Why do poison ivy rashes so often start between our fingers?

I realize it's a more sensitive area, but does the plant actually have to come into contact with skin there? If it's oil on my hands, why doesn't it start on my palms or elsewhere? I don't go around sliding leaves between my fingers, so what's up?
Answer:
Poison Ivy rashes will develop on thinner skin before it starts to appear on thicker skin. In terms of your hands, this would imply it will appear between your fingers before your palms, because the palms are much thicker. The oil from the plant actually seeps into your bloodstream, which means that you could potentially erupt somewhere you didn't even touch, but you will definitely erupt where you did come in contact with the oil. To clarify though, the fluid inside the blisters will not "reinfect" you. It's best to let nature run it's course, but if a few pop open, which eventually they will just start to ooze anyway, it's not going to spread it.

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