How to treat Poison Oak?

My wife and I went hiking a week ago, and apparently she got into either poison oak or poison ivy. We're not sure which, because we don't remember seeing either of them, but the blisters and itching is there regardless. What can we do to help fix it? It's on her neck in the front. We tried using a baking soda compress, but that didn't really do anything except make her skin burn a bit, it still itched. Here is a picture of the scars where they've formed: