Peanut allergies have plummeted in children

Eating peanuts reduces allergies, but getting peanuts on your skin increases allergies.

https://www.sciencedirect.com/science/article/pii/S009167491...

Or maybe in your lungs.

https://pmc.ncbi.nlm.nih.gov/articles/PMC8429226/#R7

Yes, and this is one reason why eczema is correlated with allergies, because it allows allergens to pass through the skin more readily. And it's probably also a reason why babies put everything in their mouths; they're training their immune systems.

So you’re saying I should’ve eaten the cat that lived in my apartment when I was a baby?

:)))

It's possible that if you had more cat dander in your mouth when you were a baby that you wouldn't have developed an allergy. Or, more likely, if you had more mouth exposure to other natural microbes that occur outdoors and around animals, then you would have fewer allergies overall. That is well supported by the evidence.