Asthmatoid bronchitis is a clinical syndrome referring to a group of acute bronchial infections in infants and young children characterized by wheezing. The lung parenchyma is rarely affected. Some of these children may develop bronchial asthma.

bubble_chart Etiology

1. Infectious factors Various viral and bacterial infections can cause it. Common pathogens include respiratory syncytial virus, parainfluenza virus, influenza virus, adenovirus, nasal diseases virus, and Mycoplasma pneumoniae, among others. Most cases can be complicated by bacterial infections on the basis of viral infections.

2. Anatomical characteristics The trachea and bronchi of infants and young children are relatively narrow, and the surrounding elastic fibers are not fully developed. Therefore, their mucous membranes are prone to swelling and congestion due to infection or other irritations, leading to narrowed airways. The thick secretions are difficult to expectorate, resulting in wheezing sounds.

3. Allergic constitution factors Many infants and young children are infected with viruses, but only a small portion exhibit wheezing bronchitis symptoms. This suggests that the same virus can cause different pathophysiological changes and clinical manifestations in different individuals, closely related to intrinsic factors of the body. For example, recent studies have found that children with wheezing bronchitis caused by respiratory syncytial virus produce specific IgE antibodies, and the histamine concentration in their nasopharyngeal secretions is significantly higher than in children with the same infection but no wheezing symptoms. Their relatives often have a history of allergic diseases such as allergic rhinitis, urticaria, and asthma. About 30% of affected children have a history of eczema, and serum SIgE levels are often elevated.

The characteristics are as follows: ① The age of onset is relatively young, mostly seen in children aged 1 to 3. ② It often occurs secondary to upper respiratory tract infections, with most cases being mild, presenting with low-grade or grade II fever, and only a few children developing high fever. Prolonged expiration is accompanied by wheezing and coarse rales, with no obvious paroxysmal喘息发作. ③ After treatment, the above symptoms alleviate by the 5th to 7th day. ④ Recurrence in some cases is mostly related to infections. ⑤ The short-term prognosis is generally good, with fewer recurrences by ages 3 to 4 and gradual recovery. However, some cases may develop into bronchial asthma in the long term. Beijing Children's Hospital conducted a 4- to 21-year retrospective follow-up of 594 cases of asthmatic bronchitis from 1987 to 1989, finding that 41% progressed to asthma, of which 61.8% had recovered, while 38.2% still experienced asthma发作. Those with a history of allergies, higher eosinophil counts, or elevated serum IgE levels often developed bronchial asthma. According to the Pediatrics Department of Tianjin Medical College and other institutions (1989), 146 cases of asthmatic bronchitis and bronchial asthma were considered the same disease, as their genetic history, allergy history, serum IgE levels, and pulmonary function were very similar. The Pediatrics Department of Xi'an Medical University (1988) also suggested that unexplained recurrent喘息发作 in children under 3 years old should be considered infantile asthma, which may represent the same disease manifesting differently at two age stages compared to childhood asthma. The 1988 National Infantile Asthma Conference proposed diagnostic criteria (scoring method) for infantile asthma: For children under 3 years old with recurrent喘息发作, the scoring principles are: ① 2 points for recurrent喘息发作 ≥3 times after infantile bronchiolitis or asthmatic bronchitis, ② 2 points for wheezing sounds in the lungs, ③ 1 point for sudden onset of喘息症状, ④ 1 point for other过敏史 in the child, ⑤ 1 point for a family history of eczema, dermatitis, or asthma in first- or second-degree relatives. A total score >5 points diagnoses infantile asthma, while喘息发作 occurring only twice or a total score ≤4 points leads to a preliminary diagnosis of asthmatic bronchitis, with continued follow-up observation.

1. General Treatment Regarding rest, diet, and adjustments to indoor temperature and humidity, please refer to "Upper Respiratory Tract Infection." Infants should frequently change their lying positions to facilitate the discharge of respiratory secretions. When frequent {|###|}cough{|###|} interferes with rest, antitussives may be administered, but excessive dosing should be avoided to prevent suppression of the cough reflex needed to expel secretions. If acute bronchitis causes spasms leading to dyspnea, mild cases may be treated with the following {|###|}Chinese medicine{|###|} therapy for "excessive heat panting," while severe cases should be managed similarly to bronchiolitis and bronchial {|###|}asthma{|###|}.

