International variation in prevalence of rhinitis and its relation with sensitization to perennial and seasonal allergens

¹ Inst. of Epidemiology, Ulm University, Ulm, Germany
² Dept. of Epidemiology, Local Health Authority Rome /E, Rome, Italy
³ Inst. of Epidemiology, Ulm University, Ulm, Germany; Helmholtz Zentrum München German Research Center for Environmental Health, Institute of Epidemiology, 85764 Neuherberg, Germany; and Ludwig-Maximilian University Munich, Institute of Medical Data Management, Biometrics and Epidemiology (IBE) Chair of Epidemiology, 85758 Oberschleißheim, Germany
⁴ Center of Allergy and Immunology, Tbilisi, Georgia
⁵ EPAR, U707 INSERM; UMR-S 707 UPMC Paris6, Medical School St-Antoine, Paris, France
⁶ Institute of Environmental Medicine, Karolinska Institutet Stockholm, Sweden
⁷ Institute for Risk Assessment Sciences, University of Utrecht, and Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, The Netherlands
⁸ Wellcome Trust Centre for Human Genetics, University of Oxford, United Kingdom
⁹ Dr. von Haunersches University Children's Hospital, Ludwig-Maximilians-University, Munich, Germany
¹⁰ Dept. of Respiratory Physiology, Catholic University, Rome, Italy
¹¹ St. Georges's, University of London, London, United Kingdom
¹² * listed at the end of paper

^* To whom correspondence should be addressed. E-mail: gudrun.weinmayr{at}uni-ulm.de.

	Abstract

The relative importance of atopy in the etiology of rhinitis is largely unknown. We investigated geographical variations in rhinitis in relation to atopy.

The cross-sectional study involved 54,178 children (8–12 years) from 30 study centres in 22 countries worldwide. Symptoms of rhinoconjunctivitis and rhinitis without conjunctivitis in the last year were reported in parental questionnaires and children were skin prick tested.

The prevalence of rhinoconjunctivitis and rhinitis without conjunctivitis varied widely (from 1.5% to 24.5% and from 1.4% to 45.2%, respectively). For rhinoconjunctivitis, the population attributable fraction (PAF) varied from 0 to 71% for a positive prick test to one or more seasonal allergens and from 0 to 41% for perennial allergens. The PAF for sensitization to seasonal and perennial allergens was higher for affluent countries (36% and 25%, respectively) than for non-affluent countries (1.3% and 12.6%, respectively). For rhinitis without conjunctivitis, the PAF for perennial allergens was 8% for affluent countries and 4% for non-affluent countries. No significant PAF was found for seasonal allergens.

Overall, atopy explained only a limited proportion of rhinitis symptoms suggesting that the importance of other environmental factors have been underemphasized, particularly in less affluent countries. Atopy seems to be only marginally relevant for rhinitis without conjunctivitis, which seems mainly to reflect non-atopic rhinitis.