MOH Holdings Pte Ltd (MOHH)1, Singapore General Hospital2
In Singapore, food is a common perceived trigger for atopic dermatitis (AD). Presentations of food allergy (FA) range from IgE-mediated reactions such as urticaria, angioedema to delayed-Tcell-mediated reactions with eczema flares. FA varies with age. Existing workup for FA is not standardized, with delayed reactions missed with IgE or skin prick testing (SPT). We aim to explore the type of FA and modalities available in the evaluation of adult AD patients.
11 adult patients (3 Male,8 Female) aged 26-47years with AD (as per Hannifin-Rajka criteria) were recruited. All kept food diaries. Blood was taken for IgE and specific-IgE to a panel of food allergens. SPTs and food APTs were performed. All were longitudinally followed up over 16-20months, with specific food elimination diet based on food diary and investigation findings.
The most common food allergen reported was seafood: shrimp(n=8,73%), lobster(n=8,73%), crab(n=7,64%), clam(n=6,55%), and oyster(n=5,46%). The symptoms observed varied from pruritus (n=10,91%), wheals (n=5,46%), flushing (n=5,46%) to eczema flares(n=6,55%). All had elevated total IgE levels. Correlation of clinical symptoms with raised food-specific-IgE were seen with shrimp (n=3/8,38%), lobster(n= 2/7,29%) and crab(n=1,15%). Clinical correlation with positive SPTs were noted with oyster(n=1,17%) and crab(n=1,17%). Correlation across 3 modalities (specific-IgE, SPT, APT) was seen in 1 patient. All reported clinical improvement after an elimination diet.
In our small pilot study, seafood crustaceans were the commonest food allergen. The utility of food APT was not found to be beneficial. FA evaluation still requires correlation with clinical history, specific-IgE, SPT, elimination diet and/or an oral food challenge.