I have read and researched alot on anaphylaxis aswell as anaphylactic shock.
I have noticed that alot of sites have different signs and symptoms. Most of them agree within each other on the most common symptoms. Example. some websites say reactions can happen within 5 to 15 minutes or usually very soon, as other websites and texts state that reactions can happen from seconds or can be delayed upto 2 or more hrs. I have read that with delayed reactions the reaction can become more life treatening (this is true for me). I also tend to find with my delayed reactions I have bi-pashic reaction (a second reaction upto 6 hrs after the first one has been treated).
A really good informative website to look at is the Food Allergy & Anaphylaxis Network. http://www.foodallergy.org/