My friend is allergic to dogs and believes that if he hangs around them more, he will become less allergic. Is this just wishful thinking?
This is just anecdotal, but it’s been my experience that repeated exposure to an individual animal makes my allergies diminish, but only for that particular animal. I have allergies to both cats and dogs. I live with both cats and dogs. My own animals don’t make me sneeze anymore, but when I’m involved with the pet rescue group to which I belong, new animals often give me trouble, and I have to take antihistamines and use an asthma inhaler.
You may become less allergic to something or you could become more sensitive, and blow up so big you can’t breathe and your skin is ready to pop. At that point they have to suppress your immune system.
I get “desensitization therapy”, a.k.a shots, for several allergies. As I understand it, the frequent exposure is wearing away my “ability” to defend against these things, meaning it’s making me able to tolerate the allergens without allergy symptoms.
I had a cat allergy, and for some reason involving stupidity we started adopting and helping strays and motherless kittens, in a sort of a home cat rescue mission. After a few years I started testing negative for cat allergy.
But I’ve also read that allergic symptoms have a funny nonlinear dependence on allergen exposure that can have positive or negative slope and one slope in the short term but another slope in the long term.
I read somewhere that the supposition that desensitization therapy is useful has never been demonstrated experimentally. This may sound far-fetched at first, but medicine and science do differ in that medical treatments that are thought to be helpful can’t be denied to people who want them, so in one sense experiments can’t be done ethically. A less oversimplified statement of this should take pages of thoughtful writing from someone way better informed than I, but I have heard of various other quirks of medical research that follow a similar thread. For example, I’m sure I read in Scientific American about 10 years ago that there were actually no experiments demonstrating that chemotherapy helped fight cancer for this reason.
I also read somewhere that if your mother had allergic symptoms during her pregnancy with you, you are likely to suffer from allergy yourself. But if she has no allergic symptoms during the pregnancy, you are much less likely - whether that is because she has no allergies or just because she happened to avoid exposure during the pregnancy. So, it’s not whether Mom has allergies, it’s whether she suffers symptoms during the pregnancy itself.
The theory is, and there is data to support it, that regular exposure to an allergen modifies the allergic response.
In the anaphylactic allergy response, the reaction is mediated by the IgE antibody, which triggers the release of mast cells, and causes life-threatening reactions.
Chronic low-level exposure can alter the response, so it’s mediated by one’s IgG antibodies, which don’t cause mast cell degranulation, and don’t engender life-threatening reactions.
This therapy does make a clinical reduction in response to allergen exposure in 50% of the cases.