Yes, this does sound like it could be acne but usually the areas will be black and look like pepper. My Sunny has had several episodes but nothing serious to require a vet visit. I now use only stainless steel bowls and I also wash the food bowls each time after they eat which is twice a day and their water bowls once a day. I also put the bowls in the dishwasher once a week. So far this has helped Sunny's acne a lot and he's now acne free.

When I had to wash Sunny's chin I used some Hibiclens which contains chlorhexidine gluconate and this is supposed to help the acne. If you're still unsure about Angel's chin, then you may want to call your vet's office and just let them know what is going on. She may also have a food allergy and may be scratching her chin and this is causing the scabs that you've been seeing. Good luck and please keep us updated.