Allergic risk factors for severe asthma among preschool children: a descriptive-analytical study from rural Sri Lanka

Introduction: The role of household and food allergens in disease progression of severe asthma (SA) in preschool children from rural geographies is poorly understood. This study aimed to assess allergic factors of the domestic environment and the diet on SA. Methods: A descriptive-analytical study was conducted in Anuradhapura district, Sri Lanka at 36 preschools selected by multistage cluster sampling. SA symptomatology was assessed with the validated International Study of Asthma & Allergy in Childhood questionnaire. Results: The study sample consisted of 548 male and 512 female children with a mean age of 4.4 (±0.7) years. Symptoms of SA were reported in 76 (7.2%:95%CI 5.7-8.8) preschoolers. Living in a house with a clay floor increased the risk of SA (p=0.01, unadjusted OR 3.7:95%CI 1.6-8.9) while having a cement floor was an independent protective factor (OR 0.4:95%CI 0.2-0.8). Exposure to passive smoking (OR 1.6:95%CI 0.9-2.9) and allergens of domestic dogs (OR 2.3:95%CI 1.0-5.2) was independently associated with SA. Frequent consumption of food with high histamine content (Skipjack tuna) was an independent risk factor (OR 2.0: 95%CI 1.2-3.4) and frequent consumption of antioxidant-rich ridge gourd (Luffa acutangula) was a protective factor (p=0.04, unadjusted OR 0.5:95%CI 0.3-0.9). Frequent consumption of antioxidant-rich lady’s fingers (Abelmoschus esculentus) (p=0.03, unadjusted OR 0.7:95%CI 0.6-0.9) and Pennywort (Centella asiatica) (p=0.01, unadjusted OR 0.7:95%CI 0.5-0.9) was protective against developing dry cough at night in asthmatics. Conclusion: Allergic factors of both the domestic environment and the diet increased the likelihood of SA among preschoolers.