Total epidermal necrosis and subepidermal blistering is one of the symptoms of toxic necrotizing epidermolysis bullosa rash, and prevention of drug rash must pay attention to what kind of allergy history the patient has before using the drug, and avoid using drugs with known allergies or similar structures. The medication should be targeted, and less allergenic drugs should be used as much as possible. Early symptoms of drug rash should be noted during treatment, such as the sudden appearance of itching, erythema, fever and other reactions, the suspected drug should be stopped immediately, closely observed and try to identify the allergenic drug. For those who have been diagnosed with drug rash, the allergenic drug should be entered into the medical record and the patient should be told to remember it and tell the doctor not to use it at each visit. The patient with drug rash should eat a diet rich in high quality protein; vitamin-rich food; light and easily digestible food; the following foods are recommended to be eaten in moderation: 1. Milk Milk is rich in high quality protein and also contains calcium, phosphorus, iron, potassium, zinc, sodium and other trace elements to provide nutrients for tissue recovery. 350-500ml per day is appropriate. 2, lemon Lemon is rich in vitamin C, vitamin E, promote the proliferation of wound granulation tissue, less scarring, with beauty, anti-inflammatory effect. Infusion of water to drink 350-500ml per day is appropriate. 3, celery celery has a clear heat detoxification, sedative and calming effect, conducive to the absorption of the intestinal tract, and facilitate the recovery of the body. 180-260 grams per day is appropriate. Patients with total epidermal necrosis and subepidermal maculopathy should not eat spicy and stimulating food; avoid eating greasy food; avoid eating fishy food. The following foods are recommended to eat less or not: 1, chili pepper easy to stimulate the vascular nerves, so that blood flow accelerates, easy to stimulate vascular secretion of histamine, bradykinin and other substances, resulting in fever, is not conducive to the recovery of the trauma, to avoid eating. 2, lard lard contains more oil, easy to nourish bacteria, inducing trauma infection, is not conducive to the recovery of the trauma, to avoid eating. 3.Crab is a fishy food, which has an inhibiting effect on the impact of trauma, so avoid eating it as much as possible.