Can you use lotrimin on my dog?

More than likely it is folliculitis (an infection of the hair follicles). I found the most convenient and economical way to treat the condition is oxy/acne pads. The best type of food/water bowl is stainless steel. It prevents the repeated rubbing irritation that can be caused by plastic bowls. Good luck!

Probably not a good idea without checking with your vet first.

Lotrimin is an antifungal cream and if the bumps on your dogs chin are a reaction to the feeding bowls it will not help at all (and could make it worse).