The prevalence of skin-test-positive allergic rhinitis in Danish adults: two cross-sectional surveys 8 years apart. The Copenhagen Allergy Study.
BACKGROUND
It is disputed whether increases in self-reported respiratory allergy represent a true increase or merely increased recognition. We aimed to investigate whether the prevalence of skin-prick-test (SPT)-positive allergic rhinitis had increased in an adult general population in Copenhagen, Denmark.


METHODS
Two cross-sectional surveys were carried out in 1990 and 1998. A screening questionnaire on respiratory symptoms in random samples of 15-41-year-olds preceded both surveys. Among the responders, random samples were invited to a health examination including SPT. Totals of 312 (participation rate 74.6%) and 482 (participation rate 53.4%) subjects were examined in 1990 and 1998, respectively. Diagnoses of SPT-positive allergic rhinitis were based on a history of nasal symptoms on exposure to allergens and SPT positivity to allergens.


RESULTS
The prevalence of a diagnosis of SPT-positive allergic rhinitis increased from 12.9% to 22.5% (adjusted odds ratio 1.94, 95% CI 1.30-2.90), whereas the prevalence of a positive SPT (allergen histamine wheal ratio > or = 0.5) to one or more of 10 allergens increased from 27.7% to 33.9% (adjusted odds ratio 1.47, 95% CI 1.05-2.05).


CONCLUSIONS
The prevalence of SPT-positive allergic rhinitis has increased significantly. Our findings indicate that a true increase in respiratory allergy has occurred.
Linneberg
A
A
Centre of Preventive Medicine, Department of Internal Medicine M, Glostrup Hospital, University of Copenhagen, Denmark.
Jørgensen
T
T
Nielsen
N H
NH
Madsen
F
F
Frølund
L
L
Dirksen
A
A
D000328:Adult; D000485:Allergens; D003430:Cross-Sectional Studies; D003718:Denmark / Q000453:epidemiology; D006801:Humans; D015995:Prevalence; D012221:Rhinitis, Allergic, Perennial / Q000175:diagnosis / Q000453:epidemiology*; D012882:Skin Tests; D011795:Surveys and Questionnaires
D000485:Allergens