Short-term efficacy of nebulized budesonide for allergic airway inflammation in young children and dynamic changes in fractional exhaled nitric oxide (FeNO): a retrospective cohort study.

BACKGROUND

Allergic airway inflammation in young children with recurrent wheezing may precede asthma. Fractional exhaled nitric oxide (FeNO) may reflect type 2 airway inflammation.

OBJECTIVE

To evaluate the short-term effectiveness and safety of nebulized budesonide and dynamic FeNO changes in children aged 6 to 36 months.

METHODS

We retrospectively analyzed 548 children treated between January 2023 and February 2025, with follow-up through June 2025. Children receiving standard care plus nebulized budesonide (n = 286) were compared to those on standard care alone (n = 262). Outcomes included clinical response, symptom-resolution time, serial FeNO, inflammatory biomarkers, three-month recurrence and adverse events.

RESULTS

Overall response at day 7 was higher with budesonide than in the control group (92.7% vs. 80.9%; χ2 = 16.71, P < 0.001), and systemic corticosteroid rescue was less frequent (1.05% vs. 4.20%; Fisher exact P = 0.028). Wheeze resolution time was shorter (3.2 ± 1.1 vs. 5.1 ± 1.6 days; P < 0.001). FeNO decreased more in the budesonide group from baseline to day 28 (22.6 ± 6.4 to 9.8 ± 3.2 ppb) than in controls (22.4 ± 6.7 to 14.5 ± 4.6 ppb; P < 0.001 for change). Three-month recurrence was lower with budesonide (14.7% vs. 27.5%; χ2 = 13.59, P < 0.001), with no increase in adverse events.

CONCLUSION

Nebulized budesonide added to standard care was associated with improved short-term clinical outcome, greater FeNO reduction, and lower three-month recurrence in young children with allergic airway inflammation.