Abstract
Background: Allergic sensitisation is a major risk factor for asthma in adults. In Sweden, pollens and furry animals are the main sensitisers, while mites play a minor role and often exists as co-sensitisation.
Aim: To study risk factors for mite sensitisation in Swedish adults.
Methods: Out of 18072 participants in the West Sweden Asthma Study, a random sample of 1472 aged 16-60 y were invited to skin prick testing (SPT) 2009-2012. SPTs covered 11 aeroallergens, including the mites D. pteronyssinus and D. farinae. Complete SPTs were performed in 788 subjects (58% women).
Results: The prevalence of any mite sensitisation was 12.6%, 11.3% to D. pteronyssinus and 9.6% to D. farinae. Physician-diagnosed asthma was seen in 12.1% and current wheeze in 23.6%. Sensitisation to pollens, animals and mites showed similar risk factor patterns, however mite sensitisation was also associated with work exposure to gas, dust and fumes (GDF), OR 2.0 (1.2-3.3) and low birth weight (<2500g, LBW) OR 1.9 (1.1- 3.5), adjusted for sex, age, parental allergy, smoking and keeping livestock. This was not seen for pollens or animals, ORs 0.8, (N.S.). The effect of GDF was strongest in age 31-45, interaction p=0.039. GDF was associated with wheeze and asthma only in mite sensitised subjects, OR 4.2 (1.8-9.9) and OR 4.6 (2.0-10.5).
Discussion: In this random sample of Swedish adults GDF and LBW were associated with sensitisation to mites, but not pollens or animals. GDF-associated respiratory epithelial damage and/or immunomodulatory mechanisms may contribute to mite sensitisation. The data suggest that the known association of GDF with respiratory symptoms occurs predominantly in mite-sensitised subjects.
- © 2014 ERS