Astrid Versluis

Sensitization to Cor a 9 and Cor a 14 is highly specific for a hazelnut allergy with objective symptoms in Dutch children and adults

BACKGROUND Component-resolved diagnosis has been shown to improve the diagnosis of food allergy. OBJECTIVE We sought to evaluate whether component-resolved diagnosis might help to identify patients at risk of objective allergic reactions to hazelnut. METHOD A total of 161 hazelnut-sensitized patients were included: 40 children and 15 adults with objective symptoms on double-blind, placebo-controlled food challenges (DBPCFCs) and 24 adults with a convincing objective history were compared with 41 children and 41 adults with no or subjective symptoms on DBPCFCs (grouped together). IgE levels to hazelnut extract and single components were analyzed with ImmunoCAP. RESULTS IgE levels to hazelnut extract were significantly higher in children with objective than with no or subjective symptoms. In 13% of children and 49% of adults with hazelnut allergy with objective symptoms, only sensitization to rCor a 1.04 was observed and not to other water-soluble allergens. Sensitization to rCor a 8 was rare, which is in contrast to rCor a 1. Sensitization to nCor a 9, rCor a 14, or both was strongly associated with hazelnut allergy with objective symptoms. By using adapted cutoff levels, a diagnostic discrimination between severity groups was obtained. IgE levels to either nCor a 9 of 1 kUA/L or greater or rCor a 14 of 5 kUA/L or greater (children) and IgE levels to either nCor a 9 of 1 kUA/L or greater or rCor a 14 of 1 kUA/L or greater (adults) had a specificity of greater than 90% and accounted for 83% of children and 44% of adults with hazelnut allergy with objective symptoms. CONCLUSION Sensitization to Cor a 9 and Cor a 14 is highly specific for patients with objective symptoms in DBPCFCs as a marker for a more severe hazelnut allergic phenotype.

Cofactors in allergic reactions to food : physical exercise and alcohol are the most important

Involvement of cofactors, like physical exercise, alcohol consumption and use of several types of medication, are associated with more severe food allergic symptoms. However, there is limited evidence on how often cofactors play a role in food allergic reactions. The study aimed to get more insight into the frequency of exposure to cofactors and how often cofactors are associated with more severe symptoms in food allergic patients.

Potential cofactors in accidental food allergic reactions are frequently present but may not influence severity and occurrence

Cofactors, such as physical exercise and alcohol intake, might be associated with the severity or occurrence of food allergic reactions.

The influence of cofactors on allergic reactions to food

Methods A baseline questionnaire was completed by every adult patient (≥18 years) visiting the outpatients department Allergology for the first time. Patients with food allergy documented by typical allergic symptoms to food and a positive skinpricktest, ImmunoCAP or food challenge were included. Outcome measures were the reported suspected influence of the co-factors exercise, alcohol and medication on allergic complaints to food.

Unexpected allergic reactions to food, a prospective study.

Methods A prospective cohort study will be carried out from January 2012 to June 2014. A total of 250 patients with a physicianconfirmed diagnosis of food allergy will be included and followed during one year. Outcome measures are frequency, severity and causes of unexpected reactions. Participants complete an online questionnaire after every assumed accidental exposures and send in the product with food label they reacted on. The product will be analyzed to detect if the suspected allergens are present.

Sensitization to Cor a 9 and Cor a 14 is highly specific for a severe hazelnut allergy in Dutch children and adults

Background Component-resolved diagnosis has been shown to improve diagnosis of food allergy. The aim of this study was to evaluate whether component-resolved diagnosis may help to identify patients at risk of severe allergic reactions to hazelnut. Methods A total of 161 hazelnut-sensitized patients were included: 40 children and 15 adults with objective symptoms in DBPCFC and 24 adults with a convincing severe history were compared to 41 children and 41 adults with no or subjective symptoms in DBPCFC (grouped together). IgE levels to hazelnut extract and single components were analyzed with ImmunoCAP.