Phenotyping asthma in the elderly: allergic sensitization profile and upper airways comorbidity in patients older than 65 years.

BACKGROUND

Data about allergic rhinitis in elderly patients with asthma are lacking.

OBJECTIVE

To investigate the presence of rhinitis and the role of sensitization of airborne allergens in elderly patients with asthma.

METHODS

This was a multicenter cross-sectional study involving subjects at least 65 years old with asthma. Demographic features, comorbidities, and the presence of allergic respiratory disease were retrieved through interview. Skin prick tests for common allergens were performed. Associations of demographic and clinical features were evaluated in relation to asthma control and forced expiratory volume in the first second less than 80% in the total population and in the subgroup with features resembling chronic obstructive pulmonary disease.

RESULTS

Of 368 elderly subjects with asthma, 101 had features resembling chronic obstructive pulmonary disease. Rhinitis was present in 59.0% of subjects (allergic rhinitis in 47.6%), with an age of onset significantly different from that of asthma (49 ± 18 vs 57 ± 18 years). At least 1 sensitization was observed in 52.4% of subjects, more frequently for house dust mite (HDM; 31.8%). The prevalence of poorly and partially controlled asthma was higher in patients sensitized to airborne allergens (odds ratio 1.64, 95% confidence interval 1.03-2.61), in particular to HDM (odds ratio 1.73, 95% confidence interval 1.05-2.85).

CONCLUSION

Approximately 60% of elderly subjects with asthma had rhinitis, mainly allergic and often untreated, whose onset preceded asthma symptoms by a mean of approximately 10 years. Nonallergic asthma was better controlled than allergic asthma. However, HDM sensitization was greater in subjects with asthma with features resembling chronic obstructive pulmonary disease (39% vs 28%). When restricting analysis to this group, the negative role of HDM in overall asthma control (forced expiratory volume in first second and Asthma Control Test) was significant.