How long does a food allergic reaction last?

How long would it be before i had and allergic reaction to food if i were going to?

• when i was little i had an allergic reaction to walnuts and my throat swelled up and i had to go to the hospital. i've avoided them like the plague since, but today i accidentally ate a little i didn't see that was in some frosting of a cake. it's been like 1 1/2 hours now, my thoat is bothering me a little, but thats all. i was wondering if this is all that will happen, or if it takes more time than that?

• Answer:

  Generally an allergic reaction happens within a half hour, usually quicker, of eating the culprit. It sounds like you may have had a small reaction, but didn't eat enough of the walnuts to warrant a trip to the ER. I think you have made a wise decision by avoiding walnuts altogether. Next time it is possible that an even smaller amount could cause a reaction. Better to be safe than sorry. Your past reaction was classic signs of allergic reaction.