Total epidermal necrosis and subepidermal maculopapular is one of the symptomatic manifestations of toxic necrolytic epidermolysis bullosa type of drug rash, most drugs have the potential to cause drug rash, including herbal medicines, but those with strong antigenicity cause the most. Most of them are sulfonamides, salicylates, antipyretic and analgesic drugs such as pau tazone and aminopyrine, phenolphthalein, penicillin, tetracycline, barbiturates, and phenytoin sodium. In addition, the risk of drug rashes is greater in patients with congenital allergic diseases of the organism and in patients with diseases of vital organs. Toxic necrolytic epidermolysis bullosa (TEN) is the most severe form of drug rash and is usually seen first in the emergency room. Sulfonamides, salicylates, antipyretic and analgesic drugs such as pau tazone and aminopyralid, phenolphthalein, penicillin, tetracycline, barbiturates, and phenytoin sodium. 2.Clinical manifestations The onset of the disease is rapid, accompanied by high fever, irritability, drowsiness, convulsions, coma and other obvious symptoms of systemic poisoning. Skin manifestations are epidermal necrosis and subepidermal blister formation. At the beginning of a large bright red patches, followed by purple-brown, 1 ~ 2 days on the spot appeared blisters and expansion, subsynthesis tens of centimeters in size, showing most of the parallel stripes crepe. The blisters are very easy to rupture and appear large erosion, similar to the second degree of scalding. nilolsky’s sign (x), at the same time, the mouth, eyes, nose, upper respiratory tract, pubic area, esophagus at the mucous membrane, can be widely involved. The mucous membrane is detached and a large vesicular surface appears. The pain is extreme. The body temperature often stays at 40℃ for 2~3 weeks. Heart, kidney, liver and brain are also often involved. The prognosis is serious, with a mortality rate of 25%~50%. Mostly due to secondary infection, liver and kidney dysfunction, water and electrolyte disorders and death.