I am not sure about the specific case of poison ivy, but children have a higher prevalance of some allergies compared to adults. In the case of food allergies, 2-3% of adults have food allergy in the US, while about 8% have them as kids. In this case, the difference is typically blamed on differences in digestion, but I think this is an incomplete answer. Our immune system is very complex, and our understanding of allergy is not very advanced. This is evidenced by our inability to cure this disorder. The antibody type responsible for most allergic reactions (IgE) is the same antibody type used to combat parasitic worms in our bodies. In countries where parasitic worms are common, people do not have allergies, and those that have bad allergies are great at fighting parasitic worms. Research to combat auto-immune diseases (IBS in particular) have even found that patients that are given large quantities of pig parasitic worms (eggs) that cannot complete its life-cycle in humans, experienced a remission of auto-immune disease symptoms. Cool stuff...
Last edited by RAH; 06/27/10 06:51 AM.
