Thought I'd start this with a link to an Allergic Living article . . .
Please feel free to add any new-ish studies or other pertinent discussion.
http://allergicliving.com/2010/07/02/oral-allergy-syndrome-cross-reactions/ (http://allergicliving.com/2010/07/02/oral-allergy-syndrome-cross-reactions/)
(Secretly hoping that a high-pos SPT for hazelnut with very high birch SPT may mean that NOT allergic after all to hazelnut . . . and trying to figure out how to get allergist to agree to oral challenge of hazelnut . . . )