2. {|###|}Chinese Medicine{|###|} Therapy In {|###|}Chinese medicine{|###|}, this condition is referred to as {|###|}cough due to external contraction{|###|}. Depending on the pathogenic factors, it is clinically classified into {|###|}wind-cold cough{|###|}, wind-heat {|###|}cough{|###|}, and excessive heat panting. Treatment focuses on {|###|}dispersing wind and dissipating cold{|###|}, {|###|}clearing heat and ventilating lung{|###|}, and reducing heat to calm panting. Clinical differentiation should guide the treatment.

(1) {|###|}Wind-cold cough{|###|}: Characterized by sudden {|###|}cough{|###|}, rapid and frequent dry cough, thin phlegm, {|###|}stuffy nose{|###|}, clear nasal discharge, itchy throat, or accompanying {|###|}headache{|###|}, {|###|}aversion to cold{|###|}, or absence of fever, white tongue coating, and floating pulse. Treatment aims to {|###|}release the exterior with pungent-warm{|###|} herbs and dissipate cold to relieve cough. Commonly used formulas include modified {|###|}Apricot Kernel and Perilla Powder{|###|}.

(2) Wind-heat {|###|}cough{|###|}: Manifested by unproductive {|###|}cough{|###|}, thick yellow phlegm, red throat, dry mouth, {|###|}stuffy nose{|###|} with yellow nasal discharge, or accompanying fever, sweating, slightly yellow-white {|###|}tongue coating{|###|}, and rapid floating pulse. Treatment involves {|###|}releasing the exterior with pungent-cool{|###|} herbs and {|###|}ventilating lung and relieving cough{|###|}. Commonly used formulas include modified {|###|}Mulberry Leaf and Chrysanthemum Decoction{|###|}.

(3) Excessive heat panting: In addition to the above symptoms, the child exhibits high fever and labored breathing. Treatment focuses on {|###|}ventilating lung and resolving phlegm{|###|}, {|###|}downbearing counterflow and relieving panting{|###|}. Commonly used formulas include modified Ma Xing Shi Gan Tang.

Example prescription: {|###|}Ephedra{|###|} 3g, {|###|}Bitter Apricot Seed{|###|} 6g, raw {|###|}Gypsum{|###|} 15g, {|###|}Liquorice Root{|###|} 3g, {|###|}Indigo{|###|} 3g, {|###|}cultivated purple perilla fruit{|###|} 6g, {|###|}radish seed{|###|} 9g. Additional herbs (1–2) may be selected based on symptoms: ① For severe {|###|}exterior pathogen{|###|}, add {|###|}Chrysanthemum Flower{|###|} 9g, fresh {|###|}Reed Rhizome{|###|} 15g. ② For severe heat, add {|###|}Skullcap Root{|###|} 6g, {|###|}Lonicera{|###|} 9g, {|###|}Forsythia{|###|} 9g. ③ For severe {|###|}cough{|###|}, add {|###|}Peucedanum{|###|} 9g or {|###|}stemona root{|###|} 9g. ④ For severe panting, add {|###|}Curcuma Root{|###|} 6g, Ginkgo 9g, or raw {|###|}hematite{|###|} 15g. ⑤ For excessive phlegm, add {|###|}Pepperweed Seed{|###|} 9g, Trichosanthes seed 9g.

3. Other Treatments Sometimes, an appropriate dose of ipecac syrup is needed: 2–15 drops for infants and 1–2ml for older children, administered 4–6 times daily, to facilitate expectoration. A 10% ammonium chloride {|###|}solution{|###|} has a similar effect, with a {|###|}dose{|###|} of 0.1–0.2ml/kg per dose. For bacterial infections, appropriate antibiotics may be selected. Additionally, ultrashort wave or ultraviolet radiation therapy may be used for prolonged bronchitis.

bubble_chart Prevention

As mentioned in the previous section, for children with asthmatic bronchitis, attention should be paid to analyzing the family and the child's own allergy history, eosinophil examination, and serum IgE levels. If bronchial asthma is suspected, asthma prevention and treatment measures should be implemented as early as possible.

bubble_chart Differentiation

The similarities and differences of wheezing-like diseases in the lower respiratory tract of infants and young children are summarized in Table 24-11 for reference in differential diagnosis.

Table 24-11 Differential Diagnosis of Wheezing in the Lower Respiratory Tract of Children in the First Year