Association of Chronic Urticaria and Foods by Using a Food Questionnaire

Abstract

Background: Many patients with chronic urticaria (CU) have suspected foods as eliciting factors and have eliminated these diets. However, there have been few studies of the relationship between CU and food intolerance in Korea. Objective: We sought to evaluate the causal relationship between CU and food intolerance by the questionnaire method, which was compared according to aspirin sensitivity. Method: A total of 235 patients diagnosed as having CU were enrolled and classified into the 2 groups: according to histories and the oral aspirin, challenge test results aspirin intolerant chronic urticaria (AICU) and aspirin tolerant chronic urticaria (ATCU). The questionnaires were used to investigate the presence of foods eliciting urticaria. The urticaria severity score and the visual analogue scale for urticaria were measured. Food hypersensitivity was determined by skin prick tests. Serum total eosinophil counts, the total IgE level anti-nuclear antibody and antithyroid autoantibody were measured. Result: Of the 235 patients with CU, 119 (50.6%) answered that their symptoms were aggravated by food, in which the causative common foods were fish (45.4%), seafood (44.5%), meat (43.7%) and instant food (33.6%) in a decreasing order of frequency. There was no significant difference in the frequency of food intolerance between AICU and ATCU patients. However a significant association was noted with vegetable in AICU patients (6.2% for AICU patients vs. 2.1% for ATCU patients, P=0.025), while a significant association was noted with instant food in ATCU patients (14.7% for ATCU patients vs. 16.9% for AICU patients, P=0.008). CU patients with food intolerance, especially AICU patients, tended to have higher symptom scores, atopy rates and prevalences of allergic diseases than those without. Among 138 patients who underwent skin prick tests, only 47 (34.1%) showed positive responses to suspected food allergens. Conclusion: It is suggested that more than 50% of CU patients may have a possible association between foods and their symptoms. Careful history taking is needed for proper management of CU patients, especially AICU patients with associated allergic diseases or atopy.