I must admit this is something that I'm not familiar with. I've seen angio-oedema - a severe allergy reaction which causes swelling of the lips and tongue - but not a condition which just causes itching of the roof of the mouth. I took comfort from the fact that Sara89022's doctor was stumped too.
This is a companion discussion topic for the original article at https://patient.info/news-and-features/itchy-roof-of-mouth-oral-allergy-syndrome