The etiology of capillary bronchitis is mainly respiratory syncytial virus, which can account for 80% or more; others are adenovirus, parainfluenza virus, rhinovirus, and influenza virus in that order; a few cases can be caused by Mycoplasma pneumoniae; after infection with the virus, the tiny capillary bronchioles become congested, edematous, and have increased mucus secretion, which, together with the shedding of necrotic mucosal epithelial cells and blockage of the lumen, leads to significant emphysema and pulmonary atelectasis. Inflammation can often involve the alveoli, alveolar wall and interstitial lung, so it can be considered a special type of pneumonia, capillary bronchitis, different from general bronchitis or bronchiectasis, with clinical symptoms like pneumonia, but with wheezing as the main cause. This disease occurs mostly in children under 2.5 years of age, 80% within 1 year of age, mostly under 6 months of age. Clinical manifestations: typical capillary bronchitis often occurs after 2-3 days of upper respiratory tract infection, with a persistent dry cough and fever, with a moderate to low fever, characterized by episodes of wheezing, the condition is more severe 2-3 days after the onset of wheezing, breathing significantly faster during episodes of wheezing, up to 60-80 times per minute or more, with prolonged expiration and expiratory wheezing; children with severe disease clearly show In severe cases, the child may exhibit nasal stirring and “trigeminal signs” (i.e., supraclavicular fossa, suprasternal fossa and epigastric depression during inspiration), pale face, blue around the mouth, or cyanosis, and the child is often irritable and moaning; in more severe cases, the child may be combined with heart failure or respiratory failure, and most cases can be relieved after treatment, and death rarely occurs. Symptoms of the disease: The disease is most common in children under 1 year of age, especially in infants under 6 months of age. The disease can develop throughout the year, but is more common in winter and spring: 1, the initial fever, chills, headache, dry throat, etc. 2. The main symptoms are coughing and coughing up sputum. Treatment principles: children should be sent to hospital promptly after the onset of the disease, because capillary bronchitis is mostly caused by viral infections, so the early onset of the disease generally does not require antibiotic treatment. If there is a suspicion of secondary bacterial infection in the later stages of the disease, antibiotics can be used to treat the symptoms, which can be summarized as “sedation and coughing”. In severe cases, nebulized inhalation can be used to keep the respiratory tract open by timely aspiration. Disease prevention: First of all, pay attention to children’s hot and cold, don’t dress too hot, and let them have proper cold-tolerance exercise. When the temperature is high, don’t just think about the child being cold, but more importantly, pay attention to not letting the child get hot at any time, so that he or she doesn’t sweat and get a cold more easily. If your child has a cold, give some medicine as early as possible to treat it, so as not to delay it.