Temporal Variation and Factors Associated with Allergic Rhinitis in a Cohort of Rural Preschool Children from Sri Lanka.

Background: Allergic rhinitis is a common chronic childhood disease with a low diagnosis rate, causing poor quality of life, absenteeism, decreased school performance and significant healthcare cost. However, data on the prevalence of allergic rhinitis is sparse in preschoolers of rural geography, especially in developing countries.

Aim: To describe the epidemiology of allergic rhinitis in preschoolers from a rural geography of a developing country.

Methods: A population-based cross-sectional study was conducted in Anuradhapura district, Sri Lanka using the WHO-30 cluster methodology with probability proportionate to size sampling. The International Study of Asthma and Allergy in Childhood questionnaire was used to assess symptomatology.

Results: The response rate was 91.8%, with 548 (51.7%) male and 512 (48.3%) female participants. The mean age was 4.4 (± 0.7) years. Allergic rhinitis was reported in 123 (11.6%; 95% CI 9.7-13.5), and eye symptoms were reported in 41 (3.9%; 95% CI 2.8-5.2) children. Activities of daily living were disturbed due to nasal symptoms in 113 (10.7%; 95% CI 8.8-12.5). Allergic rhinitis was independently associated with severe asthma (OR 6.26; 95% CI 3.54-11.06), sleeping on the floor (OR 4.79; 95% CI 1.33-17.25) and having cats in the households (OR 1.86; 95% CI 1.18-2.91). Nasal symptoms were more common in January and August to October months. The standardized local highest monthly temperature, lowest monthly temperature, highest monthly humidity and dew point strongly predicted allergic rhinitis symptom exacerbation (F=4.8, p=0.036, adjusted R square=57.8%, VIF≤2.259, DW=2.1).

Conclusions: Allergic rhinitis affects 1 in 10 preschool children of rural Sri Lanka. The factors associated and environmental factor model developed to predict symptom exacerbation could be used to prevent allergic rhinitis exacerbations.