H1N1 Flu Shot and Egg Allergy

My son successfully recieved his first dose of the swine flu vaccine without any egg allergy complications.  A couple of days ago I took him to the doctor for his second.  About a half an hour after we got home I noticed that his leg was swollen pretty bad around the injection site and it was red.  His whole thigh and part of his stomach was blotchy red, his nose was running, his leg seemed to really bother him and he just seemed to not feel well. I called the doctor and they told me to immediately give him Benadryl and put cold compresses on his leg.  Within an hour or so the symptoms began to go away, without any wheezing.  I was told that an egg allergy reaction to the flu shot doesn't always occur on the first injection, but shows up on the second. We were lucky that his wasn't serious. I was never told this, or else I would have waited a while at the office before coming home. I'm glad that he is now vaccinated and I think it's important for all parents do, but if your child has an egg allergy please be cautious and ask lots of questions. We felt a false sense of security after he recieved the first without any issues.