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Nonspecific bronchial reactivity in asthmatic children depends on severity but not on age
A Avital1, N Noviski, E Bar-Yishay
1Department of Pediatrics, Hadassah University Hospital, Mt. Scopus, Jerusalem, Israel.
Insights
In asthmatic children, bronchial reactivity to methacholine was inversely related to asthma severity. Age did not significantly impact methacholine response across a wide pediatric age range.
Area of Science:
- Pediatric Pulmonology
- Allergy and Immunology
- Respiratory Medicine
Background:
- Asthma is a chronic respiratory disease affecting children worldwide.
- Bronchial hyperresponsiveness is a hallmark of asthma.
- Methacholine challenge is a standard method to assess bronchial reactivity.
Purpose of the Study:
- To investigate the relationship between bronchial reactivity to methacholine and asthma severity in children.
- To determine the influence of age on methacholine-induced bronchial reactivity in pediatric asthma patients.
Main Methods:
- A cohort of 182 asthmatic children (1-17 years) were categorized into mild, moderate, and severe asthma groups based on treatment requirements.
- Bronchial reactivity was assessed using methacholine challenge tests.
- Age-specific testing methods included bronchial provocation with tracheal auscultation (BPTA) for younger children and spirometry (FEV1) for older children.
Main Results:
- Bronchial reactivity to methacholine showed a significant inverse correlation with asthma severity (p < 0.0001).
- Methacholine response was similar across different age groups (1-6, 7-11, 12-17 years) within each severity classification (p < 0.9965).
- No significant difference in reactivity was observed between moderate and severe asthma in older children, potentially due to corticosteroid treatment effects.
Conclusions:
- Age is not a significant factor influencing methacholine response in asthmatic children across a broad age spectrum.
- Bronchial reactivity is a reliable indicator of asthma severity in pediatric populations.
- Further research may be needed to elucidate the impact of long-term corticosteroid use on bronchial reactivity measurements.
Abstract:
Bronchial reactivity to inhaled methacholine was measured by the steady-state tidal breathing method in asthmatic children aged 1 to 17 yr. The children were divided into three clinical groups according to their minimal therapeutic requirements: mild asthma, children requiring infrequent treatment with inhaled beta-agonists (81 patients); moderate asthma, children requiring daily preventive treatment with either cromolyn sodium or slow-release theophylline (67 patients); and severe asthma, children requiring daily preventive treatment with oral or inhaled steroids (34 patients). They were also divided into three age groups: from 1 to 6 yr, tested by using bronchial provocation with tracheal auscultation (BPTA) to determine the methacholine concentration causing wheezing (PCW); and from 7 to 11 yr and 12 to 17 yr, using lung function testing to determine the concentration causing a 20% fall in FEV1 (PC20). For the whole group the mean level of bronchial reactivity to methacholine correlated inversely with the severity of bronchial asthma according to the minimal drug requirements (p less than 0.0001) and was similar over the whole age range (p less than 0.9965) for each severity grouping. In the older children the difference between moderate and severe asthma was not significant, but this may have been a result of the effect of corticosteroids in the severe group. We concluded that age has no significant effect on the methacholine response in asthmatic children over a wide age range.