Diphtheria is an acute respiratory infectious disease caused by Bacillus diphtheriae, which is characterized by fever, asphyxia, hoarseness, barking cough, and white pseudomembrane in pharynx, tonsils and surrounding tissues. Severe cases can be complicated with myocarditis and nerve paralysis, and the symptoms of systemic poisoning are obvious. This disease often occurs in autumn and winter, and occasionally causes epidemic, especially for children aged 2-5. They all have lasting immunity after illness.
The incubation period of the disease is 1~6 days. According to the focus, it can be divided into pharyngeal diphtheria, laryngeal diphtheria, nasal diphtheria and conjunctival diphtheria. Among them, pharyngeal diphtheria is the most common, and laryngeal diphtheria has obvious symptoms of obstruction and suffocation, and the condition is critical.