Major increase in allergic sensitization in schoolchildren from 1996 to 2006 in northern Sweden

Abstract

Background Time trends for allergic sensitization are poorly known. Aim To compare the trends in prevalence of allergic sensitization and associated risk factors in children. Methods Two cohorts of children (age 7–8 years) were invited to skin prick testing (SPT) ten years apart, 1996 and 2006. Participation rate was 2148 (88%) and 1700 (90%), respectively. The methods were identical and ten common airborne allergens were used. An expanded ISAAC-questionnaire about symptoms and possible risk factors for allergic conditions was completed by the parents. Results The prevalence of any positive SPT increased from 21% in 1996 to 30% in 2006 (p<0.001). The pattern of sensitization remained similar, and sensitization to cat was most common both years, 13% and 19%, respectively. Sensitization to mites and mould were uncommon in both surveys. A family history of allergy was a significant risk factor for a positive SPT both years (OR 1.7). Factors that in 1996 had a protective effect, i.e. rural living and having several siblings, had lost this effect in 2006. The prevalence of most risk factors remained similar, but respiratory infections and smoking among parents decreased significantly. During the same period there was no significant increase in prevalence of current wheeze (11.9% to 12.4%, n.s.) or symptoms of rhinitis or eczema. Conclusion The prevalence of allergic sensitization increased significantly from 1996 to 2006, while no increase in clinical symptoms was found. The parallel decrease in parental smoking and respiratory infections indicate a different influence of environmental factors on allergic sensitization and clinical symptoms, respectively.

Asthma in adolescence affects daily life and school attendance - Two cross-sectional population-based studies 10 years apart

“…The questionnaire was expanded with additional questions about symptoms, use of medications and physician diagnoses as well as possible risk factors including school environment and physical activity (Rönmark et al., 2009). In 2003, the adolescents also answered an open question: ‘If your asthma gets worse, what in the school setting do you think is causing the deterioration?’…”

MACC regional multi-model ensemble simulations of birch pollen dispersion in Europe

“…According to the European Federation of Allergy and Airway Diseases Patients Associations, 80 million (24.4 %) adults living in Europe are allergic. The allergy prevalence in children is 30-40 % and increasing (Laatikainen et al, 2011;Rönmark et al, 2009). Allergy to various types of pollen in the air, exacerbated by co-exposure to chemical pollutants and fine aerosols, is the number one chronic disease in Europe, overshadowing allergy to house dust mite and affecting over 20 % of the population (Bousquet et al, 2007).…”

Release of Bet v 1 from birch pollen from 5 European countries. Results from the HIALINE study

“…Allergic diseases to airborne allergens have been steadily increasing over the past decades (Eder et al, 2006). This increase in prevalence is also due to replacement of older less sensitized individuals in the population by younger individuals with a higher degree of sensitization (Jarvis et al, 2005;Rönmark et al, 2009;Laatikainen et al, 2011). For developed countries a leveling-off of allergic disease prevalence was reported (Asher et al, 2006;Grize et al, 2006), but for some highly developed countries like Finland an end of this epidemic is not in sight (Laatikainen et al, 2011).…”