Infants and young children have poor defenses and immature lung development, so the incidence is highest within 2 years of age, mostly secondary to upper respiratory tract infections and acute infectious diseases, and is most common in winter and spring. Drug-induced cough is commonly associated with ACEI and beta-blockers, with an incidence of about 15%. It is characterized by a barking or goose-cold, irritating dry cough, often accompanied by a clear throat sound. What are the differential diagnoses for chronic cough and wheezing in winter and spring? 1, tuberculosis: there are mostly symptoms of systemic toxicity, such as low fever in the afternoon, night sweats, fatigue, weight loss, insomnia, palpitations, etc. X-ray chest film shows that the lesions are mostly at the tip of the lung or above and below the clavicle, with uneven density and slow dissipation, and can form cavities or disseminate within the lung. Mycobacterium tuberculosis can be found in the sputum. General antibacterial drug treatment is ineffective. 2.Lung cancer: Most of them have no symptoms of acute infection poisoning, sometimes hemoptysis or blood in sputum, which may be accompanied by obstructive pneumonia, and the effect may be poor after antibiotic treatment. On the image, enlarged lymph nodes in the lung hilum or pulmonary atelectasis can be seen. If the inflammation in the lungs is not easily absorbed after antibiotic treatment, or if pneumonia reappears in the same area after temporary absorption, close follow-up is indicated. For patients with smoking history and older age, further chest CT, bronchoscopy and sputum exfoliation cell examination can be performed if necessary to clarify the diagnosis. 3. Acute lung abscess: The early clinical manifestations are similar to those of Streptococcus pneumoniae pneumonia. However, as the disease progresses, a large amount of purulent sputum can be coughed up, which is a special characteristic of lung abscess. x-ray chest film shows pus cavity and air-fluid flat, which can be easily distinguished from pneumonia. 4, pulmonary thromboembolism: most of the risk factors of venous thrombosis, such as thrombophlebitis, cardiopulmonary disease, trauma, surgery and tumor history, hemoptysis, syncope, dyspnea and other symptoms can occur, X-ray chest film shows regional pulmonary texture reduction, sometimes the tip of the wedge-shaped shadow pointing to the hilum is visible, arterial blood gas analysis is common hypoxemia and hypocarbia. d-dimer, CT pulmonary arteriogram D-dimer, CT pulmonary arteriography, radionuclide lung ventilation/perfusion scan, and MRI may help in differentiation. 5. Non-infectious pulmonary infiltrates: Non-infectious pulmonary diseases such as interstitial fibrosis, pulmonary edema, pulmonary atelectasis, pulmonary eosinophilic infiltrates and pulmonary vasculitis also need to be excluded.