Diagnosis of hazelnut allergy

Allergic symptoms to hazelnut are common in adults and children. Hazelnut allergy is frequently diagnosed incorrectly, if the diagnosis is only based on hazelnut sensitization (positive skinprick and/or blood test) without clinical suspicion. Half of the children with hazelnut extract sensitization are not allergic. Recent studies indicated that new diagnostic tests, which detect IgE specific allergen may predict the severity of an allergic reaction. Sensitization to the components Cor a 9 and Cor a 14, two important hazelnut allergens, appear to be better predictor of a severe hazelnut allergy than sensitization to hazelnut extract. Using adapted cut-off levels with a high specificity results in the identification of the majority of children and almost half of the adults with a severe hazelnut allergy. These tools may reduce the number of food challenges and unnecessary elimination diets.