Just plain crazy

We have discovered that my son is allergic to peanut butter.

Did you all just picture the sheer bloatedness of a two-year olds face when they eat something they are allergic to? Because it's a horrible sight, let me tell you.

At the age of one, because my mother is an old-school mom and doesn't give a shit what docs say ("I gave you peanut butter when you were three months old and you were fine!") my mother gave my son a peanut butter sandwich. And he was fine. I told her never to give it to him again if I wasn't around, or I'd have to kick her in the knees. She might have listened, I'm not sure. I do know she gave him Nutter Butters, (which I love) and still, nothing. So yay! My son wasn't allergic to peanut butter!
Then one day when he was still with the old babysitter, she gave him a cookie when we were walking out, and he seemed to swell a bit after the cookie. I gave him benadryl and he was cleared up in seconds. I called the babysitter to ask her what kind of cookie it was, she said it was a homemade peanut butter cookie.
There was one day I made my son a peanut butter and jelly sandwich because that was what his daddy was eating for lunch, he took one bite and spit it out. He wouldn't eat the sandwich.
Another day we were at my sister's house, and she eats peanut butter off a spoon, something she has done since she was a kid. (Households having peanut butter and no bread to put it on...) My son asked for a lick. We got into the car and headed out for a drive, and in the car my son's head grew three sizes. You already know the phonecalls to the doctor that were made, the quick stop at the pharmacy for benadryl because I wasn't carrying it with me...the waiting for the swelling to go down, the guilt my sister felt. Ten minutes later he was fine, sleeping from being doped up.
So no peanut butter for my son.

But here's the weird thing, he isn't allergic to peanuts, or any nuts for that matter. It must be something IN the peanut butter. My husband was eating a cookie that had walnuts in it, gave the boy a bite (okay like five bites) and then I yelled at him ("Oh, shit I forgot..."), and we watched and nothing happened.
One day one of Daddy's friends gave my son a few peanut M&M's (why do people just hand things to kids???) and when I noticed, the kid had swallowed them before I could take them away. So we watched. And nothing.
I have to remember to ask his doctor about this...for now I will ask you guys if you have gone through this with any allergies with your kids. (I keep forgetting because the only time I talk to the doctor is about an ear infection or puking... yeah, horrible mommy...)