ASTHMA, TYPE-1 ALLERGY AND RELATED CONDITIONS IN 7-YEAR-OLD AND 8-YEAR-OLD CHILDREN IN NORTHERN SWEDEN - PREVALENCE RATES AND RISK FACTOR PATTERN

As a first step in an intervention study of asthma and allergic diseas es among school children, a cross-sectional study was performed during Winter 1996 in three towns (Kiruna, Lulea and Pitea) in the northernm ost province of Sweden, Norrbotten. The cross-sectional study aimed to measure the prevalence of asthma, type-1 allergy and allergic disease s in order to make it possible to measure the incidence of the disease s, conditions and symptoms related to the diseases. Another aim was to perform a screening for possible risk factors, All children enrolled in the first and second classes at school, 7 and 8 years old, were inv ited to take part in this study, The ISAAC questionnaire with added qu estions about symptoms, morbidity, heredity and environment was distri buted by the schools to the parents. The response rate was 97%, and 34 31 completed questionnaires were returned. The children in two of the municipalities were also invited to skin test. and 2149 (88%) were tes ted with 10 common airborne allergens. The results showed that 7% of t he children were currently using or had used asthma medicines during t he last 12 months, Six percent had asthma diagnosed by a physician, an d 4% were using inhaled corticosteroids. The prevalence of wheezing du ring the last 12 months was 12%, rhinitis without colds 14%, and eczem a 27%, while 21% had a positive skin test. The respiratory symptoms an d conditions were significantly greater in boys and, further, they wer e most prevalent in Kiruna in the very north, though not significantly . Type-1 allergy and asthma had different risk factor patterns. The ma in risk factors for asthma were a Family history of asthma (OR=3.2) fo llowed by past or present house dampness (OR=1.9), male sex (OR=1.7) a nd a smoking mother (OR=1.6). In Kiruna, when none of these three risk factors were present, none of the children had asthma, but when all t hree were present, 38% of these children were using asthma medicines.