Emergency rash is a common acute rash infection in infants and young children. The disease often starts suddenly, with a sudden onset of high fever that does not go away. Parents are often at a loss as to what to do; after a few days, the fever easily subsides, but a rose-colored papular rash appears all over the body, will it leave traces? Parents are again scared and worried. The disease usually starts rapidly with sudden onset of high fever without antecedent symptoms, with a temperature of 39-40°C or more, persistent or fluctuating, occasionally with febrile convulsions, may be accompanied by mild cough or diarrhea, often with loss of appetite, generally no significant mental changes, and mild systemic symptoms. Usually the high fever lasts for 3-5 days and then the fever suddenly decreases, falling to normal within 24 hours. A rose-colored macular rash appears when the fever subsides or a few hours to 1~2 days after the fever subsides, and fades when pressed. The rash mostly occurs on the neck and trunk first, and then gradually spreads to the extremities and face, while the rash is mostly absent on the cheeks, elbows, below the knees and palmoplantar areas. In addition to fever and rash, there may be non-specific manifestations such as runny nose, light cough or nausea, vomiting, and increased stool frequency, etc. Some children may have febrile convulsions when their body temperature rises suddenly, which requires attention. The child may have swollen lymph nodes in the neck and behind the occipital area. The entire course of the disease is 8-10 days. The disease is spontaneous and requires only symptomatic treatment in mild cases. In the case of high fever, give plenty of water and easily digestible food and antipyretic drugs to prevent febrile convulsions. Convulsions require prompt medical attention. For children with special health conditions, such as immune compromised children or those with severe disease, antiviral treatment should be provided in a timely manner. There is no effective way to prevent this disease. Take care to isolate the affected child until 3-5 days after the rash appears. Children in close contact with kindergarten should be observed for 7-10 days, and try not to take infants and children to crowded public places.