Food Allergies!!!!!!! 13mo allergic to something but what?????

[aideesmum]

My 13mo ds has twice now had a severve reaction to something he has eaten, his lips swell up and the first time he had to have an adrennalin shot as his breathing got difficult (both times got rushed to hosp - 2nd time was just a precaution after the 1st time).
The first time he was 11mo and had Tuna Pasta Bake made at Nursery but has had it again since and had no reaction. This time (yesterday) it was scrambled egg on toast made at nursery but has had eggy bread before there and had no reaction. Any ideas please? It seems he can have the foods one time and be fine but another time he will have a reaction. Got a hospital appointment in 6 weeks time to get him tested but can't wait til then and don't know whether to stop him from having certain foods?
Anyone had this before?
Also it only seems to happen when he's eaten at nursery but prob just conincidence. I know dread any calls at work incase it's the nusery again.
Help!

well stop eggs for a start would be my advice
If your ds does hav such a serious allergy its owrth cutting anything that is a common allergenic, like eggs nuts etc
Could be the difference in cooking my dd reacts seriously to raw egg but not to cooked eggs.
So sounds like the likely culprit

my son reacts to partially cooked eggs and preservatives but not to my own cakes which the eggs are very cooked. Done allergy testing not nice but did show egg protien allergy./

Also my dd never reacted the first time or two she had egg in baked goods - only the 3rd time, I was very careful about introducing it.