What causes dark, dry, and itchy skin at the corners of the mouth, and how should it be treated?
Dec 01, 2025
Source: Cainiu Health
Dr. Liu Wenmin
Introduction
In general, darkening, dryness, and itching at both corners of the mouth may be caused by frequent lip licking and irritation, dry environments leading to moisture loss, angular cheilitis, contact dermatitis, or post-inflammatory hyperpigmentation. It is recommended to seek medical attention promptly, identify the underlying cause, and follow a doctor's guidance for improvement through general measures, medication, or other treatments. In daily life, avoid spicy or excessively hot foods to reduce irritation to the skin around the mouth.
Darkening, dryness, and itching on both sides of the mouth are usually caused by frequent lip-licking, environmental dryness leading to moisture loss, angular cheilitis, contact dermatitis, or post-inflammatory pigmentation. It is recommended to seek timely medical attention, identify the underlying cause, and follow a doctor's guidance for improvement through general care, medication, or other treatments. Specific causes are analyzed as follows:
1. Frequent lip-licking irritation: Enzymes in saliva irritate the skin around the corners of the mouth, accelerating water evaporation and causing dryness. Repeated irritation leads to thickened, darkened skin. Immediately stop the habit of lip-licking. Apply fragrance-free petroleum jelly lip balm whenever dryness is felt. After eating, gently wipe the corners of the mouth with warm water and reapply the lip balm.
2. Environmental dryness and moisture loss: In autumn and winter, low air humidity causes the thin, delicate skin at the corners of the mouth to lose moisture easily. Dry, peeling skin may become pigmented due to friction. Use a humidifier indoors to maintain humidity between 40% and 60%, drink at least 1,500 mL of water daily, and wear a mask outdoors to reduce wind irritation.
3. Angular cheilitis: Inflammation caused by bacterial or fungal infection or vitamin B2 deficiency, characterized by redness, dryness, and itching at the corners of the mouth, often leaving dark marks after healing. Follow your doctor’s instructions to use medications such as erythromycin ointment, vitamin B2 tablets, or mupirocin ointment. Increase intake of vitamin B2-rich foods like eggs and spinach.
4. Contact dermatitis: Allergic reactions triggered by lipsticks or toothpastes containing irritating ingredients, resulting in redness, swelling, and itching at the corners of the mouth, with pigmentation remaining after symptoms subside. Discontinue use of suspected products immediately. Follow medical advice to use medications such as loratadine tablets, desonide cream, or hydrocortisone butyrate cream. Choose mild, fluoride-free toothpaste.
5. Post-inflammatory pigmentation: After previous inflammation or injury at the corner of the mouth heals, increased activity of melanocytes causes localized darkening, often accompanied by dryness and discomfort. Under medical guidance, use skin-lightening agents such as hydroquinone cream, tretinoin cream, or azelaic acid cream to fade pigmentation. Avoid rubbing the corners of the mouth and maintain proper moisturization and sun protection.
In daily life, avoid spicy or hot foods to reduce irritation to the skin around the mouth. Thoroughly cleanse the lips after makeup to prevent residue buildup. Maintain regular sleep patterns and avoid staying up late. With balanced nutrition and proper skincare, gradually improve the condition of dark, dry, and itchy corners of the mouth.
