Research on the Treatment of Severe Community-acquired Pneumonia in Children

Inclusion Criteria: 1. 1 month-\< 18 years old. 2. Clinical diagnosis of community-acquired pneumonia (fever, cough, sputum, chest pain, dyspnea, abnormal breath sounds in the lungs, imaging pneumonia changes). 3. Meet any of the following: * (1) the general condition is very poor; * (2) refusal to eat or dehydration; * (3) Significantly increased respiratory rate (70 times/min \> infants, 50 times/min for older children\>); * (4) dyspnea (three concave sign, moaning, nasal flapping) * (5) hypoxemia (cyanosis, transcutaneous oxygen saturation\< 92% (not oxygenated)); * (6) Pulmonary infiltration≥ 2/3 lung or multilobar infiltration; * (7) There is a pleural effusion; * (8) Extrapulmonary complications Exclusion Criteria: 1. Systemic corticosteroids have been used to treat pneumonia before admission. 2. Use systemic glucocorticoids within 3 months before admission. 3. Hospital-acquired pneumonia. 4. Children with history of tuberculosis, branch expansion, tumors, immune deficiency, congenital heart, chronic pulmonary heart disease, kidney disease, severe malnutrition, recurrent respiratory infections, congenital bronchopulmonary dysplasia (BPD) and other underlying diseases. 5. Unconscious, need endotracheal intubation, children admitted to ICU. 6. Those who are allergic to the drugs or their preparation components involved in the study. 7. Those with hormonal contraindications: hypertension, diabetes, active peptic ulcer, adrenal hyperfunction, corneal ulcer, increased intraocular pressure, severe psychosis. 8. There is a current infection that is difficult to control with antibacterial drugs. 9. Children who are participating in other clinical trials. 10. The investigator believes that it is not suitable to participate in the study.