In article ,
Silvan wrote:

I've always wondered whether or not I'm allergic to poison ivy. I've been
in woods and gardens as long as I can remember. I'm always vigilant about
spotting and avoiding it. When I do get into it, I come home as soon as
practicable and get in the shower. I take all the precautions, and I've
never experienced a rash, but I still wonder if it's my precautions, or
some inate lack of sensitivity to the irritant.

Your precautions can help maintain "inate lack of sensitivity". Once
upon a time, I could use creosote (nasty carcinogenic preservative they
don't sell to the public anymore) with impunity, and I did. One day, I
could not. Probably just as well (it is nasty stuff) but I went from no
reaction to pretty severe reaction, without any sort of transition.

--
Cats, Coffee, Chocolate...vices to live by