What should I do if my face turns red in hot weather, similar to an allergic reaction?

Under normal circumstances, facial redness caused by hot weather—similar to an allergic reaction—may be due to facial blood vessel dilation, skin dehydration and impaired barrier function, contact dermatitis, rosacea, or steroid-dependent dermatitis. It is recommended to seek timely medical attention, identify the underlying cause, and then improve symptoms under a doctor's guidance through general care, medication, and other treatments. Specific causes are analyzed as follows:

1. Facial vascular dilation: In hot weather, facial capillaries dilate due to heat, increasing blood flow and causing facial redness. When going outdoors, take sun protection measures such as wearing wide-brimmed hats or using umbrellas to avoid direct sunlight; carry a small fan for cooling and minimize prolonged exposure to high temperatures; use lukewarm water to wash your face to avoid thermal irritation from extreme temperature changes.

2. Dehydrated skin with weakened barrier: High temperatures accelerate moisture loss in the skin, impairing its barrier function and increasing sensitivity to external stimuli, leading to redness. Use a gentle, hydrating cleanser daily, and immediately after cleansing, apply moisturizing products such as hyaluronic acid lotion, ceramide cream, or medical-grade petroleum jelly. Regularly use hydrating face masks to replenish skin moisture.

3. Contact dermatitis: Exposure to allergens such as sunscreen or skincare products can trigger inflammation, which is worsened by heat, resulting in facial redness accompanied by itching. Immediately discontinue suspected products and, under medical guidance, use medications such as loratadine tablets, calamine lotion, or desonide cream. Choose medical skincare products with simple, non-irritating ingredients.

4. Rosacea: Caused by genetic factors or abnormal neurovascular regulation, high temperatures may trigger episodic facial flushing, often accompanied by papules and pustules. Follow a doctor’s instructions to use topical medications such as metronidazole gel, azelaic acid cream, or oral doxycycline hydrochloride tablets. Avoid spicy foods, emotional fluctuations, and exposure to high temperatures.

5. Steroid-dependent dermatitis: Long-term use of skincare products or ointments containing corticosteroids can lead to skin dependency, making the face prone to redness and swelling in hot conditions. Under medical supervision, switch to non-steroidal treatments such as tacrolimus ointment, pimecrolimus cream, or vitamin E cream. Gradually discontinue steroid-containing products and maintain consistent sun protection and moisturization.

In daily life, maintain a light diet and consume more hydrating fruits and vegetables such as watermelon and pear, while avoiding alcohol and spicy foods. Keep a regular sleep schedule and avoid staying up late to strengthen the skin’s resistance. With proper skincare and standardized treatment, symptoms of facial redness in hot weather can be reduced, promoting overall facial skin health.