MHK Ho, KPP Aung, WHS Wong, EYT Chan, TL Lee, CY Chong, WC Chow, PPW Lee, YL Lau

Abstract

Background: Despite an increasing body of clinical and laboratory evidence suggesting that food hypersensitivity plays a pathogenic role in Atopic Eczema (AE) in a subset of patients, whether IgE food sensitization has any impact on the clinical severity of AE is not clearly established. Objective: To investigate the association between the severity of eczema and immunoglobulin E mediated food sensitization among atopic eczema children in Hong Kong. Study Design: A retrospective chart review study of total 77 atopic eczema cases (age 0-14 years) was carried out. The eczema severity scores (three item severity scores TIS), skin prick test results (wheal diameters), and food specific immunoglobulin E levels, clinician diagnosed food allergy were recorded as main outcome measures. Immunoglobulin E mediated food sensitization was diagnosed when the skin prick test resulted in a wheal diameter of greater than 3 mm compared with the negative control and serum food specific immunoglobulin E level greater than 0.35 ku/L. Result: Overall IgE food sensitization to at least 1 food by either skin prick test or blood test was 81.8%. Eczema severity by TIS was not correlated with the frequency of immunoglobulin E mediated food sensitizations (p-value=0.1346). More than 60% of children in this study developed eczema before 6 months old and this early onset eczema group was highly associated with egg, cow's milk and fish sensitizations (p-value=0.0179, 0.015, and 0.0468 respectively). A positive association was found between the eczema severity and serum total IgE level (p-value=0.002). Conclusion: IgE food sensitization is very common in this small cohort of Hong Kong children with atopic eczema. Most eczema children with or without clinical history of food reactions have shown positive SPT and CAP-FEIA, or one of the two. Severity of atopic eczema is positively associated with the levels of total IgE. It was not shown that any particular food sensitization was associated with severity of eczema.

背景：儘管越來越多的臨床和實驗室證據，表明食物過敏反應在過敏性濕疹患者的發病中發揮作用，但IgE食物致敏對過敏性濕疹患者的臨床嚴重程度是否有影響尚不明確。目標：調查研究香港過敏性濕疹的兒童中濕疹的嚴重程度與IgE介導的食物過敏之間的關聯。研究設計：回顧性圖表分析77例過敏性濕疹病例（年齡0-14歲）。記錄濕疹嚴重程度評分（三項嚴重性評分TIS）、皮膚點刺試驗結果（水泡直徑）和食品特定IgE水平、臨床醫師診斷為食物過敏，作為主要衡量結局的標準。皮膚點刺試驗結果水泡直徑較陰性對照組大於3毫米，血清食物特定免疫球蛋白 E 水平高於 0.35 ku/L，則診斷為IgE 介導的食品過敏。結果：通過皮膚點刺試驗或血液測試至少對 1種IgE食物過敏的總量為81.8%。TIS判斷的濕疹嚴重性與免疫球蛋白 E 介導的食品過敏發生頻率無相關（p 值 = 0.1346）。在這項研究中超過 60%的兒童在 6個月大以前就出現濕疹，而且這些早期發病的病人與雞蛋、牛奶和魚過敏高度相關（p 值 = 0.0179、0.015 和 0.0468 分別）。濕疹嚴重程度與血清總 IgE 水平呈正相關（p值 = 0.002）。結論：IgE食物致敏在這小組香港過敏性濕疹兒童中很常見。大多數濕疹兒童無論有無食物反應的臨床史，均顯示出明確的SPT和CAP-FEIA，或兩者之一。過敏性濕疹的嚴重性與總IgE水平呈正相關。但未顯示某種特定食物過敏與濕疹的嚴重程度相關。