Allergy in Botswana

Introduction. Unlike South Africa and Zimbabwe, allergen sensitisation patterns are unknown for Botswana. Skin-prick test (SPT) results for Gaborone are reviewed. Methods: SPTs from an allergy practice included trees, grasses, weeds, moulds, cat, dog, dust mites and cockroach. Food SPTs were conducted when clinically indicated. Results: In 126 patients, median age was 7.8 years (interquartile range (IQR) 3.4-16.3 years), with male predominance (56%); 68% were atopic - 72% were sensitised to aeroallergens, 15% foods and 13% both. Top aeroallergen sensitisations were: Bermuda grass (41%), Timothy grass (33%), maize pollen (32%), Alternaria (28%), English plantain (25%) and acacia tree (21%). Less common were: dust mite (14%), pets (14%), and cockroach (10%). Peanut and egg allergy were common food allergies (10%). Novel food allergies included mopane worm and mogwagwa. Frequent clinical presentations were rhinitis (70%), asthma (42%) and eczema (30%). Rhinitis patients were significantly grass allergic (Bermuda p<0.01, Timothy p=0.04, maize pollen p<0.01). Asthmatics were more likely to be cockroach (p=0.02) or Aspergillus (p<0.01) allergic. Conjunctivitis was significantly linked to Bermuda grass (p<0.001), maize (p<0.01) and acacia tree pollen (p=0.02) allergy. Conclusion: Bermuda grass allergy is common in Botswana, but dust mite sensitisation is infrequent. Peanut and egg were the most common food allergies. Novel food allergens were identified.