[Rhinitis and asthma comorbidity in Spain: the RINAIR study]

Rhinitis and asthma share an inflammatory mechanism, epidemiological patterns, and symptoms that affect both the nose and the bronchi. The RINAIR study examined the prevalence and characteristics of rhinitis in asthma patients in Spain.

This prospective epidemiological study was carried out with the participation of 15% of Spanish respiratory medicine specialists sampled randomly from different geographic areas. The study population was composed of 703 asthmatic patients aged over 16 years who were enrolled between February and September 2005. Patient characteristics, prevalence of rhinitis, lung function, allergy test results, and treatment of rhinitis were analyzed.

Seventy-one percent (n=499) of the asthmatic patients had rhinitis. These patients were younger (43.8 years vs 55.4 years; P< .0001) and had less severe asthma (forced expiratory volume in 1 second [FEV1], 85.7% vs 79.7% [P< .001]) than asthmatic patients who did not have rhinitis. A correlation was observed between the severity of asthma and the severity of rhinitis (P< .001). Atopy was significantly associated with rhinitis (odds ratio, 6.25; 95% confidence interval, 4.3-9.1): 84% of atopic patients and 51% of nonatopic patients had rhinitis. Treatment of rhinitis was associated with an increase in FEV1 (P=.057), irrespective of sex, age, severity of asthma, or smoking.

Seventy-one percent of asthmatic patients who attended respiratory medicine clinics had rhinitis. These patients were younger and had milder asthma than asthmatics who did not have rhinitis. Furthermore, atopy was correlated with asthma associated with rhinitis. Treatment of rhinitis led to improved lung function. These findings highlight the need to study and treat the upper and lower respiratory tract as a single airway.