Is response to allergen immunotherapy a good phenotypic marker for differentiating between allergic rhinitis and...

This study was designed to determine if patients with allergic rhinitis (AR) and mixed rhinitis (MR) subtypes have similar treatment outcomes after a full course of allergen immunotherapy (AIT). A historical pre- and posttreatment study design was used to identify all AR patients in a large allergy practice who started AIT in 2001 and completed at least a 3-year course. One reviewer compiled data through chart review using a standardized form that recorded allergic and nonallergic irritant triggers, symptoms, and medication requirements before and after completion of ≥3 years of AIT. Other than age, there were no significant differences in baseline demographic characteristics, allergic triggers, or rhinitis symptoms between the AR and MR groups. Both groups experienced reduced episodes of sinusitis after AIT. Although both groups also had a significant decrease in the mean number of rhinitis medications after AIT (p < 0.001), the reduction in number of medications was significantly greater for the AR versus the MR group (1.24 ± 1.09 versus 2.09 ± 1.55; p = 0.0023). AIT is a very effective treatment for AR and MR patients. However, these data support the classification of MR as a distinct rhinitis phenotype because MR patients required significantly more medications after a full course of AIT to control their nonallergic-induced symptoms.