Atopy Is Associated with Asthma in Adults Living in Rural and Urban Southwestern Nigeria

Rationale. Factors affecting the course of asthma are not clearly understood in rural and urban communities within low-resource countries. Furthermore, the interactions between atopy, environmental exposure, and helminthic infections in modulating asthma have not been well investigated. Objectives. To conduct a feasibility study to examine the relationship between atopy and asthma in adults at two rural Health Centers and urban university college hospital in southwestern Nigeria. Methods. A convenient sample of 55 consecutive patients with stable physician-diagnosed asthma and 55 age-matched nonasthmatic controls seen at the outpatient clinics in two rural Health Centers and an urban university hospital were enrolled. All subjects underwent blood test, allergy skin test, and stool examination for ova and parasites. Wilcoxon sign-rank tests were used to compare serum eosinophilia and allergy skin test between the two groups. Results. Asthmatics in both urban and rural settings had significantly more positive skin reactions to house dust mite, cockroach, mold, and mouse epithelium than nonasthmatic controls (p < .05). Mean total serum IgE was also significantly higher in asthmatics than in nonasthmatic controls (360 vs. 90 IU/L, p < . 001). Stool parasitemia was infrequent in both groups and not statistically significant. Conclusion. Atopy is associated with adult asthma in southwest Nigeria. Larger studies to confirm the nature of this association and to examine the role of helminthic infection and other environmental factors on the expression of asthma are needed.