Natural course of pollen-induced allergic rhinitis from childhood to
adulthood: a 20-year follow-up
Abstract
Background Allergic rhinitis (AR) is one of the most common
chronic diseases worldwide. There are limited prospective long-term data
regarding persistency and remission of AR. The objective of this study
was to investigate the natural course of pollen-induced AR (pollen-AR)
over 20 years, from childhood into early adulthood. Methods
Data from 1137 subjects in the Barn/Children Allergi/Allergy Milieu
Stockholm Epidemiologic birth cohort (BAMSE) with a completed
questionnaire regarding symptoms, asthma, treatment with allergen
immunotherapy (AIT) and results of allergen-specific IgE for inhalant
allergens at 4, 8, 16 and 24 years were analysed. Pollen-AR was defined
as sneezing, runny, itchy, or blocked nose; and itchy or watery eyes
when exposed to birch and/or grass pollen in combination with
allergen-specific IgE ≥0.35kU A/l to birch and/or grass.
Results Approximately 75% of children with pollen-AR at 4 or 8
years had persistent disease up to 24 years, and 30% developed asthma.
The probability of persistency was high already at low levels of
pollen-specific IgE. The highest rate of remission from pollen-AR was
seen between 16 and 24 years (21.5%), however the majority remained
sensitized. This period was also when pollen-specific IgE-levels stopped
increasing and the average estimated annual incidence of pollen-AR
decreased from 1.5% to 0.8% per year. Conclusion Children
with pollen-AR are at high risk of persistent disease for at least 20
years. Childhood up to adolescence seems to be the most dynamic period
of AR progression. Our findings underline the close cross-sectional and
longitudinal relationship between sensitization, AR, and asthma.