Bubble on my pinkie finger?

Okay, so I think i have poison ivy on my ankles, and I've been madly scratching it. Now I think that it's on my hands. Only like five little red bumps are on the backside of my hand, and there is just one bump that seems to stand out. It's on the side of my pinkie finger and it looks like a bubble with some clear stuff inside of it. It's also kind of red. What is it? It can't be Scabies because my hands look nothing like one with Scabies.