A good, more thorough definition...are we boring anybody yet? I do understand the mechanism that explains "immunity" and why repeated exposure results in greater damage, but I don't feel like trying to write it out all here.....LOL ~~trisha ----- Original Message ----- From: "Jim Stamm" To: Sent: Friday, January 11, 2002 10:21 PM Subject: Re: [Az-Geocaching] Poison Oak/Ivy > Trisha Radley wrote on 1/11/02 7:15 AM : > > >Actually, that is a good example of how the body develops an allergic > >reaction/response (like beestings). The first time you are exposed, you have > >no allergic antigens to the offending substance, and your body develops > >these so that the next time you are exposed, your body has developed a > >"memory" in its immune system and attacks the substance...hence the allergic > >reaction. Not sure I explained that very well, but its early! > > Good explanation, but it's a little more complicated than that. The > oils/chemicals from the poison ivy are not harmful to the skin, do not > cause any symptoms, and do not cause antibodies to be produced. The > invading chemical is "digested" (bad word), on the skin, and reacts with > the skin proteins. The resulting components are manifested as "foreign" > to the body's immune system. This usually takes hours, so there is time > to wash the junk off (if you know it is there.) > > Now the immune system sends white blood cells to the "foreign" area, > where they end up attacking everything in the area. This is what causes > all the damage. > > I don't remember the mechanism that explains "immunity," and why repeated > exposure results in greater damage. > > -Jim > _______________________________________________ > Az-Geocaching mailing list > Az-Geocaching@listserv.snaptek.com > http://listserv.snaptek.com/mailman/listinfo/az-geocaching >