Behandeling van astma bij kinderen op geleide van bronchiale hyperreactiviteit*

Objective

To assess, in children with asthma, whether a treatment strategy based on both symptoms and airway hyperresponsiveness (AHR) increased the number of symptom-free days and improved lung function, compared with a treatment strategy based on symptoms alone.

Design

Multicentre, double-blind, parallel-group, randomized, 2-year intervention trial.

Methods

210 children (aged 6-16 years) with moderately severe atopic asthma, selected on the basis of symptom scores and the presence of AHR, were randomized to one of 2 treatment strategies. At 3-monthly visits, symptom scores, forced expiratory volume in one second (FEV₁) and AHR (expressed in PD₂₀: the dose of methacholine producing a decrease of 20% in FEV₁ in a methacholine challenge test) were measured. In addition, medication (fluticasone 100-1000 μg/day with or without salmeterol 100 μg/day) was adjusted according to algorithms based on symptom scores alone (reference strategy, n = 104) or on the degree of AHR and symptom scores (AHR strategy, n = 102).

Results

After 2 years, no difference was found in the percentage of symptom-free days between treatment strategies. FEV₁ was significantly higher in children treated according to the AHR strategy than in children treated according to the reference strategy (a difference of 2.3% of the predicted value; p = 0.046). This difference was explained by a gradual worsening of FEV₁ in the reference strategy group in a subgroup of 91 children with AHR and few complaints at randomization. At the end of the study the difference in FEV₁ was 6% between the two treatment strategies in this subgroup (n = 91; p = 0.017).

Conclusion

Asthma treatment based on AHR showed no benefits in terms of the percentage of symptom-free days, but prevented the loss of lung function in allergic asthmatic children, especially those with few symptoms despite evident AHR.