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The following is a summary of “Comparative Evaluation of an Allergen Exposure Chamber and Nasal Allergen Challenge Versus In-Field Symptom Assessment in Patients With Allergic Rhinitis Triggered by Timothy Grass Pollen,” published in the March 2025 issue of European Journal of Allergy and Clinical Immunology by Wiacek et al. 

An allergen exposure chamber (AEC) exposes individuals to allergens in a controlled environment 

Researchers conducted a retrospective study to correlate clinical endpoints in allergic rhinitis patients sensitized to timothy grass pollen by comparing 3 methods: AEC, nasal allergen challenge (NAC), and natural exposure symptoms during the grass pollen season. 

They evaluated fifteen allergic subjects and twelve healthy controls in the ALLEC AEC, measuring allergic symptoms using total nasal symptom score (TNSS), acoustic rhinometry (AcR), peak nasal inspiratory flow (PNIF), and nasal discharge amount. The combined symptom medication score (European Academy of Allergy and Clinical Immunology (EAACI)-CSMS) was assessed for 14 days during the peak of the pollen season for in-field evaluation, while AcR, PNIF, and TNSS were used for NAC assessment. 

The results showed that all allergic individuals developed symptoms at the optimal pollen/allergen concentration in both AEC and NAC. Spearman’s rank correlation coefficient (P < 0.05) revealed significant correlations between symptoms assessed in AEC at 120 min and in NAC after 15 min with the EAACI-CSMS in-field. The correlation between AEC and in-field assessment was stronger than NAC, which showed weaker or no significant correlations. 

Investigators found that clinical endpoints assessed in the AEC and NAC significantly corresponded to the in-field efficacy analysis (EAACI-CSMS) during peak pollen exposure. The effect of NAC was not significant for all measured outcomes.

Source: onlinelibrary.wiley.com/doi/10.1111/all.16518