Hi, my dd1 had an anaphylactic reaction to egg at 1yr. We'd been really careful about introducing all new foods individually, and had not introduced egg until she was 1yr. I gave her french toast on the first occasion; she loved it (hurrah, I though - A New Food). Second time (which is when reactions occur), she had red blotches on her mouth chin (alas, at the time I put it down to drooling!). Several hour later, her entire body erupted in a rash. I remember the car ride to the doctors, with her face swelling up like a balloon - we ended up in hospital, which was all very scary. One minute your life is going along normally - the next you are being trained in how to give artificial resuscitation to your baby!
The happy ending (for those in a similar situation) is that apparently in about 50% cases of egg allergy, the child grows out of it. We are in the fortunate position that Dd1 can now eat cooked egg (pancakes, cake, etc), and is old enough (7) to be very sensible about washing hands, etc when handling raw egg when baking, etc
We had 2 'egg challenges' at the hospital - the last 2 years ago when raw egg applied to the lip, began to produce a reaction, which we were able to pretty much halt with antihistine. I have to say our doctor wasn't brilliant (at one point she baulked at the prospect of prescribing a new epipen, "is she still allergic", then suggesting that we should find out by getting her to eat raw cake mixture. Needless to say we ignored her advice, and I thought myself very restrained not to slap her!
I found the security of doing the allergy challenges in a hospital really comforting - I knew that if something awful happened, we were in the best possible hands.
Agree with Desderata, that you need to be gentle (but very clear) with relatives - it's a learning curve.
good luck!