In the face of fierce ultraviolet rays in the hot summer, sun protection has become a hot topic. Especially allergy patients, skin barrier damage, reduced defense function, ultraviolet rays are more likely to cause photosensitivity and aging, sunscreen is particularly important. Need to do the following: 1, choose the time to go out in the summer every day from 9 a.m. to 3 p.m. UV rays are strong, this time to minimize going out. Must go out, as far as possible back to the sun, try to walk in the shade, and do a good job of sun protection. 2, physical shielding Wear a wide-brimmed or masked sun hat, UV umbrellas, sunglasses, can cover the bare arms, shoulders of the white shawl, driving the best choice of people with UV protection of the sun film affixed to the windows and other parts of the car. 3, sunscreen Allergies in the acute stage as far as possible physical cover, after the transition into remission can choose physical sunscreen, the advantage is good security, not easy to allergy. Before buying, it is best to try it on the inside of your wrist or behind your ear to make sure you are not allergic before applying it on your face. Every about 3 hours need to reapply, because the sunscreen agent has its own effective time limit, in addition to the influence of sweat it is not possible to stay on the skin for too long, so no matter how thick the coating, after a period of time the efficacy will be weakened, especially in the outdoor sports time longer, it must be hand hard. 4, post-sunburn repair If the skin is slightly red after the sun, you can immediately use cold water wet compress, with a calming effect; you can also put cold water into the refrigerator to cool down before applying. Use moisturizers to promote skin barrier repair. If the skin feels hot and painful relief is not obvious or even aggravating trend, timely to the hospital dermatology consultation for further treatment. 5, avoid photosensitive foods or drugs Photosensitive substances are absorbed into the skin, if irradiated at this time strong light, will react with sunlight, and then appear exposed part of the skin red rash, and accompanied by obvious itching, burning or stinging sensation and other symptoms. Foods such as mud snail, ashwagandha, purple clouds, snowdrops, parsnip, lettuce, fennel, amaranth, capers, celery, turnip leaves, spinach, buckwheat, parsley, rape, mustard greens, fresh mushrooms, fungus, and so on. Fruits such as portobello, mango, prunes, limes, Persian oranges, figs, etc. Drugs such as: tetracycline antibiotics doxycycline, minocycline, etc.; sulfonamide sulfadiazine, etc.; quinolone norfloxacin, ofloxacin, ciprofloxacin, sparfloxacin, etc.; antifungals such as ashwagandha; oral hypoglycemic drug D-860; sedative drugs in the isoprinosine, chlorpromazine; diuretics, such as tachyzoin, hydrochlorothiazide, etc.; non-steroidal anti-inflammatory drugs such as ibuprofen, ketoprofen, naproxen, naproxen, and other anti-drugs. ibuprofen, ketoprofen, naproxen, celecoxib, and so on. Photoreceptors in cosmetics can be found in preservatives, dyes, fragrances, and fluorescent substances in lipsticks, and in sunscreen cosmetics, such as aminobenzoic acid and its lipid compounds.