Just talked to the vet--amazingly, she didn't ask me to come in so she could see it and charge me $100!!
She said to wash it with a mild soap (of course nothing in the house was good enough, so I had to run out and buy some), and give her 25mg of Benadryl.
She said it's possilbe that with the area being shaved, something could have irritated it that otherwise wouldn't have.

When they are all done playing I will wash her and medicate her!!