Red rashes on the body should be treated according to the cause. Viral infections caused by red rash symptomatic treatment can be; allergic reactions caused by red rash to anti-allergy treatment; sun exposure and other physical factors caused by the skin rash should be promptly cooled to prevent sun exposure. 1. Viral infection: before the rash is often accompanied by fever, should pay attention to whether it is a viral rash, such as rubella, measles and so on. Viral infections have no specific drug treatment, the disease is often self-limiting, usually only need symptomatic treatment. Such as actively controlling fever, preventing over-temperature and so on. 2. Allergic reaction: some animal fur, willow floss, drugs, etc. can cause allergic reaction, resulting in red rash, common diseases such as urticaria, contact dermatitis and so on. At this time should be away from allergens, while avoiding re-exposure to allergens, through the external use of glycerite lotion, glucocorticoid ointment, etc., oral antihistamine medication and other treatments. 3. Physical factors: high-temperature sun-induced rash, such as photosensitive dermatitis, first of all, should avoid direct sunlight, reduce the outing and sunscreen, should also be applied locally glucocorticosteroid ointment, oral antihistamine, and so on. It is recommended that patients with rashes go to the hospital in a timely manner, after the cause of the disease is clear, under the guidance of the physician for standardized treatment.