Clinical characteristics of chronic rhinitis patients with high vs low irritant trigger burdens.

BACKGROUND

Patients with chronic allergic rhinitis (AR) and nonallergic rhinitis (NAR) often experience irritant-induced symptoms. The clinical relevance of the magnitude of their symptoms in response to these nonspecific stimuli remains unclear.

OBJECTIVE

To determine the internal consistency and validity of an irritant index questionnaire (IIQ) and whether reclassification of physician-diagnosed rhinitis subtypes based on IIQ scores results in rhinitis subtypes with different clinical characteristics.

METHODS

Patients 18 to 65 years old with physician-diagnosed AR (n = 404), mixed rhinitis (MR; n = 129), or NAR (n = 123) completed an IIQ that rated rhinitis symptom severity in response to 21 nonallergic irritant triggers on a 1- to 10-point scale. Multistage sex-specific statistical analyses were performed using IIQ responses to reclassify physician-diagnosed AR, MR, and NAR into categories with high and low irritant burdens.

RESULTS

The IIQ demonstrated good internal consistency and cross-validation. After reclassification, 48% and 52% of patients with physician-diagnosed AR patients (n = 533) were categorized as having low-burden AR and high-burden AR, respectively, whereas 64% and 36% of NAR (n = 123) patients were categorized as having low-burden NAR and high-burden NAR, respectively. Reclassified high-burden AR and high-burden NAR patients were more likely to have a physician diagnosis of asthma and a greater number of self-reported rhinitis symptoms and perennial symptoms with seasonal exacerbations than reclassified low-burden AR and low-burden NAR patients, respectively (P < .01).

CONCLUSION

The IIQ resulted in significant reclassification of physician-diagnosed rhinitis patients into different diagnostic categories with unique clinical characteristics. Further studies are necessary to confirm the IIQ's utility as a tool for characterizing rhinitis patients in clinical practice and research.