Fever with rash in a 3-year-old child may be caused by measles, hand-foot-mouth disease and other diseases. Treatment is symptomatic and should be based on the specific disease. 1. Measles (1) The rash of measles appears 3~4 days after the fever. There is no specific treatment, mainly symptomatic treatment, strengthen care and prevention of complications. (2) Children with measles should rest in bed, pay attention to indoor warmth and air circulation, avoid bright light stimulation, pay attention to skin, eyes, nose, mouth clean, drink more water, give easy to digest and nutritious food. (3) If the body temperature is greater than 38.5 degrees Celsius, antipyretics such as acetaminophen and ibuprofen can be used as appropriate, but rapid fever reduction should be avoided, especially during the rash period. Large amount of vitamin A supplement can be given to patients with measles to minimize the occurrence of complications. 2. Hand, foot and mouth disease (1) Children with hand, foot and mouth disease may have fever, scattered rash and herpes on hands, feet, mouth and buttocks. There is no specific antiviral drug for treatment, and the child should be isolated and treated symptomatically. (2) Children with fever (greater than 38.5 degrees Celsius), oral acetaminophen, ibuprofen and other drugs to reduce temperature or antipyretic patches and other physical cooling as prescribed by the doctor. Secondly, take good care of the skin and mouth, keep clean. Do isolation, appropriate rest, light diet. 3-year-old children with fever accompanied by a rash, should go to the local hospital to clarify the diagnosis, the professional doctor symptomatic treatment, follow the doctor’s instructions for medication.