I. What is asthma?
Bronchial asthma (asthma for short) is a chronic inflammatory disease of the airways. Chronic inflammation develops with increased airway reactivity, and when exposed to various risk factors, airway obstruction and airflow obstruction (caused by bronchoconstriction, mucus plug formation and increased inflammation) occur, and recurrent episodes of wheezing, dyspnea, chest tightness and coughing occur, especially at night and in the early morning. Although asthma attacks or exacerbations are phasic, the inflammation of the airways is long-lasting.
II. Is asthma prevalent in children?
The prevalence of asthma has increased significantly worldwide in recent years compared to previous years. The epidemiological findings on the prevalence of asthma around the world show that the prevalence of asthma in children ranges from 3.3% to 29.0% and in adults from 1.2% to 25.5%. This indicates that the prevalence of asthma among children in China is on the rise. Therefore, asthma has become one of the serious public health problems that endanger the health of children in China.
Do you understand the natural course of asthma?
Asthma can occur at any age, 30% of patients have symptoms at the age of 1 year, 80%-90% of children with asthma have their first symptoms before the age of 4-5 years, and its course and later severity are difficult to predict, most of them are mild to moderate, and a few severe refractory asthma are mostly perennial attacks. The relationship between the early age of onset of asthma and prognosis is not well understood. Most children with severe asthma have wheezing in the first year of life and have a history of allergic disease and family asthma. The prognosis for children with mild to moderate asthma is fair, with long-term studies indicating that 50% of children with this type of asthma have remission of symptoms by age 10 to 20 years, but may still have attacks in adulthood. Severe hormone dependence (especially with frequent oral or intravenous hormone control of exacerbations without regular treatment) and frequent hospitalization convert 95% to adult asthma, when it is not clear when the hyper-reactive state of the airways disappears. The death of asthma is related to untimely diagnosis and poor treatment. In developed countries abroad, the death rate has decreased significantly in recent years due to the promotion of inhaled hormone therapy and management education, but there are no statistical results in China yet.
IV. What are the risk factors of asthma?
1.Internal factors
(1) Allergic family history and personal allergy factors: allergic family history refers to family history of asthma, allergic rhinitis, eczema and other diseases; personal allergy history refers to those who have suffered from allergic rhinitis and/or eczema, or have any food or drug allergy are considered to have personal allergy history. Studies have shown that a child with one parent with asthma is 25% likely to have asthma; if both parents have asthma, 50% of the children are likely to have asthma. Allergy is an epidemiological group study that shows that 50% of people with asthma have allergies. Familial studies suggest that when both are present, the risk of asthma in their relatives is significantly increased.
(2) Gender: Asthma in childhood is more common in males than females, probably because of the narrower airways and high airway tone in boys, factors that increase airflow limitation due to various injuries in boys. However, this sex-driven difference in onset gradually disappears after puberty. In contrast, asthma symptoms in women worsen during menstruation, pregnancy, and menopause due to sex hormones, leading to an increased prevalence of asthma in women during and after puberty.
(3) Obesity: In recent years, epidemiologists in the United States have noted that the prevalence of obesity among 20-74 year olds in the United States increased from 13.4% in 1960 to 27.6% in 1962, and that obesity among women increased from 15.8% in 1980 to 33.2% in 1996, while the prevalence of asthma increased by 73.9% from 1980 to 1996. Some evidence also shows that there is a relationship between high body mass index and high prevalence of asthma.
2.External causes
(1) Indoor allergens: Indoor allergens include house dust, animal allergens, cockroach allergens and fungi. Indoor carpets, air conditioners or humidifiers are ideal habitats for dust mites, cockroaches and other insects, as well as places where bacteria and molds can grow. ① House dust is composed of a variety of organic and inorganic compounds, including fibers, mold spores, pollen, insects, insect feces, mammalian dandruff, mites and mite feces. ②Animal allergens: domesticated animals release allergens through their secretions, excretions and fur. ③ Cockroach allergens are even more common than dust mite allergies in some areas, and most cockroaches are suitable for living in tropical environments; however, they can also breed in air-conditioned rooms. The carcass, dander, feces and eggs of the mantis are all strongly allergenic. ④Fungi: Fungi grow in cooling, heating, and humidification systems, and indoor humidifiers promote fungal growth and increase the risk of airborne exposure. The most common indoor fungi are Penicillium, Aspergillus, Streptomyces, Mycosphaerella and Candida. Can be determined by skin allergen testing.
(2) Outdoor allergens: the most common is pollen. Pollen allergens mainly come from trees, grasses and weeds. In general, tree pollen is predominant in early spring, grass pollen in late spring and summer, and weed pollen in summer and fall. It is associated with worsening asthma, increased symptoms, airway reactivity and airway inflammation, and can cause seasonal allergic rhinitis and asthma attacks. It can be measured by skin allergen testing.
(3) Diet structure: The diet structure of the pediatric population has an increasing influence on the development of asthma. Studies have shown that cow’s milk feeding or consumption of soy protein is more susceptible to wheezing disease in childhood than breastfeeding. In particular, a Western diet characterized by high protein, high fat and increased intake of foods with a long shelf life often leads to an increased prevalence of asthma or allergic diseases. In recent years, the increased use of infant formula and food additives has led to asthma attacks. It has been shown that breastfeeding can reduce the occurrence of asthma because breast milk is rich in secretory immunoglobulin A, which can increase the infant’s mucosal epithelial resistance to infection and help reduce the occurrence of virus-induced wheezing lower respiratory tract disease, which is unmatched by any formula.
