Patterns of atopy and allergic-respiratory outcomes in older adults

Background: While patterns of atopic sensitization are associated with allergic diseases in childhood, this has not been studied in adults previously. Aim: To identify patterns of sensitization to specific allergens and their associations with allergic-respiratory outcomes in middle-aged Australians. Methods: Data were from the Tasmanian Longitudinal Health Study (TAHS). At 53 years of age, skin prick tests to 12 common allergens (8 aeroallergens; 4 food allergens, n=2693) were performed. Latent class analysis was used to identify patterns of sensitization to specific allergens. These patterns were then associated with allergic diseases and COPD (post-BD FEV1/FVC Results: The prevalence of sensitization to aero and food allergens was 55.3% and 14.5% respectively, of which sensitization to house dust mite (HDM) was the most prevalent (41.9%). We identified five distinct patterns of sensitization: poly-sensitization (4.4%), grass pollen (25.5%), mould (2.8%), HDM sensitization (5.6%) and largely non-sensitized reference pattern (61.7%). The poly-sensitization group was associated with current asthma (OR=4.2[95%CI:2.6-6.8]), current hayfever (4.1[2.7-6.3]), current eczema (2.0[1.3-3.1]) and asthma-COPD overlap (ACO) (6.0[2.5-14.2]). The grass sensitization group showed similar but weaker associations, while the mould sensitization group was only associated with asthma and ACO. Associations were not seen for the HDM sensitization group. Conclusions: Specific patterns of sensitization are differently associated with allergic respiratory outcomes in middle age. The poly-sensitization group appears to be at highest risk.