Yes there are doctors there. PM me if you would like the names.
What a wise vet! I think there is someone who posts here who is from PA, but I don't know which part. Perhaps they will see your inquiry.
If you google for something like "Lyme Pennsylvania" or "LLMD Pennsylvania" you will find a lot of links, some outdated, but it's a place to start. If you come up dry, let us know.
w w w [dot] lymediseaseassociation [dot] org has a referral service you could try. I haven't used them, but it's been around a while.
Good luck to you.