[ilickpoolalgae]

My kid is allergic to peanuts (we did a peanut butter test at about 5 months and had to rush him to the ER as his face started swelling up). Food allergies are a really interesting subject because it doesn't seem entirely reliant on genetics. For example East Asians have an extremely low rate of peanut allergies, but East Asians who grow up in western countries tend to have an equal or higher rate of peanut allergies compared to the general populace. Strangely enough, children that move to Australia after the early infancy period seem to retain the same low rate of peanut allergies as children who spend their entire time in China. https://pubmed.ncbi.nlm.nih.gov/26728850/

There's a great clinic in the bay area called Latitude that conducts oral immunotherapy which is a fancy word, afaik, to do slow introduction to foods that you're allergic to. My child is on a 6 month program that he started at 1 year old to slowly increase his peanut consumption, via peanut flour, to a couple peanuts a day.

[xyzzyz]

Very interesting. While the theory that most peanut allergy is caused by no exposure in infancy is well supported by the evidence, seems like it’s definitely not the entire story, given your experience — after all, you could hardly have a lot of exposure in children to peanuts earlier than 5 months! I don’t think we were feeding our kids solid foods at 5 months yet at all, so definitely they had no peanut exposure yet, but nevertheless they don’t suffer from allergies. The evidence you are pointing to about disparate rates of allergy for children growing up in different places is also very interesting. Sounds like there just is something in the air, or dirt, or daily practices, or whatever else it is, that causes those allergic immune reactions at elevated rates in western nations.

[rdedev]

Exposure need not come from only peanuts. Other compounds or organisms can have similar structures. My hypothesis for why allergy is more prevalent in the US mostly comes down to how clean everyone keeps their homes. Clean as in using clorox or other anti bacterial over all surface clean. Stuff like that are rarely done in Asian countries. But hey, I'm not a scientist so I am possibly wrong or missing something

[jraines]

Same experience. My wife ate extra peanut butter while pregnant and nursing (offtopic but maybe relevant), and we tried giving my daughter the tiniest dab of peanut butter very early, and the reaction was nuts. We watched with rising panic as the inflammation started at her mouth, traced down throat and chest to stomach, and spread, in what seemed like real time.

She is 3 now has to have an epipen ready to go. 2nd girl: no issues at all - same house, basic maternal diet, vaccine schedule, etc

[le-mark]

Same here, nearly killed our son at 5 months with a few crumbs of peanut butter cookie. Other kid no problem. Really seems like there’s more to it than simply early exposure.

[Balgair]

Adding our horrific experience here too. Gave our baby a little bit of peanut powder at 7 months. About 2 hours later, vomiting like crazy, turned about as grey as a rain cloud, rushed to the ER blowing through stoplights.

We have never been so scared in our whole lives. Facing the very real loss of a child due to your own hand is a thing you never want to go through. I unreservedly have some good trauma from that experience. Took about a week to get back to normal, the dehydration was so bad and they could not get a vein for IV fluids.

We carry an epi-pen everywhere now.

Fun Fact: Allergy tests (IgG and skin prick) have a ~10% false negative rate and a ~50% false positive rate (!!!).

[LUmBULtERA]

Adding to this list here as well... momma had peanut butter and jelly sandwiches nearly daily while pregnant and breastfeeding, and yet my son's first exposure to peanut butter as soon as he was able to safely have solid food showed he was allergic.

[canes123456]

As with all things it not a panacea. The studies only see that peanut allergies decrease with early exposure. However, there always some kids that will have or not have allergies in both groups.

[geraldwhen]

Same here. Early introduction -> emergency room.

[nickelpro]

> the theory that most peanut allergy is caused by no exposure in infancy is well supported by the evidence

The evidence supports this as one source of allergies. The cited study says 77% of such allergies may be sourced to lack of exposure, that still means almost 1/4 people with peanut allergies have them "naturally"

[xyzzyz]

Yes, that’s what the word “most” means in the sentence you quoted.

[hammock]

>you could hardly have a lot of exposure in children to peanuts earlier than 5 months!

Don't have a baby, but couldn't you put a few drops of unrefined peanut oil in the bottle? Or a quarter teaspoon of peanut butter?

[blondin]

has anyone looked into the source of the peanut products? sounds like the US is dis-proportionately affected by these allergies.

[petodo]

Yeah, it doesn't seem to be hereditary, both me (European Caucasian) and my wife (Chinese Asian) have 0 problems with nuts and can crunch them as much we want (same with everyone in direct line), but both of our kids have very strong nut allergy (not just peanuts, also pistachios, walnuts and especially cashew nuts) with immediate swelling, whole body red, very dangerous, even just piece of peanut. Also interestingly son spent 1st year of life in China, while daughter was born in Europe and it doesn't seem to make any difference.

Before I had kids I heard in Europe about peanut allergies only from US movies and TV shows and never met person who would be allergic to them, so was shocked to find my kids having such "made up" US allergy.

[chunk_waffle]

> For example East Asians have an extremely low rate of peanut allergies, but East Asians who grow up in western countries tend to have an equal or higher rate of peanut allergies compared to the general populace.

Interesting... my wife is East Asian and has no history of Peanut allergies in her family. Same for my family (Caucasian, US) yet our daughter is allergic.

My wife also ate a lot of peanut butter while pregnant...

[brianherbert]

Same here, no peanut allergies on both sides of our family but one of our daughters has a peanut allergy. We are the same mix.

[adamredwoods]

We also tried to give our child (when a baby) peanut butter early and was rushed to the ER. Terrifying.

[chunk_waffle]

I'm wondering why the article doesn't point out that risk either. If your child is 3-5 months old and is severely allergic (but you don't know it yet) it seems like they could have a severe reaction to even a small amount of peanuts.