How to test a nut allergy.

Growing up, I was always told that I had a nut allergy and would go into anaphylaxis if I ate one. In my early teens I had a scratch test with a slight reaction to walnuts and the doctor said the best way to test would be to eat some peanut butter in a hospital room with a crash cart ready but if I did go into anaphylaxis, there was a 50/50 chance I’d never leave the room alive. It’s about 30 years later. I think I have accidently eaten slight amounts (half a chocolate) of walnuts and I really want to know if I am still allergic to nuts. Mrs Cad is trained in CPR and I have Kaiser so what’s the best way to do this considering even if the scratch test came back negative I’d still would have to eat nuts to be sure.

FWIW I asked my mom and I never had an reaction because I never ate a nut so I don’t know why she was so sure that it would be that serious of a reaction.

See an allergist. They can decide if you can be challenge tested under close medical supervision. And restart your heart if necessary. Or if perhaps a simple RAST blood test for various nuts would be sufficient.

eat a Payday candy bar in the ER waiting room.

or go get another allergy test, focused on nuts, from an allergist.

Well The Children’s Hospital at Westmead suggests

In most cases the clue to peanut allergy is the start of symptoms soon after exposure to peanut product. The presence of allergy IgE antibodies to peanut can be confirmed by an allergy skin prick test or a blood test (called a RAST test). It is important to realise that not every child with a positive allergy test will develop symptoms on exposure to peanut product and the interpretation of the test should be discussed with your doctor. In some cases it may be necessary to confirm or exclude peanut allergy by performing a peanut food challenge in hospital. Your child’s doctor will discuss this with you if he / she feels it is necessary.

I recently heard a specialist being interviewed on radio. The interviewer mentioned that some people take their children to the hospital and give them a bit of peanut butter in the car to find out if they are allergic. I was horrified at the thought but the doctor didn’t think it was such a bad idea. Here is a news story about "peanut butter parties near a hospital.

Does not compute. Walnuts and peanuts are not even remotely close to being the same thing. A walnut scratch test will say something about whether you’re allergic to walnuts, but says nothing about whether you’re allergic to peanuts. Eating peanut butter will say whether you’re allergic to peanuts, but will say nothing about whether you’re allergic to walnuts. There’s some correlation between allergies to the true nuts, but hardly any of the things we call “nuts” are true nuts, and even among the true nuts, it’s still possible to be allergic to (say) hazelnuts but not chestnuts, or vice-versa.

Speak to your GP or a properly qualified allergist about it, and ask if there’s any way they would validate you testing yourself on either their premises or in the ER. They’d probably say no, but that’s the only way I can really see you being covered by your health insurance or (if the worst happened, which it almost certainly won’t but you have to take it into account) your life insurance company.

Or if they say nah, you’re fine, just eat nuts, then you’re still covered financially should something bad happen.

It is strange that those with peanut allergies (legumes) have an increased risk of allergy to tree nuts, when the only thing they seem to have in common is that humans call them both nuts.

The ONLY way to determine if you have a specific food allergy is with a food challenge. The RAST test and serum IgE will tell you if you MIGHT have an allergy. If those are negative, you do not, but if positive you might. If it is really that important to you go see an allergist. They will do the blood and scratch tests, and if those are positive would be perfectly happy to give you a food challenge in there office.

To test for a severe peanut allergy, have someone give you a food without you knowing whether or not it contains peanut. (You’ll have to decide whether or not it’s worth taking the risk to actually test that way.) Statistically, fewer people die of peanut allergy per year than lightning strike, and peanut allergy in general seems to be more of a plague in countries that have lots of food available, and lots of creature comforts (making it harder to find things to worry about).

In a quarter century of seeing patients, I don’t even remember a truly severe (life threatening) peanut allergy before it became such a popular reaction to own. I have seen a number of spectacular hysterical reactions, and a couple of near-fatal reactions to injections of epinephrine done in panic by emergency responders called to “life-threatening” allergic reactions. This is an experience of one, and therefore anecdotal, obviously.

That isn’t to say such a thing as severe peanut allergy does not exist, but as with many “severe, life-threatening” allergies, the secondary gain of owning such a condition along with the hysteria should a reaction of any kind (even one due to anxiety alone) occur, makes identifying a true allergic reaction almost impossible without a double blind test.

