Prevalence of indoor-allergen sensitivity among asthmatic children aged 5-17 years in Nairobi

Abstract

Objectives: Atopic sensitization is important in childhood asthma, however data regarding allergen sensitization patterns in Kenya is unavailable. We sought to determine the prevalence and spectrum of inhalant allergen sensitivity among asthmatic children aged 5-17 years in Nairobi.
Methodology: This was a cross sectional study conducted in paediatric outpatient and asthma clinics of two public hospitals in Nairobi, Kenya. An adapted International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire was administered, followed by skin prick testing for house dust mite, cat, dog, cockroach and mould.
Results: Of the 92 children recruited, 71% had aeroallergen sensitization, with 38% having single allergen sensitization, 27.2% sensitized to two and 6.5 % to three allergens. The most prevalent allergen sensitization was Dust mite (58.7%) followed by indoor mould (37%), dog (15.2%), cockroach (12%) and least cat (5.4%). Dust-mite sensitization was significantly associated with asthma and each of the other associated allergic conditions. Allergic rhinitis was present in 48.9%, eczema in 31.5% and ocular allergy in 16.3% of the participants. Odds of a positive skin prick test increased with asthma-allergic rhinitis co-morbidity OR= 2.2 [(95% CI 0.8,5.8), p=0.08]
Conclusion: There is a high prevalence of allergic sensitization among asthmatic children in Nairobi with dust mite followed by mould as the commonest causes. Co-morbidity with asthma and allergic rhinitis was associated with the highest prevalence of allergic sensitization. In a resource constrained setting, asthmatic children with co-existing allergic rhinitis should be prioritized for aeroallergen sensitivity testing.