Methacholine bronchial challenge effects on nasal symptoms and function in patients with allergic rhinitis.

BACKGROUND Allergic rhinitis and asthma may be associated, bronchial hyperreactivity (BHR) is quite common in AR patients. It has been reported that allergen bronchial challenge induces nasal inflammation. Methacholine (MCH) is a stimulus able to elicit BHR. There is no study that investigated the effect of MCH bronchial challenge on the nose. OBJECTIVE The aim of this study was to evaluate whether MCH bronchial challenge is able to induce changes in nasal symptom perception and nasal function in patients with AR. METHODS 122 patients (117 males, median age 28 years) suffering from AR were evaluated. Values for bronchial function (FVC, FEV1, FEF25-75, and FEV1/FVC ratio), MCH bronchial challenge, VAS for nasal and bronchial symptoms, and nasal airflow and resistance were assessed. RESULTS 23 patients (18.9%) had BHR. MCH bronchial challenge induced a significant reduction of nasal obstruction perception (p<0.001), but did not affect the nasal function. Most of patients (91) did not perceive impairment of respiration. The perception of nasal obstruction was strongly related to the AR duration (r=0.65). The highest values of both baseline rhinoVAS and Δ bronchial VAS predicted BHR (OR 1.7 and 2.9 respectively). CONCLUSIONS The present study demonstrates that in AR patients MCH bronchial challenge does not substantially affect nasal symptoms and function, also in subjects with an acute bronchospasm, such as in BHR patients. However, severity of nasal obstruction perception might predict BHR.