Generally scarlet fever cannot be detected by checking the blood picture. Scarlet fever can be diagnosed on the basis of clinical features, throat swab smear or secretion culture. Scarlet fever is an acute respiratory infectious disease caused by streptococcal infection, which mostly occurs in children. Scarlet fever can be diagnosed by its clinical features, which include fever, sore throat, and a bright red rash all over the body. Scarlet fever can also be diagnosed by culture of a throat swab or pus collection, and the presence of group A streptococcus will confirm the diagnosis of scarlet fever. Scarlet fever is highly contagious. When the patient is found to have scarlet fever after examination, he/she should be isolated at home. Tableware and household utensils used by the patient should be sterilized every day, windows should be opened at least three times a day for ventilation, and patients in the acute stage should rest in bed. When patients develop scarlet fever, they should go to specialized hospitals for consultation in a timely manner to avoid affecting their condition and infecting more people.