Hazelnut allergy: from pollen-associated mild allergy to severe anaphylactic reactions.
OBJECTIVE
Hazelnut allergy can vary between mild oral symptoms and potentially dangerous anaphylaxis. There is a need to predict which subjects are at risk for severe reactions. In this study, possibilities for 'component-resolved diagnosis', based on sensitization to different allergens in hazelnut, are discussed.


RESULTS
One type of hazelnut allergy can be associated with sensitization to homologues of pollen allergens, predominantly birch, in hazelnut: Cor a 1 (Bet v 1) and Cor a 2 (profilin). These allergens account for relatively mild symptoms. However, subjects can also be sensitized to several other allergens in hazelnut that are related to more severe symptoms. These allergens are homologues of allergens in other nuts and peanut: Cor a 8 (lipid transfer protein) and Cor a 9 (11S globulin) and perhaps Cor a 11 (7S globulin). The clinical relevance of these and other potential hazelnut allergens has to be further defined. The diagnosis of hazelnut has to be confirmed by oral double-blind placebo-controlled food challenge.


CONCLUSIONS
Sensitization to hazelnut can either be associated with mild oral symptoms, depending on sensitization to pollen, or with more serious allergic symptoms, related to sensitization to homologues of nut and peanut allergens.
Flinterman
Annebeth E
AE
Department of Dermatology, University Medical Centre Utrecht, Utrecht, The Netherlands. a.e.flinterman@umcutrecht.nl
Akkerdaas
Jaap H
JH
Knulst
André C
AC
van Ree
Ronald
R
Pasmans
Suzanne G
SG
D000707:Anaphylaxis / Q000175:diagnosis / Q000209:etiology / Q000276:immunology / Q000503:physiopathology*; D000818:Animals; D052179:Antigens, Plant / Q000276:immunology / Q000378:metabolism / Q000627:therapeutic use; D031211:Corylus / Q000009:adverse effects; D003888:Desensitization, Immunologic / Q000639:trends; D003937:Diagnosis, Differential; D006801:Humans; D018716:Molecular Mimicry; D021184:Nut Hypersensitivity / Q000175:diagnosis / Q000276:immunology / Q000503:physiopathology* / Q000628:therapy; D011058:Pollen / Q000009:adverse effects; D012720:Severity of Illness Index; D040681:Structural Homology, Protein
D052179:Antigens, Plant