collagen hyaluronic acid mask to promote skin hydration and moisturization and increase the repair of the skin barrier, and also assist in oral multivitamins, such as oral vitamin B or vitamin C. Oral calcium can also be taken to help inhibit vascular permeability and reduce edema and allergic reactions. In case of severe edema with intense itching, oral compound glycopyrrolate tablets and olopatadine hydrochloride tablets can be taken, and topical medications can be mixed with topical tacrolimus ointment and urea vitamin E cream, and also topical zinc oxide ointment can be chosen. Therefore, for patients with redness and swelling around the mouth with itching, it is recommended to go to the dermatology department of a regular hospital and be treated under the guidance of a professional dermatologist.