Please go to your vet to take a sample und check under microscope. I had the same think on my CC but probably is not the same. Please watch his skin everywhere to see if is coming out on some other places, not only on his chin. They look like pimples (I use to squeeze them like the pimples and disinfect) but when they start coming on one of the legs and lateral body I went to my vet.
They took a sample from his skin and they found DEMODEX.
Demodecia (demodex canis)
All dogs care this on them but is coming out on the dogs with week immunity system, in general on puppies until 7-8 months (According my vet).
The treatment takes to months minimum, I use to have an injection every 3 days and some pills (VETO Immune and VETO Skin). In two months they all disappear and the fur start growing back.
It happen in Europe, I have no idea what and how is in USA.
I wrote in case they vet will diagnose the dog with demodex. You will probably find a cure for local treatment but the dog need immunity boost.
I hope you won’t have what I had with my dog.
All the very best!
Edward