Chapter Nut Allergens
Among 383 patients with food allergy, 37% revealed positive reaction to hazelnut (Etesamifar and Wüthrich 1998), and among pollen-allergic patients as much as 53% (Eriksson et al. 1982). In the areas where birch trees are endemic, hazelnut allergy is most often manifested as mild OAS, both in children and in adults (Cudowska and Kaczmarski 2004). However, the route of clinically relevant sensitization to hazelnut in children can be nonpollen related (Flinterman et al. 2006). Children can be sensitized to hazelnut at an early age. In many cases, reactions are very serious and frequently correlated with sensitivity to peanut or other tree nuts (Pumphrey et al. 1999). So far it has not been univocally settled which major allergens, and of which kind of nut, are responsible for the primary sensitization in children with objective reactions to hazelnuts.