Capillary bronchitis (hereinafter referred to as Mao Bronchitis) is a respiratory tract infection specific to infants and children under 2 years of age, and was originally called wheezing pneumonia because of the main clinical manifestation of wheezing symptoms. It is mainly a viral infection, more than 50% of which are respiratory syncytial virus infections, while others can be caused by adenovirus, influenza, parainfluenza virus, mycoplasma, etc. What is the relationship between trichinosis and asthma? Both hairy branch and asthma have typical wheezing symptoms, and some hairy branch is actually the first attack of asthma. If a child with hairy branch is atopic and has a family history of asthma, he or she should be on high alert for the development of asthma later in life. Children with hairy branch are prone to recurrent coughing and wheezing within six months of the disease, and asthma has been reported to occur in 1/2 of them in 2 to 7 years of follow-up. Risk factors include allergies, family history of asthma, congenital small airways, and respiratory syncytial virus infection. In some children, abnormal lung function persists for months to years. It can be seen that hairy branch and asthma are very closely related. Therefore, children with hairy branch must be treated actively and observed on regular follow-up. For example, it is important to enhance care, improve immune function, reduce respiratory infections such as colds, and avoid exposure to allergens and passive smoking.