(4) Respiratory infection infection: Epidemiological evidence confirms that acute respiratory viral infections can induce acute attacks of asthma in adults and children. Respiratory syncytial virus, parainfluenza virus and rhinovirus are the main viruses causing wheezing in infants and children. Bacterial infections in infancy and childhood, especially Chlamydia pneumoniae, play an important role in the development of asthma in adulthood.
(5) Passive smoking: For pediatric patients, passive smoking increases the incidence of lower respiratory tract disease, whether during pregnancy, infancy, or childhood. The smoke from burning cigarettes is more toxic than the smoke inhaled by the smoker and is particularly likely to irritate the respiratory mucosa. Children born to mothers who smoke during pregnancy or in combination with family members who smoke have an increased incidence of asthma and wheezing symptoms. Maternal smoking during infancy can cause four times more wheezing symptoms in the first year of life than in the average child.
(6) Other factors that cause asthma attacks: rhinitis and sinusitis are often associated with asthma attacks, and proper treatment of each of these conditions can improve asthma. Gastroesophageal reflux can also cause asthma attacks, especially in children. When the reflux is corrected, asthma will also improve.
V. What are the main clinical manifestations of asthma?
The typical symptoms of bronchial asthma are cough, chest tightness, wheezing and dyspnea, especially when these symptoms are recurrent and often worsen at night or early in the morning.
VI. How to detect asthma early as a parent?
The non-specific nature of asthma symptoms often leads to a variety of diagnoses when a patient visits the doctor. Many children are treated with inappropriate series of antibiotics and cough medications for the diagnosis of bronchitis and wheezing pneumonia. Therefore, it is important to establish the correct diagnosis of asthma in order to provide appropriate treatment.
As a parent, asthma should be highly suspected if the child is found to have any of the following signs or symptoms.
(1) Frequent wheezing episodes – more than once a month.
(2) Activity-induced cough or wheezing.
(3) Cough, especially at night without an infectious component.
(4) Symptoms appear or worsen with exposure to or in the presence of: fur-bearing animals, chemical aerosols, temperature changes, house dust mites, medications (aspirin, etc.), exercise, pollen, respiratory infections, smoke, violent mood swings.
(5) Children with colds that repeatedly “progress to the lungs” or last more than 10 days before recovery.
(6) Symptoms are reduced after taking asthma treatment medication.
(7) What tests are needed for children with suspected asthma?
(1) Allergen testing.
Mainly through skin allergen prick and food allergen screening to know whether allergens are present.
(2) Measurement of pulmonary function.
Pulmonary function tests can be performed to find out if there is airflow limitation.
(3) Airway hyperresponsiveness test.
It is mainly used for pulmonary function measurement within the normal range, and the presence of airway hyperresponsiveness can be observed by excitation test (acetylcholine, histamine or exercise test).
VIII. What are the drugs used to treat asthma and why should asthma be treated long-term?
Asthma attacks (or exacerbations) are phasic, but the inflammation of the airways is long-lasting. Acute attacks of asthma are mainly given with bronchodilators, oral hormones or intravenous application of hormones and theophylline drugs, and hospitalization is required if necessary. Asthma is a chronic inflammatory disease, so parents should be guided to apply anti-inflammatory therapy as early as possible, especially inhaled hormones and oral leukotriene receptor antagonists, which are now internationally used, i.e., the GINA program. However, the treatment rate of inhaled hormones in China is still very low, probably because on the one hand, people generally believe that inhaled treatment is more expensive and both doctors and patients think that inhaled treatment is a heavy burden. In fact, some studies have shown that aspiration treatment is not more expensive than non-aspirated treatment and may even save money. Some studies from developed and developing countries have shown that inhaled corticosteroids improve asthma control and reduce hospitalization, thus greatly reducing medical costs. On the other hand, since parents do not know much about inhaled hormones and think that long-term inhaled hormones are equivalent to long-term oral hormones, which will affect the growth and development of children, the treatment of asthma with inhaled hormones has yet to be further publicized and promoted in pediatrics in China.
9.How to do a good job of asthma prevention?
1. The most important thing is to listen to the treatment plan of asthma specialists.
Timely and quantitative preventive treatment, avoid randomly stopping and reducing the dosage. Usually, children should be seen again 1-3 months after the initial visit and once a month after the asthma is under control, and should be seen immediately in case of exacerbation.
(1) If asthma is not controlled after the implementation of the current treatment regimen, escalation of therapy is required and improvement should be seen within 1 month in general. However, medication technique, adherence and risk factor avoidance should be checked first.
(2) If the asthma is controlled for at least 3 months, the specialist should be asked at the hospital if the treatment can be downgraded and the medication should not be reduced or stopped without authorization; this process is lengthy and is the key to successful asthma control.
(3) If the child has obvious allergens, desensitization therapy can be given to get rid of asthma completely.
2. On the other hand, to improve asthma control and to reduce the need for medical treatment.
Patients should take steps to avoid risk factors that cause asthma symptoms.
(1) House dust mites: Wash sheets and blankets weekly in hot water and dry them in a dryer or in the sun, take away carpets, especially in bedrooms, and replace them with hard straight floors.
(2) Fur animals: Remove them from the home or at least keep them out of the bedroom area. Bathing from pets.
(3) Indoor mold: Reduce indoor humidity and clean all wet areas frequently.
(4) Outdoor pollen, dust mites or mold: During peak pollen season, stay indoors with doors and windows closed, or if unavoidable, preemptively give a pollen blocker to apply to nasal passages or wear a mask.
(5) Food, additives or drugs: For infants and young children, breastfeed as much as possible, do not eat small foods, and avoid allergic foods, avoid high protein, high fat diet, and improve the diet structure.
Finally, I believe that as long as parents do these things, asthma can be completely well controlled.