Skin Problems White crust under chin???

So I was checking on my piggie Flora this morning and notices something odd with the under side of her chin and neck. The fur was all clumped together and there was white crust everywhere. I gave her a warm shallow bath to clean it off, then tried to clean it with some Q-tips, and then dried it and put antibiotic on it. The only weird thing I noticed was that the Q-tips were yellow after using them on the crustiness.
I've had guinea pigs get abscesses under their neck before that I've washed and cleaned out, but I couldn't find a scab anywhere where the abscess would have popped, and it just didn't really look like one. The only other idea I had was that since she was a sloppy drinker, maybe her chin just got really wet when she was drinking and then got infected from the cage being dirty.

She's been acting fine, she's eating, drinking, running around, and squeaking when I walk up to the cage. If it doesn't change or clear up by tonight I'm going to call the vet and set something up for tomorrow, but in the mean time if anyones got any ideas it would be super helpful. Thanks