A Study of Food Allergy in Patients with Urticaria

Kang, Kweon Soo; Han, Hee Jin; Lee, Joung Ok; Park, Chun Wook; Lee, Cheol Heon

Abstract

BACKGROUND
Although urticaria is a common skin reaction pattern occuring at some time in the life of approximately 15% to 20% of the population, the exact prevalence of food-induced acute or chronic urticaria remains unknown. OBJECT: The purpose of this study was to determine the prevalence of specific food allergies in patients with urticaria and the potential utility of the skin prick test and CAP-RAST FEIA in the diagnosis of food allergy. METHODS: One hundred patients with urticaria were evaluated for food hypersensitivity by history, eosinophil count, IgE, skin prick test, CAP-RAST FEIA, and open food challenge test (OFCT). RESULTS: 1) The prevalence of specific food allergies in the study population was 35% in history and 8, 18 and 6% in prick, CAP-RAST FEIA and OFCT, respectively. 2) The frequent food allergens were milk, egg, peanut, and wheat. 3) There were no correlations between the duration of urticaria and prick test, CAP-RAST FEIA and OFCT results. 4) Serum IgE levels were correlated with the prick test and CAP-RAST FEIA results, but not the OFCT results. 5) According to the history, 35 patients with urticaria answered that their symptoms were related to food, and of the 35 patients, positive reactions to the prick test and CAP-RAST FEIA were observed in 6 and 10 patients, respectively. Among the other 65 patients who answered that there was no relation between urticaria and food, 2 patients reacted positively to the prick test and 8 patients showed positive result to CAP-RAST FEIA. CONCLUSION: In contrast to high prevalence of food history, the prevalence of food-induced allergic urticaria in Korean patients is only 6%. In contrast to the prick test, CAP-RAST FEIA provides a standardized measurement of food specific IgE antibodies, which may be more useful diagnostic test than prick test to diagnose food allergy in urticaria.