Background: Allergic diseases, including atopic dermatitis (AD), are increasingly becoming a clinical problem in developing countries.
Objective: We investigated the prevalence of AD symptoms and the effects of potential environmental aetiologies in rural and urban areas of Jimma in southwestern Ethiopia.
Methods: Information on allergic disease symptoms and lifestyle factors was gathered in an interviewer-led cross-sectional questionnaire-based population survey of 9844 urban and 3032 rural participants of all ages. A one-in-four subsample underwent skin prick testing for hypersensitivity to Dermatophagoides pteronyssinus, mixed threshings, and aspergillus.
Results: Around 95% of those eligible took part in the survey. Lifetime cumulative prevalence of AD symptoms was generally low with an overall prevalence of 1.2%, but was higher in the urban (1.5%) than in the rural area (0.3%; odds ratio (OR)=4.45 [95% CI 2.34-8.47]). AD symptoms were strongly associated with wheeze (adjusted OR=22.03 [15.45-31.42]) and rhinitis symptoms (61.94 [42.66-89.95]). Of several environmental exposures assessed, residence in a house made of brick (rather than mud) walls with wooden (rather than clay) floor, exposure to cigarette smoke as a child, having lived outside of Jimma in the past, and being of the Tigrean ethnic group were associated with an increased risk of AD symptoms.
Conclusion: Although the overall prevalence of AD symptoms was low in this Ethiopian population, a marked urban-rural gradient was evident. Lifestyle factors linked to urbanization were associated with an increased risk of AD symptoms.