Allergic disease and Staphylococcus aureus carriage in adolescents in the Arctic region of Norway.

Background: Allergic diseases are common chronic diseases in children and adolescents, but limited epidemiological data are available during transition into adulthood. Nasal Staphylococcus aureus carriage has been linked to increased prevalence of allergic disease. The objective of this study was to define the prevalence of allergic diseases in adolescents above the Arctic Circle in Northern Norway and to study the associations of S. aureus carriage with allergic diseases.

Methods: A school-based cohort in late adolescence (18-19 years) was invited to participate in a cross-sectional study on lifestyle and health, and 868 attended (71.9%). Self-reported allergic disease and severity of eczema were assessed by Mechanisms of the Development of Allergy and Patient-Oriented Eczema Measure questionnaires. Participants were tested with spirometry and exhaled nitric oxide (FeNO) and swabbed for bacterial culture from nose and eczematous skin.

Results: We found asthma, eczema, allergic rhinitis (AR), and nasal S. aureus carriage among 11.9%, 10.4%, 26.0%, and 51.3% of the participants, respectively, and 10.2% had allergic multimorbidity. Lifetime prevalence for any allergic disease was 45.1%. Reduced lung function and increased FeNO were found in 11.6% and 22.1% in participants with asthma, respectively. Nasal S. aureus carriage was associated with eczema, severe asthma, and severe AR. FeNO > 25 ppb was associated with both asthma and nasal S. aureus carriage.

Conclusion: Asthma, eczema, and AR are common among adolescents above the Arctic Circle in Norway. Allergic disease is associated with S. aureus carriage, but its role in the pathogenesis and severity is not established.