Related Experiment Videos
Lung function studies in children with allergic rhinitis
Insights
Children with allergic rhinitis show a tendency towards subclinical bronchospasm after exercise, even in pollen-free seasons. This finding, related to functional residual capacity (FRC), is not clinically significant.
Area of Science:
- Pediatric Pulmonology
- Allergy and Immunology
- Respiratory Physiology
Background:
- Seasonal allergic rhinitis affects children, with potential subclinical respiratory impacts.
- Previous research indicates possible airway hyperresponsiveness in allergic individuals.
Purpose of the Study:
- To investigate lung function changes in children with seasonal allergic rhinitis during pollen and pollen-free seasons.
- To assess for subclinical bronchospasm, particularly after exercise, in these children.
Main Methods:
- Clinical examination and pulmonary function tests (including FRC and lung clearance index) were performed.
- Exercise challenge tests were conducted in the pollen-free season.
- Salbutamol inhalation was administered post-exercise to evaluate bronchospasm.
Main Results:
- During the pollen season, a slight increase in functional residual capacity (FRC) and a decrease in lung clearance index were observed.
- Exercise tests revealed a small increase in the volume of trapped gas (VTG), suggesting subclinical small airway spasm.
- Salbutamol effectively reduced VTG, confirming the presence of reversible bronchospasm.
Conclusions:
- Children with seasonal allergic rhinitis exhibit a tendency towards exercise-induced subclinical bronchospasm, even outside the pollen season.
- This exercise-induced bronchospasm is of minimal clinical significance as lung function remains within normal or better-than-predicted limits.
Abstract:
Thirty carefully selected children with seasonal allergic rhinitis but without history or signs of lung involvement were examined clinically and by lung function tests during the pollen season as well as in the pollen-free season. During the pollen-free season the children had - if anything - slightly better lung function than a healthy control material. During the pollen season the only change was a slight increase in FRC and a decrease in lung clearance index, directly proportional to the change in FRC. Sixteen of the children performed an exercise test in the pollen-free season. A small increase in the volume of trapped gas (VTG) was noted, indicating a subclinical spasm in small airways. Salbutamol inhalation after exercise reduced VTG below base-line values, indicating disappearance of subclinical bronchospasm. Hay fever children thus have a tendency towards bronchospasm after, exercise in the pollen-free season, which, however, is of no clinical importance, as their VTG also after the exercise was less (better) than the predicted normal.