Rash is not a technical term, it should refer to a red rash, for example, red patches, papules, macules, patches, etc. can be considered a rash. Red rashes can be contagious or non-contagious, and whether they are contagious or not cannot be generalized, but depends on the specific disease. A. Infectious red rash 1. Rubella: Patients usually have symptoms of low fever or a generalized rash, especially behind the ear or swollen lymph nodes can occur. It can be treated with medications such as Banlangen granules and Ribavirin. In addition, patients need to take rest and supplement with vitamin-rich, easily digestible food. 2. Scarlet fever: Patients can have sudden fever symptoms in addition to a red rash. The treatment cycle for scarlet fever is usually 7-10 days, and patients with milder conditions can be cured and receive systematic standardized treatment to shorten the course of the disease and help them recover. The prognosis is good. 3. Infectious erythema: Patients with milder conditions can generally be treated without treatment and will heal on their own. More serious patients can be treated with drugs according to medical advice, patients with anemia can be treated with blood transfusions, and those with impaired immune function can be injected with immunoglobulin; 4, measles: patients can have a red rash on the face with symptoms of cough and fever, which can be treated with drugs, such as antipyretics, cough suppressants, etc. Most patients can recover in 2-3 weeks. Second, non-contagious rash 1, eczema: eczema occurs in the face, ears, hands, feet and other exposed parts, need to pay attention to stay away from the surrounding possible allergens, avoid excessive scratching and cleaning the affected area, the use of drug therapy, such as antihistamines, antibiotics, hormones, etc.; 2, dermatitis: dermatitis patients with typical symptoms of rash, blisters, itching, etc., can use glucocorticoid ointment, furnace glycolic lotion, boric acid solution, etc. The majority of patients can be cured, but some stubborn people can be recurrent; 3, urticaria: most patients will appear on the surface of the skin red windbag-like papules, can disappear on their own, but can not be completely cured. As the cause of the rash is very many, so the rash appears, to the hospital’s dermatology department in a timely manner, after the doctor’s examination to determine the cause of the medication, patients should not blindly use drugs, so as not to aggravate the disease, for the future treatment and recovery brought about by adverse effects. In daily life, do a good job of daily care, avoid excessive scratching to avoid infection of other parts of the body, do not eat spicy and stimulating food, which is not conducive to the recovery of the skin.