Early clinical predictors of childhood food allergy

Abstract

Food allergy is an increasingly prevalent disease in children in Hong Kong. Current diagnostic and management practices rely heavily on western literature. However, we believe the unique genetic and environmental interplay in the population renders it necessary to generate our own local data to understand the local epidemiology and validate current practices.

We performed a retrospective chart review on patients <18 years old with a clinical diagnosis of food allergy referred to a teaching hospital affiliated Allergy Clinic fromSep2008toAug2013. We summarized the demographics, clinical symptoms and co-morbidities, family history and investigation results (SPT, serum-specific IgE and/or food challenge) and investigated their relationship with clinical severity and resolution. 491 patients were referred for food allergen testing. The clinical profiles for 449 (91.4%) patients with complete data were available for analysis. The primary indications for testing were suspected immediate hypersensitivity to food, moderate to severe eczema with suspected food as triggers, and multiple atopy manifestations with suspected food as triggers. Two hundred eighteen patients (218/379; 57.5%) were sensitized to at least one food item. Among these, 92 were diagnosed of peanut allergy by fulfilling 1) positive food challenge or 2) 95% specific laboratory test cut-off values (SPT >=8mm negative control, food specific IgE to peanut >=15 KUa/L or food specific component-resolved diagnostics Ara h2 >=1 KUa/L) or 3) sensitization (SPT >=3mm) plus convincing clinical history. Comparing to Non-Peanut Allergy patients, Children with Peanut Allergy are more likely to be male, have infantile eczema, and have positive family history of atopy. They are also more likely to suffer from multiple food sensitizations, have more severe symptoms, and are less likely to resolve.

Peanut allergy is not uncommonly seen in Hong Kong children at a tertiary setting. Due to its severity and persistence, it deserves detailed longitudinal follow up to understand its natural history in local setting with due considerations to Asian infant feeding practice, health care model, culinary, diet, cultural and socioeconomic perspectives.