Hand, foot and mouth disease is an infectious disease caused by enteroviruses. There are more than 20 kinds of enteroviruses (types) that cause hand, foot and mouth disease, among which coxsackievirus type A16 and enterovirus type 71 are the most common. Most children under the age of 5 years old show painful mouth, anorexia, low fever, small herpes or ulcers on the hands, feet, mouth and other parts of the body, and most children heal spontaneously in about a week. Individual children with severe disease develop rapidly, leading to death. There is a lack of effective treatment drugs mainly symptomatic treatment. Second, the etiology There are a variety of enteroviruses can cause hand, foot and mouth disease. The most common are coxsackievirus type A16 and enterovirus 71. The route of infection includes gastrointestinal, respiratory and contact transmission. Clinical manifestations Hand, foot and mouth disease mainly occurs in children under 5 years old, incubation period: mostly 2-10 days, an average of 3-5 days. 1, common case performance Acute onset, fever, mouth pain, anorexia, oral mucosa appear scattered herpes or ulcers, located in the tongue, cheek mucosa and hard palate, etc., can also spread to the soft palate, gums, tonsils and pharynx. The hands, feet, buttocks, arms, and legs appear as macules, which later turn into herpes, which may be surrounded by an inflammatory redness and less fluid in the blisters. The hands and feet are more frequent, and the back of the palms are present. The number of rashes can be as few as a few or as many as several dozen. The rash does not leave traces after fading, and there is no hyperpigmentation. In some cases, the rash is only a rash or herpetic pharyngitis. Most cases heal within a week and have a good prognosis. In some cases, the rash is atypical, such as a single site or only a maculopapular rash. In a few cases (especially those younger than 3 years old), the disease progresses rapidly, with meningitis, encephalitis (brainstem encephalitis is the most dangerous), encephalomyelitis, pulmonary edema and circulatory disorders appearing in 1-5 days after the onset of the disease, and in very few cases, the disease is critical and can lead to death. (1) The neurological manifestations can be seen as poor mental health, drowsiness, easily startled, headache, vomiting, delirium or even coma; limb tremors, myoclonus, nystagmus, ataxia, oculomotor disorders; weakness or acute flaccid paralysis; convulsions. On examination, meningeal irritation signs, diminished or absent tendon reflexes, and positive Bartholomew’s sign were seen. The combination of central nervous system symptoms is more common in children under 2 years of age. (2) Respiratory system manifestations include shallow breathing, dyspnea or rhythm changes, lip cyanosis, coughing, coughing white, pink or bloody foamy sputum; wet rales or sputum sounds can be heard in the lungs. (3) Circulatory system manifestations can be seen when myocarditis is complicated by pale gray face, skin pattern, cold extremities, cyanosis of fingers (toes); cold sweating; prolonged capillary refill time. Heart rate increases or decreases, pulse rate is shallow or weak or even disappears; blood pressure increases or decreases.