Compared with the general population, photosensitivity reactions are more likely to occur in people with delicate skin, children, the elderly, women, and patients with human immunodeficiency diseases, lupus erythematosus, and impaired immune function. Therefore, these people must take appropriate protective measures when using photosensitive drugs, especially in summer when people are relatively less clothed, and should read the drug instructions carefully when taking the drugs to understand the drug ingredients and possible adverse reactions in order to avoid damage from photosensitivity reactions. Common preventive measures include: 1. Patients with a history of photosensitivity reactions should use photosensitive drugs with caution. During the use of photosensitizing drugs and within 5 days after discontinuation, avoid contact with sunlight or ultraviolet light. If photosensitivity reactions or skin damage occur, immediately stop using drugs with photosensitivity effects, change to other drugs for the treatment of the primary disease, and go to the dermatology department for consultation, do not use drugs indiscriminately on your own initiative to avoid delaying the disease. 2, if the drug after sun exposure and allergy, need to be in the skin when the initial tingling sensation or erythema, immediately avoid the sun, with cold water wet compress red swollen fever parts. Patients who have had photosensitivity reactions should not receive sunlight or ultraviolet radiation when the symptoms have not disappeared or within 5 days after the symptoms have disappeared, in order to avoid the occurrence of photosensitivity reactions again. 3, susceptible people should pay special attention to skin protection during the use of photosensitive drugs, and patients who need to take medication for a long time should inform the doctor truthfully in order to choose non-photosensitive drugs, if there is no alternative drug or photosensitivity reactions are mild, you can also consider continuing to take medication, but you must avoid sun exposure as much as possible, especially from 10 am to 3 pm is the strongest time of daylight, pay attention to wear long clothes when going out Wear long clothes, long pants, a sun hat or umbrella, and sunscreen on exposed areas before going out. Once a rash appears on exposed areas and there is a recent history of drug use, the disease should be highly suspected and the suspected drug should be stopped immediately; avoid local scratching and go to the dermatologist in time. It is best to carry the instructions of the recently taken medication with you when you visit the clinic to facilitate the doctor’s treatment.