Skin phototoxic reaction is a kind of skin toxic reaction triggered by skin exposure to chemical substances followed by exposure to ultraviolet radiation, or a similar reaction occurring after systemic application of chemical substances and exposure to ultraviolet radiation. In addition, the skin reaction caused by external photosensitive substances that enter the body through the skin or through the mouth and are distributed to the skin tissue after sun exposure can be further divided into phototoxic dermatitis and photomimetic dermatitis. There are many kinds of external photosensitive substances in life, such as asphalt, coal tar, fuel, etc.; bergamot essential oil, lemon oil, sandalwood oil, etc. in cosmetic fragrances; lemon, orange, orange, grapefruit, spinach, amaranth, cilantro, etc. in plants; bone marrow, dahurian dahurica, bupleurum, salvia, solanum, etc. in traditional Chinese medicine; sulfonamide, tetracycline, ashwagandha, chlorpromazine, salicylates and oral contraceptives in Estrogen, etc. Some of these photosensitive substances can induce phototoxic dermatitis, while others cause photopathogenic dermatitis. In fact, there are many things in nature that contain photosensitive substances, and usually we can’t distinguish them by appearance without deliberately inquiring about them. Now, many women friends like to use fruits and vegetables at home to make homemade masks, or sliced directly outside, or beaten into juice to put on the face, in fact, this practice brings great danger to the skin. In addition to the acidic components of the fruit itself will stimulate the skin, some photosensitive substances will also cause the skin to produce a photosensitive skin reaction. In addition, pay attention to sun protection in summer is also an effective way to protect the skin from photosensitive dermatitis, if not sensitive skin, choose chemical and physical with a broad-spectrum sunscreen is the best choice.