No increase in non-specific bronchial hyperreactivy in patients with cypress pollen allergy during the pollen season

Background: A previous study has shown that patients with cypress pollen allergy have a much higher prevalence of cough during the pollen season compared to patients suffering from grass pollen allergy. Besides, non specific BHR has been shown to increase in grass-pollen allergic patients during the pollen season. To investigate whether cough is an indicator of bronchial hyperractiviy (BHR), we compared non specific BHR outside and during the pollen season.Methods: We selected 31 patients (mean age: 39.7+/-12.3 yrs) suffering from cypress pollen allergy defined by a rhino-conjunctivitis occurring during the cypress pollen season and positive skin tests to cypress extracts. BHR was assessed using cumulative methacholine challenge up to 2,500 µg and measurement of serial FEV1 measurements. We compared the mean drop in FEV1 at the completion of the challenge test.Results: The mean drop in FEV1 was equal to 11+/- 10.6% during the pollen season and 10.0 +/- 10.6% outside the pollen season, a non significant difference. Seven patietns out of 31 demonstrated a 20% or more drop in FEV1 during the challenge outside the pollen season and the same number during the pollen season, but the positive tests did not necessarily occurred in the same patients. Patients reporting cough during the pollen season (45.8%) did not exhibit a higher fall in FEV1 during the challenge test (p<0.9).Discusion and conclusion: Patients suffering from cypress pollen allergy have a high prevalence of ...
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: 5.3 Allergy and Immunology Source Type: research