Incidence of allergic rhinitis in a cohort of young adults from 13-15 years old to 23-25 years old in Castellon (Spain)

Background: The objective of this study was to estimate the incidence of Allergic Rhinitis (AR) in young adults and its risk or protective factors. Methods: A population-based prospective cohort study was carried out in 2012. The cohort participated in the International Study of Asthma and Allergy in Childhood in Castellon in 1994 and 2002. A telephone survey was conducted using the same questionnaires. A new case of AR was defined as the participants free of the disease in 2002, who self-reported suffering from AR or taking medications for AR in the period 2002-2012. Results: Of the 1805 schoolchildren in the cohort in 2002, 1435 young adults (23-25 years old) participated (follow-up 79.1%) in 2012; 743 were female and 692 male; their mean age was 24.9 +/- 0.6 years. Two hundred new cases of AR occurred in 1259 participants free of thedisease with an incidence of 17.3 per 1000 person-years, and the incidence increased from 2002 (RR = 1.42; 95% CI 1.15-1.75). The risk factors of AR adjusted by age and gender were sinusitis (RR= 1.77; 95% CI 1.16-2.68), atopic dermatitis (RR= 1.51; 95% CI 1.11-2.06) and constant exposure to truck traffic (RR= 1.88; 95% CI 1.12-3.17). For male participants, the risk factors were asthma, sinusitis and atopic dermatitis, and for females bronchitis was a risk factor and presence of older siblings a protective factor. Conclusions: An increase in AR incidence was observed. Sinusitis, atopic dermatitis and constant exposure to truck traffic were the risk factors of the AR with some differences by gender. (C) 2016 SEICAP. Published by Elsevier Espana, S.L.U. All rights reserved.