High prevalence of allergic diseases and sensitization in a low allergen country.
BACKGROUND
The prevalence of adult atopic diseases in Iceland is lower than in other West European countries, despite an affluent lifestyle, but limited data are available on children. The main aim of this study was to investigate the prevalence of atopic diseases and sensitivity to common allergens in 10- to 11-year-old Icelandic schoolchildren as part of phase II of the International Study of Asthma and Allergies in Children (ISAAC).


METHODS
Nine hundred and forty-six children and their parents answered a questionnaire about atopic diseases. Skin prick tests with six allergens were performed on 773 children and they were examined for signs of atopic dermatitis (AD).


RESULTS
The 12-month prevalence of allergic rhinoconjunctivitis and asthma was 11.5% and 8.9% respectively. The reported prevalence of AD was 27%, but only 9.2% had signs when inspected. A positive skin prick test (SPT) was found in 24.4% of the children, that is 18.8% to grass, 12.9% to cat, 3.6% to trees, 3.0% to Dermatophagoides pteronyssinus, 1.4% to D. farinae and 0.5% to Alternaria.


CONCLUSIONS
The high prevalence of atopic diseases in children at 10-11 years is surprising, as the prevalence in adults is low in Iceland. The findings resemble those in developing countries. Iceland has had an affluent lifestyle for a considerable time, but the absence of dust mites, low pet ownership and relatively low pollen counts in the country raise doubts about the role of exposure levels in the development of sensitization and atopic diseases.
Clausen
Michael
M
Children's Hospital Iceland, Landspitali-University Hospital, Reykjavik, Iceland. mc@landspitali.is
Kristjansson
Sigurdur
S
Haraldsson
Asgeir
A
Björkstén
Bengt
B
D016902:Air Pollution, Indoor / Q000009:adverse effects; D000485:Allergens / Q000276:immunology*; D000818:Animals; D000829:Animals, Domestic; D002648:Child; D003430:Cross-Sectional Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000235:genetics / Q000276:immunology; D007055:Iceland / Q000453:epidemiology; D007114:Immunization; D015995:Prevalence; D012307:Risk Factors; D012882:Skin Tests; D011795:Surveys and Questionnaires; D014028:Tobacco Smoke Pollution / Q000009:adverse effects
D000485:Allergens; D014028:Tobacco Smoke Pollution