What causes redness above the lips and below the nose, and what should be done about it?
Redness that appears above the upper lip and below the nose is usually caused by frequent friction or skin irritation, dry environment, contact dermatitis, seborrheic dermatitis, or perioral dermatitis. It is recommended to seek medical attention promptly, identify the underlying cause, and then improve the condition under a doctor's guidance through general care, medication, and other treatments. Detailed analysis is as follows:

1. Frequent friction and skin irritation: Repeated touching with hands or wiping with rough tissues can damage the local skin barrier, leading to redness and discomfort. Immediately stop such friction, switch to using a soft cotton pad to gently blot and absorb moisture, avoid touching the affected area with hands, and minimize external irritants.
2. Dry environment: In dry seasons such as autumn and winter, or due to insufficient water intake, the local skin may lose moisture quickly, causing the stratum corneum to become dry and fragile, resulting in redness. Use a humidifier indoors to maintain humidity between 40%–60%, drink more than 1,500 mL of water daily, apply fragrance-free moisturizing creams to lock in moisture, and avoid licking the area.
3. Contact dermatitis: Allergic reactions caused by lipsticks or skincare products containing irritating ingredients may lead to localized redness accompanied by itching and burning. Discontinue use of suspected products immediately, cleanse the area with lukewarm water, and follow medical advice to use medications such as loratadine tablets, desonide cream, or hydrocortisone butyrate cream. Choose mild, simple-formula skincare products.
4. Seborrheic dermatitis: This area contains abundant sebaceous glands; excessive oil secretion can trigger inflammation, causing redness with greasy scales. Patients should use medications such as ketoconazole shampoo, pimecrolimus cream, or tacrolimus ointment as directed by a physician. Reduce dietary intake of high-fat and high-sugar foods, and cleanse the face once daily with a gentle facial cleanser.
5. Perioral dermatitis: Often triggered by long-term use of fluoride-containing toothpaste or topical corticosteroid creams, this condition presents with clearly defined red patches accompanied by small papules. Discontinue use of fluoride toothpaste and any suspect topical steroids, and follow medical advice to use metronidazole gel, azelaic acid cream, or doxycycline tablets. Avoid consuming spicy or irritating foods that may aggravate the affected area.
Maintain a light diet in daily life and consume more fresh fruits and vegetables to supplement vitamins. Practice sun protection when going outdoors by wearing wide-brimmed hats or applying gentle sunscreen. Maintain regular sleep patterns and avoid staying up late to strengthen skin resistance, promoting recovery of the affected skin through scientific skincare practices.