Background: Allergen-specific immunotherapy (AIT) is proposed as a treatment option for asthma (AB) with prominent allergic rhinitis (AR), GINA 2022. We investigated the benefit of birch AIT for asthma control during the Betulaceae pollen season.

Methodology: Outpatient medical records of adult patients treated with birch AIT from 2 centres were retrospectively evaluated for i) aggravation of AB by Betulaceae allergens and subsequently for ii) effect of AIT on controlling their AR and AB in the pollen season. Medical records were reviewed by two allergists in parallel in a blinded manner, data merged, and unclear or discrepant cases were eliminated.

Results: 7% of AIT-treated patients did not complete their treatment due to none-serious adverse effects. In 31 patients, a conclusive evaluation of the AIT effect was obtained (Table). We observed substantial improvement (in symptoms, medication consumption and quality of life) in the vast majority of patients with birch pollen-related allergy treated with AIT. Superior effect was achieved in the control of allergic rhinitis (100%) and in the control on low-grade asthma without a persistent year-round component (over 80%). This supports the early initiation of birch AIT in patients with first-onset seasonal asthma.

Conclusion: Allergen immunotherapy with birch pollen represents a safe and effective personalized medicine approach for patients with seasonal asthma.