Food hypersensitivity in patients with childhood atopic dermatitis in Korea.

Background: It is well known that atopic dermatitis (AD) is related to food hypersensitivity, although its prevalence varies among several studies according to age group, severity, country, survey time, and test method.

Objective: To examine the prevalence and status of food hypersensitivity among childhood AD patients in Korea.

Methods: A total of 95 patients were enrolled in the study. The history of food hypersensitivity was collected by interviews. The severity of AD was evaluated by eczema area and severity index (EASI). We took blood samples to measure serum total and food-specific immunoglobulin E (IgE) levels. Based on the histories and serum IgE levels, open oral food challenge (OFC) testing was performed to confirm food hypersensitivity.

Results: Forty-two (44.2%) of the 95 AD patients had histories of food hypersensitivity. They reported that the most common suspicious foods were egg (n=13, 13.7%), pork (n=9, 9.5%) and cow milk (n=8, 8.4%). The mean EASI score was 16.05±9.76. Thirty-nine (41.1%) of the 95 patients showed elevated serum food-specific IgE levels. The specific IgE levels were elevated for egg (n=17, 17.9%), milk (n=12, 12.6%), peanut (n=10, 10.5%) and wheat (n=8, 8.4%). Fifty-one (53.8%) of 95 patients underwent open OFC, and only 7 (13.7%) of these patients showed positive reactions.

Conclusion: The overall prevalence of food hypersensitivity in patients with childhood AD in Korea was 8.3% (7/84). The most common foods causing food hypersensitivity were egg and milk. Among the foods causing hypersensitivity, AD patients in Korea often underestimated peanut, while they overestimated pork.