Carbamazepine and phenytoin sodium are commonly used in the treatment of facial spasms, but drug reactions occasionally occur during the course of drug administration. Among them, carbamazepine is more common than phenytoin sodium, and more serious. The vast majority of its adverse reactions are due to drug rash caused by allergic reactions. Both drugs cause adverse reactions have a certain latency period, generally ranging from a few days to several days. The clinical manifestations are from mild erythema and papules to severe exfoliative dermatitis, erythema herpetiformis, toxic epidermolysis bullosa. Systemic symptoms are more pronounced, with drug fever of 38 degrees or more. Sometimes the low-grade fever is easily ignored and the heart rate is increased. Lymph node enlargement, or limited or angioedema, is often seen. Erythema and papules appear first on the skin of the chest, back and feet as scattered red spots and papules with mild itching, which soon spread to the head, face, mouth, limbs and anus, etc. They may also continue to develop into severe exfoliative dermatitis, which can be life-threatening if not diagnosed and treated in time. Other adverse effects of carbamazepine and phenytoin sodium include dizziness, liver damage, and decreased white blood cells. They are related to individual differences and should be observed during the treatment process for timely detection and treatment. The diagnosis is generally not difficult based on clinical symptoms and medical history. A small number of patients may have an incubation period, which is easily neglected and should be given high priority. In such cases, allergy-causing drugs should be discontinued first, while avoiding the application of drugs with similar chemical composition that can cause cross-allergic reactions, as well as cautiously using or avoiding the use of other drugs with strong antigenicity. Most of the cases have a good prognosis if they are diagnosed early and treated actively. Once the diagnosis is confirmed, anti-allergic drugs are given in a timely manner while the drug is discontinued. In severe cases, high doses of intravenous adrenocorticosteroids, antibiotics, vitamins and aseptic isolation should be given, and topical medications should be applied appropriately. Commonly used drugs include: dexamethasone, methylprednisolone, ketamine, cyproheptadine, glyburide lotion, etc. If the liver function is severely damaged, apply liver-protective drugs in time and avoid using drugs that damage the liver. In case of declining white blood cells, stop the drugs for observation in mild cases, and apply drugs that promote white blood cell production in severe cases.