An analysis of skin prick test reactions in asthmatics in a hot climate and desert environment.

Background: Studies have shown that allergens are very important sensitizing agents in patients with asthma. Respiratory disorders such as asthma and allergic rhinitis are common in the United Arab Emirates, (UAE).

Objectives: The aim of this study was to investigate the relationship between allergen specific IgE antibodies and skin test reactivity in patients with asthma in hot climate and desert Arabian country.

Design: A hospital-based prospective study conducted.

Setting: Tawam Teaching Hospital, Al-Ain, UAE.

Patients: 327 adult patients recruited with respiratory, dermatologic and ophthalmologic diseases of suspected allergic origin who attended Tawam Teaching Hospital of Faculty of Medicine, Al Ain, UAE, during three years from 1996 to 1998.

Methods: Skin Prick Test (SPT) and radioallegosorbent tests (RAST) were performed on 327 patients for common allergens. The blood sample was taken for measuring specific IgE concentration.

Results: There were 327 UAE patients of whom 117 (35.8%) were males and 210 (64.2%) were females. The population sample had a higher prevalence of diagnosed asthma among females (48.1%) than in males (36.7%). Skin prick testing showed that 244 patients (74.6%) had positive results, and 83 patients (25.4%) were found to be skin test negative. 44% had a positive family history of asthma. The twelve most common reactions in the United Arab Emirates were: Mesquite (45.5%), Grass Mix (40.7%). Cottonwood (33.1%), Bermuda Grass (31.3%), Kochi (25.8%), Acacia (25.6%), Alfalfa (22.9%), Chenopodium (19.6%), Date palm (13.8%), Cockroach (14.7%), house dust (11.9) and Dust mite (9.5%). Total IgE level (> 100 kU/l) was strongly associated with history of wheeze (p = 0.019), asthma (p = 0.01) and allergic rhinitis (p < 0.0001), atopy (p < 0.0001) and the presence of specific IgE antibodies to grass pollen (p < 0.0001), mite (p = 0.008) and cockroaches (p = 0.025).

Conclusion: The present study revealed that hypersensitivity to pollens, house dust, dust mite and cockroach was common. The family history, environment, and airborne allergens are identified to be risk factors for asthma and other allergic diseases in Arabian Gulf Countries.