You are not my doctor and I am not asking for medical advice.
A few years ago I developed an allergy to aspirin and similar products. I had taken these pain killers as needed, not all that often, all my life, then one day I took some Aleve and had a pretty severe allergic reaction to it (nothing that required going to the hospital, but lots of facial swelling and snot, eventually relived by benadryl). I tried taking aspirin and advil after that and got the same reactions, and so have avoided these products since.
I was wondering, however, if it is possible to loose that allergy as spontaneously as it developed. I was extremely allergic to cats when I was a kid, and that went away. Could this be tested by rubbing an aspirin tablet on my skin or something to see if it gets irritated? What do we know about how allergies work?
It is my impression that drug allergies may get worse, rather than better. If you really want to know, ask an allergist to set up a test for you. The problem with testing your theory is that if, for some reason, your drug allergies have worsened, you could get into awful trouble doing it by yourself. If you get into trouble at a doctor’s office, he’ll be able to put you to rights again.
I was allergic (seasonally) to grass pollen since childhood, but I haven’t had a problem since ~2002, and I doubt I’ll have any in the future. Non-seasonal, product-specific allergies are different, so I agree with Quiddity Glomfuster that you should consult a professional for details.
You could always infest yourself with hookworms.