Role of Three Different Laboratory Tests in Demonstrating Sensitization to Various Allergens in Common Atopic Disorders

Aim: To study the role of Serum total IgE, serum allergen-specific IgE and Absolute eosinophil count in demonstrating sensitization to various allergens in common atopic disorders.

Materials and Methods: A total of sixty one cases with history of atopy in the form of allergic rhinitis, asthma, and urticaria/ dermatitis were subjected to allergy profile test during a period of one year from January 2013- January 2014. The allergy profile test included serum total IgE, serum allergen specific IgE and absolute eosinophil count.

Results: In the present study more males (54%) were symptomatic than females (46%). The male to female ratio was 1.17 and overall mean age of atopic patients was 33.73±19.47. The mean age of males in the study was 29.0±20.89 and females 39.32±16.29. Total serum IgE and absolute eosinophil count was raised in 66% and 61% of cases respectively. Serum allergen specific IgE could be performed on 61% of cases and 30% of them were positive. The mean total serum IgE levels correlated well with the clinical symptoms of allergic rhinitis, asthma and dermatitis. Allergen specific IgE results revealed that people were more sensitized to inhalants (54%) than to food items (18%). Around a third of cases (27%) exhibited sensitization to both food and inhalants simultaneously. Moreover, those who were sensitized to inhalants the predominant allergen noted was dust mite (67%) followed by animal and epithelia mix (33%). No such predominance was observed in for food allergens, but subjects showed proportionate amount of sensitization to onion and garlic mix and sea food as 50% each. Further more in AllergodipR test 64% of the subjects showed very high and high grade sensitization of the class 3-4. There was 82% concordance between serum allergen specific IgE results and total serum IgE. Absolute eosinophil count is a more useful predictor of allergic rhinitis than asthma and dermatitis.

Conclusion: The findings suggest that in developing countries with increasing prevalence of atopic disorders, tests like total serum IgE, absolute eosinophil count followed by allergen-specific IgE are helpful in demonstrating sensitization to various allergens if in vivo and ex vivo tests are not possible for the clinical diagnosis.