Solar dermatitis is a delayed-onset photomorphic skin disease induced by sunlight. Some people believe that it is mainly caused by medium-wave ultraviolet light, while others believe that it is mainly caused by long-wave ultraviolet light. Clinical manifestations of polymorphic rash may include erythema, papules, blisters, vesicles, scales, and mossy changes, often dominated by a certain rash. Solar dermatitis, commonly known as sun spots, generally appear within hours after exposure to the sun in the exposed areas of the skin redness, swelling, blisters or blisters. Burning, itching or tingling at the site of the lesions. In mild cases, the rash can gradually subside in 1-2 days, with flaking or different degrees of hyperpigmentation; in severe cases, it can be accompanied by flu-like symptoms, such as fever, fatigue, general malaise, etc., and it can be recovered in about a week or so. In the hot summer, we must do a good job of sunscreen. Sunscreen should be applied about half an hour before going out, and it is best to reapply it again when you go out so that your skin can effectively absorb it and achieve the effect of sun protection. If you are just on the way to and from work to contact the sunshine of the office workers, choose SPF15 or so of the sunscreen is appropriate; if you want to swim, outdoor activities, then you should choose SPF30 or even higher waterproof sunscreen, but need to use a special cleanser to clean when you unload your makeup; for the light sensitive people, it is best to use SPF12 ~ 20 sunscreen. Choose a sunscreen that suits your skin type, oily skin should choose a lotion watery sunscreen with strong penetration; dry skin should choose a cream sunscreen with more oil; sensitive skin is best able to choose the right sunscreen under the guidance of a cosmetic dermatologist. In addition, avoid eating light-sensitive food, light-sensitive food such as parsley, celery, white radish, leek, etc., will aggravate the skin spots, should try to avoid eating. And shark fins, eel, winter melon, cherries, tomatoes, bananas, watermelon and sinews are excellent sunscreen food, eat more can be ingested from the moisturizing sunscreen ingredients.