TABLE VI.B-2.
Evidence for the effects of pollen allergen exposure (in utero and early childhood exposure) on the development of allergic rhinitis
Study | Year | LOE | Study design | Study groups | Type of exposure | Conclusionb |
---|---|---|---|---|---|---|
Erbas et al.481 | 2013 | 2b | Prospective birth cohort | 620 children (6–7 years old) from MACS RCT (with at least 1 first-degree family member with a history of eczema, asthma, hay fever, severe food allergy) | Pollen exposurea during infancy (at 3–6 months) | Risk factor for hay fever (OR 1.1; 95% CI, 1.01–1.3) |
Kihlström et al.519 | 2002 | 3b | Cross-sectional | 583 children with atopic heredity (4–5 years old) | High-dose exposure to birch pollen at 0–3 months | No association with allergic rhinoconjunctivitis (OR 1.0; 95% CI, 0.6–1.8) |
High-dose exposure to birch pollen at 1 year | No association with allergic rhinoconjunctivitis (OR 1.3; 95% CI, 0.8–2.2) |
Defined as birth “inside” or “outside” the pollen season and by measuring daily 24-hour average pollen concentrations for grass and others (which include trees, weeds, and herbs).
ORs are adjusted and reported with 95% CIs in parentheses.
CI = confidence interval; LOE = level of evidence; MACS = Melbourne Atopy Cohort Study; OR = odds ratio; RCT = randomized controlled trial.