See here for what I consider a reasonable perspective.

As a life-long allergy sufferer I strongly recommend going to an actual allergist for any sort of allergy testing, even if life threatening reactions aren’t a factor, even more so if that is a concern.

Much as I am tempted to say, “try deez nuts,” I have always heard that this sort of testing should be done under an allergist’s supervision because of the risk of worsening the reaction.

Update:
Went to the allergist and no reaction to the scratch test - but very small (too small) a reaction to the control scratch so they did the blood test. I get the results back this week and then depending on the numbers I’ll do a real “eat a nut and try not to die” test.

Yes, English language plant (and animal, fwiw) nomenclature is simply nuts. Pineapple trees aren’t a kind of pine tree nor a kind of apple tree. Grapefruits aren’t grapes, they are citrus fruits related to the orange and lemon.

Berries are another major food category where there is a big difference between botanically “true berries” and colloquial berries. Watermelons, tomatoes, and pumpkins (which often aren’t even considered fruits in colloquial usage) are “true berries” according to a botanist. Strawberries aren’t.

They are both germinators, for lack of a better term, and people who are allergic to them are also at a statistically higher risk for soy allergies and sesame allergies. My husband, who is not a doctor, but who does have a degree in biology, is that seeds have high concentrations of phytohormones, and those could be what trigger allergies in people. That would explain why of all things we call “berries,” strawberries provoke allergies pretty frequently, since they have seeds, albeit vestigial ones, on them. Having said that, I’ll admit I have no idea what the phytohormones status of strawberry seeds is. IIRC, there are two phytohormones in high concentration in seeds, but I don’t remember their names. Now, why nut and legume allergies would seem to be common, while rice allergies are not, I don’t know.

Marketing and population. Rice allergies are actually on the rise in Japan and China. It’s not entirely uncommon here in people with multiple cereal allergies.

I suspect there’s also something going on because we tend to eat white rice - the almost protein free (6%) endosperm - instead of brown rice, where most of the bran and protein are intact. Nuts don’t have an easy way to avoid the triggering proteins like rice does.

Which is what my allergist said but I eat soy and sesame with no problems. Fingers crossed.

I know you cook a lot, Cad, so, data not being the plural of anecdote, and all, but my son’s doctor said once that she thought allergies in general were on the rise because people tend not to cook from scratch much, so there’s not a cloud of food particles in every house, essentially inoculating babies against later food allergies, by exposing them to foods in minute amounts before that are eating solid foods.

It works for us. Our son hasn’t a food sensitivity to speak of, and we cook a lot, because we’re vegetarians, and keep kosher. There was lots of home cooking when I was growing up, and my immediate family, as well as most of my extended family kept kosher, so there weren’t as many eat-out options (even though we were in New York, where there are some). Albeit, my mother let us eat non-kosher food on things like road trips, as long as it was “kosher by ingredient”-- eg, we could get a fast food hamburger, but not a cheeseburger, or a fish sandwich with cheese.

My allergist talked about the idea of building up immunity through such casual encounters. There maybe something to that because we have nuts in the house although on principle I refuse to cook with them except for Mrs Cad’s birthday cake (banana-walnut cake with ginger buttercream frosting).

But then again we never had nuts in the house growing up and I had a tolerance for them by teenage years and how there are still cases of people going into anaphylaxis even by kissing someone who ate nuts/shellfish/etc. My allergist said that it is no coincidence that such extreme reaction occurred when instituting no nut zone. Except if so many people have a nut allergy, why is it that it is nearly impossible to get a baked banana product (bread, muffin, pie, cake) without nuts?

So walnuts are measured in units called chocolates?
I am sorry, I have nothing more to add. I hope you don’t die.

Are there actually, though? My understanding is that although these incidents get reported in the news occasionally, it always turns out to be something else, and there’s never been an actual case of this.

Cad,

Just FYI. The control scratch is dilute histamine, which mediates the anaphylactic reaction. Since it was too small it could be that you are anergic. Thus the blood test, which will check for allergen specific IgE.

If they are not allergic to something, at present, it is best to let them have continued exposure.