Measles is an acute respiratory infection caused by measles virus, which is highly contagious and mostly seen in children. Clinical features include fever with runny nose, cough, ocular conjunctivitis and special measles mucosal spots and widespread skin maculopapular rash all over the body. The typical symptoms of the prodromal phase of measles include symptoms of upper respiratory tract infection, such as fever, cough, runny nose and tearing eyes, photophobia, etc., and can be accompanied by varying degrees of general malaise. The fever is mainly low day and high night, and can increase day by day, even up to 39℃ or 40℃ or more. For infants and children, febrile convulsions may occur, while older children may complain of headache, dizziness or fatigue, drowsiness, etc. The cough may also increase day by day, mostly dry, and may be accompanied by hoarseness and other manifestations of laryngitis. Some children may also experience gastrointestinal discomfort, such as poor appetite, nausea, vomiting, and diarrhea. In addition, the characteristic sign is that 2-3 days after the onset of fever, the buccal mucosa of the oral cavity, i.e., the buccal mucosa of the first molar, may appear as a mucosal spot of measles, which is a characteristic sign of the prodromal phase of measles and has early diagnostic significance. After 3-5 days of fever and 1-2 days after the emergence of the klebsiella, a rash may appear all over the child’s body. The sequence of the rash generally has a characteristic, that is, from behind the ears, hairline and then gradually spread to the neck, head and face, and then from top to bottom to the chest, trunk and limbs, and finally to the heart of the hands and feet, generally this process will last 2-3 days, while the rash out gradually into the recovery period of measles.