Study of prevalence of skin prick test positivity for food allergens in chronic urticaria patients attending a tertiary care center in South India

Abstract

Background Skin prick testing (SPT) provides information about the presence of specific immunoglobulin E (IgE) to protein and peptide antigens and maybe helpful to identify the triggering food items in chronic urticaria. Objective The aim of this study was to determine the prevalence of food allergy among chronic urticaria patients, by doing SPT with commercially available 20 food allergens. Patients and methods All consecutive patients with recurrent urticarial wheals of more than 6 weeks of duration and age more than 12 years and were included. SPT was done using 20 allergens in the study patients after detailed examination. Complete blood count and total serum IgE were checked. Results In all, 62.9 % of chronic urticaria patients had positive SPT to food allergens. No statistically significant association was found between SPT results and demographic parameters, duration of disease, urticaria activity score, or serum IgE levels. In 31.46% (28) patients who had suspected food allergy, only 7 (25%) had a positive SPT result to the corresponding allergen. Conclusion SPT s may be used as a screening test to evaluate food allergy in chronic urticaria patients. The results should better be validated with specific IgE and food challenge tests.