Influence of nasal provocation on FEV1/PEF of asthmatic patients with or without rhinitis

Rhinitis is a potential aggravating factor for asthma. Our objective was to evaluate if HDM nasal challenges would induce lung function changes, assessing any differences between asthmatics with and without rhinitis.

40 stable moderate persistent HDM allergic asthmatics, on inhaled steroids; 20 also had mild-moderate perennial HDM allergic rhinitis, treated only with oral cetirizine when needed. 10 non-allergic, non-asthmatic patients served as controls. Nasal provocation: standardised HDM extract, in powder-form, in sequentially increasing concentrations. Lung function: FEV1 before, 30 and 60' after the last nasal challenge. Peak-Expiratory-Flow (PEF) measurements were performed in the morning and evening, during the prior week and the 2 days following nasal provocation. MEDICATIONS ALLOWED: All patients maintained their inhaled steroids. Anti-histamines or b2-agonists in the preceding week constituted exclusion criteria.

Nine asthmatic, rhinitis patients showed statistically significant lung function decreases versus only two of the asthmatic non-rhinitic and none of the controls. No patient had any clinically significant asthma exacerbation.

Although not sufficient to induce asthma symptoms, nasal HDM provocation can induce slight lung function decrease, more frequently in patients who have both asthma and rhinitis than in patients with asthma without rhinitis.