Analyzing phenotypes post-exposure in allergic rhinitis in the environmental exposure unit

Previous studies have defined clinical phenotypes of allergic rhinitis (AR) after allergen exposure using the time course of the total nasal symptom score (TNSS).

To validate previously proposed AR phenotypes across different allergens (birch, grass, ragweed, and house dust mite) after exposure in the environmental exposure unit.

The Analyzing Phenotypes Post-Exposure in Allergic Rhinitis (APPEAR) database comprises 153 participants from environmental exposure unit studies conducted between 2010 and 2021 by Kingston Allergy Research. TNSS, nasal congestion symptom scores, and percent change in peak nasal inspiratory flow from baseline (%ΔPB) were recorded for each participant. Participants were phenotyped using previously described criteria.

There were 65 participants (42.5%) classified as early-phase responders (EPRs), 58 (37.9%) as protracted EPRs (pEPRs), 13 (8.5%) as dual responders (DRs), and 17 (11.1%) as low responders (LoRs). Significant negative correlations exist between TNSS and %ΔPB (r = -0.99, P < .0001) and nasal congestion symptom score and %ΔPB (r = -0.99, P < .0001). At the beginning of the late-phase AR response (6-7 hours), pEPRs had significantly higher TNSS compared with EPRs, DRs, and LoRs (P < .0001). By the end of the study (up to 12 hours), DRs and pEPRs had significantly higher TNSS compared with EPRs and LoRs (P < .0001). Visible validity and statistical validity between the phenotypes were also confirmed by assessing participants' mean TNSS and mean %ΔPB over time when grouping by phenotype.

This study confirms that distinct phenotypes exist in the late-phase AR response among different allergens and in a greater sample size than described previously, which could provide clinical benefit.