Spring is here, the weather is gradually turning hot, people’s outdoor activities increased, the sun is getting stronger, in our clinical sun dermatitis patients also increased, and the onset of such patients is mainly due to ultraviolet radiation in the sun, or the use of food containing photosensitive substances, drugs or cosmetics and then the sun exposure skin allergic reactions. 1, common photosensitive food: vegetables: spinach, lettuce, Chrysanthemum, celery, parsley, amaranth, nasturtium, cabbage, bok choy, bok choy, oilseed rape, snow lettuce, radish leaves, carrots, bitter greens, mustard, marjoram, safflower, purple clover, ash, acacia, etc.; fruit: mango, pineapple, bergamot, sour orange, lemon, grapefruit, figs, etc.; other: buckwheat, shiitake mushrooms, flat mushrooms, fungus, mud snail, shrimp , crab, mussels, seafood, fennel, etc. 2.Common photosensitive Chinese medicine: dahurica, dahurica dahurica, white fresh skin, cumin, etc. 3.Common photosensitive drugs: antibiotics (such as chlortetracycline, doxycycline, oxytetracycline, norfloxacin, flurofloxacin, ofloxacin, enrofloxacin, lomefloxacin, sparfloxacin, sulfonamides, chloramphenicol, gentamicin, etc.) antifungal drugs (such as ashwagandha, itraconazole, ketoconazole) non-steroidal anti-inflammatory drugs (aspirin, sodium salicylate, ibuprofen, diclofenac, etc.) Thiazide diuretics (furosemide, hydrochlorothiazide, dihydrochlorothiazide, aminopterin, etc.) Retinoids (isotretinoin, avobenzoic acid, vincristine, vincristine ointment, tazarotene, adapalene, etc.) Sulfonylurea hypoglycemic agents (glibenclamide tablets, glipizide, D-860, etc.) Antituberculosis drugs (isoniazid, pyrazinamide, etc.) Sedative-hypnotics (chlorpromazine, promethazine, fenadine, etc.) Antineoplastic drugs (vincristine, etc.) Vincristine, etc.) Calcium channel antagonists (nifedipine) ACEI, amiodarone, quinidine, carbamazepine, topical hydroquinone cream, etc. 4, exogenous photosensitizers: fragrances, preservatives, aniline and aniline derivative dyes in cosmetics and detergents, and essential oil components such as sandalwood and verbena, tar, asphalt, etc. Prevention: Participate in outdoor exercise regularly to enhance the skin’s tolerance to sunlight; avoid outdoor activities or reduce the duration of activities between 10 a.m. and 2 p.m. when sunlight exposure is strongest; avoid sun exposure and pay attention to protection when going out, such as holding an umbrella, wearing a wide-brimmed hat and wearing long-sleeved clothes; if outdoors, it is recommended to routinely apply a sunscreen with an SPF of 15 or higher, and those with severe photosensitivity should use SPF30 or higher. Shades should be applied at least 20 minutes before sun exposure. People with sun allergies should avoid taking foods and fruits that contain photosensitive substances. Check the instructions carefully when taking medications.