Wheezing is the most common symptom of respiratory disease in infants and children, and about 1/3 of children with wheezing have at least their first episode within the first year of life, and the incidence of still having wheezing later is 30-60. The cause of wheezing in infants and children is complex, and there is no specific treatment, and the condition is repeatedly aggravated, and parents of children with wheezing question the effectiveness of treatment whenever it occurs. Repeated wheezing is not asthma, but it is closely related to asthma and has attracted widespread attention.
The characteristics of wheezing and asthma in infants and children are
1, the fastest growing prevalence
2. highest incidence of wheezing
3, the highest rate of medical care – 13 million under 5 years of age are affected
4. Hospitalization rate – 3 times higher than other children
5.Outpatient visits due to wheezing ≥ 3 million/year
6.Emergency care for wheezing 570,000 visits/year
7.There are >8.7 million prescriptions/year for wheezing
The most common cause of wheezing in infants and children is increased airway reactivity due to respiratory infections (respiratory syncytial virus, parainfluenza virus or bacteria), followed by gastroesophageal reflux, bronchial dysplasia, bronchial foreign bodies, and rare causes such as occlusive capillary bronchitis, abnormal pulmonary vascular and bronchial development, airway cilia malfunction, and cystic pulmonary fibrosis.
Why are there so many children with wheezing? The causes can be summarized in the following six areas.
1, infants and children have relatively narrow airways, soft mucous membranes and rich blood vessels;
2, soft cartilage, the lack of elastic tissue support lung elastic retraction force is relatively insufficient;
3, the relative lack of inter-alveolar (Kohn’s foramen) and bronchoalveolar (Lambert’s duct) connections;
4, the proportion of mucous glands in the epithelium is increased;
5, the virus stimulates the body to occur type I metamorphosis, in IgE involved in the bronchial wall mast cells degranulation release with active inflammatory mediators, causing bronchial smooth muscle spasm, resulting in airway narrowing, airflow obstruction;
6, after infection, the tiny capillary bronchi are congested and edematous, with more mucus secretion, together with the shedding of necrotic mucosal epithelial cells and blockage of the official lumen, leading to obvious emphysema and pulmonary atelectasis.
Depending on the presence or absence of risk factors, wheezing can be classified as temporary wheezing in infants, persistent early-onset wheezing, and late-onset wheezing. Temporary wheezing symptoms in infants tend to occur before the age of three years and are mostly associated with premature birth and parental smoking, with peak wheezing occurring within one year of age and mostly disappearing by the age of three. Persistent early-onset wheezing is most often caused by respiratory infections, is not associated with a personal or family history of atopic disease, and can persist until preschool age, with a high proportion of children still having symptoms by age 12.
As many parents say, wheezing does not require treatment when the child is young and will naturally heal on its own when it grows up. Late onset wheezing (also known as infantile asthma) is recurrent and persists into adulthood, often with a history of atopic illness. One study (Tucson Study) showed that children with recurrent wheezing (≥4 episodes) who had a parental history of asthma, a physician’s diagnosis of atopic dermatitis, allergen sensitization to ≥1 inhalant allergen as one of the primary risk factors, or two secondary risk factors of milk (egg, or peanut) allergy, wheezing unrelated to a cold, and eosinophilia >4% over 6 years and 51.5% over 3 years would In children without these risk factors, 91.6% within 6 years and 84.2% within 13 years did not develop asthma. This shows that the presence or absence of risk factors is the key to determine the occurrence of asthma, which means that genetic factors play an important role in the development of asthma in children, while environmental and social factors are also involved.
Since asthma is a syndrome, it has a variety of manifestations, i.e. different “phenotypes”, each of which is influenced by different factors, such as early or late onset, or severity, or allergen trigger, or viral trigger, or significant airway obstruction, or significant increase in nitric oxide, and since asthma phenotypes are so different, the response to treatment is also different. Since asthma phenotypes are so vastly different, they respond differently to treatment, and therefore, it is essential to emphasize individualized treatment of asthma in children. With wheezing so difficult to treat and the potential for asthma to develop, how can we treat and intervene? Conventional treatment includes short-term intravenous administration of systemic hormones such as methylprednisolone or dexamethasone, the use of rapid-acting (SABA) or short-acting beta2 agonists and long-acting theophylline (doxorubicin). Leukotrienes do not treat wheezing, but they reduce the chance of recurrent wheezing and may also prevent progression of wheezing to asthma.
Although there are different reports on the efficacy of inhaled ICS in the treatment, intervention and prevention of wheezing, in our long-term observations, inhaled ICS does have a good efficacy in the treatment of wheezing and is sometimes the “ultimate” treatment, choosing the right dose is the most critical, short-term use of higher doses is safe and effective. It has been reported that inhalation of ICS for one month did not show a reduction in the number of wheezing episodes over the next six months compared to the placebo group, but the shorter duration of one month alone does not show the benefits of ICS, as the best efficacy of ICS occurs after three months, so inhalation of ICS as a preventive and interventional measure should be chosen for three to six months.