Yimaitong compiled and organized, please do not reprint without authorization. Scarlet fever is a common acute respiratory infectious disease in school-aged children and adolescents, caused by group A beta-hemolytic streptococcus. The main clinical manifestations are fever, angina and rash. Because group A streptococcus (GAS) infection can develop purulent and non-purulent complications, acute infection requires treatment to prevent these complications. Learn more about the evaluation and treatment of scarlet fever! 
01Etiology and EpidemiologyThe causative agent of scarlet fever is GAS. The bacteria itself and the toxins and proteases produced by the bacteria are involved in the pathogenic process, which can cause a series of purulent, toxic and allergic lesions. The disease can occur all year round, especially in winter and spring. The population is generally susceptible, but the disease is more common in children, especially children and adolescents aged 5 to 15 years. The difference in incidence between children and adults may be due to the presence or lack of immunity. GAS can exist in the nasal mucosa, adenoids and tonsils. Patients and carriers are the main sources of infection. It is mainly transmitted through air droplets, and can also be infected through skin wounds and birth canal. The incubation period is generally 2 -5 days. 02clinical presentation Scarlet fever is often associated with acute pharyngitis, with fever, sore throat, and swollen lymph nodes in the neck. If the patient does not exhibit symptoms of pharyngitis, the source of infection may be a GAS-infected wound or burn. The rash is one of the most important symptoms of scarlet fever, most of which appear on the 1st to 2nd day of onset, and occasionally as late as the 5th day. It starts from behind the ear, neck base and upper chest, and spreads to chest, back, upper limbs, and finally to lower limbs within 1 day. It takes several days for a few to spread to the whole body. The typical rash is a needle-cap-sized, dense and uniform punctate congestive rash scattered on the basis of the redness and congestion of the whole body. The hand pressure completely subsides and reappears after the pressure is removed. In the skin folds such as the armpits, cubital fossa, and groin, the rash can be seen in a dense linear pattern, called “Paper’s line”. The patient’s face is congested and flushed, and there may be a small rash, and the area around the mouth and nose is pale in comparison, which is called “perioral pallor”. In the early stage of the disease, the surface of the patient’s tongue is covered with white fur, and the nipples are red and swollen, protruding above the white fur, especially on the tip and edge of the tongue. After 2 to 3 days, the white coating begins to fall off, the tongue surface is smooth and fleshy red, and there may be superficial ruptures. When the rash occurs, the patient’s body temperature will be higher. When the rash spreads all over the body, the body temperature gradually drops, the symptoms of poisoning disappear, and the rash recedes. Peeling began within a week after the rash disappeared, and the order of the peeling sites was the same as the order of the rashes. The trunk is mostly bran-like peeling, and large pieces of membranous peeling are often seen in the thick skin of the palms and soles. Peeling generally lasts 2 to 4 weeks without leaving pigmentation. 03Clinical Evaluation and Diagnosis strong>When scarlet fever is suspected clinically, a detailed medical history investigation and physical examination are required. In patients associated with pharyngitis, the CENTOR criteria of fever, absence of cough, pharyngeal exudate, cervical lymphadenopathy, and patient age (usually <15 years) help determine the likelihood of strep throat. Peripheral blood examination showed that the white blood cell count and the proportion of neutrophils increased, and toxic granules were seen in the cytoplasm. The patients with purulent complications were higher, and the eosinophilia increased after the eruption. Culture of throat swabs or other foci of secretions and rapid streptococcus tests can detect the presence of GAS. It should be noted that for those over the age of 45Testing for rapid streptococcus in this population is controversial because it is more likely to be a carrier and the prevalence in this age group is lower. In younger patients with higher CENTOR scores, a rapid strep test is recommended to confirm infection and initiate treatment. The diagnosis of scarlet fever can be based on characteristic clinical manifestations, such as elevated white blood cell counts, GAS obtained from throat swabs, pus culture, and history of contact with patients with scarlet fever or angina. It needs to be differentiated from some viral diseases, such as measles, chicken pox, and hand, foot and mouth disease. 04Treatment and PreventionBecause scarlet fever is an infection caused by GAS, antibiotics are required for treatment, the main purpose is to quickly eliminate pathogenic bacteria and prevent complications caused by streptococcal infection. Penicillin or amoxicillin are first-line drugs. If the patient is allergic to penicillin, other antibiotics such as cephalosporins or clindamycin are available. Once the antibiotic treatment for scarlet fever is started, it should be taken strictly according to the doctor’s advice and cannot be stopped in advance. The prognosis of scarlet fever is good due to the use of antibiotics and health care measures, and after diagnosis and initiation of antibiotic therapy, patients can resume normal activities 24 hours after the fever subsides. There are currently no specific prevention and control measures such as vaccines for scarlet fever. Comprehensive prevention and control measures such as isolation treatment, monitoring, cluster epidemic investigation and disposal, and health education should be carried out around key places and key groups to reduce the incidence of Rate. Health education and awareness of disease prevention should be strengthened for children and adolescents under the age of 15 who are susceptible to scarlet fever. 
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