J.F.
My kids haven't had this, but my ex-husband did. He has a compromised immune system and I had a cold sore. He insisted on kissing me anyway and ended up with cold sores that spread into his mouth and throat, then ended up with Bell's Palsy. The doctor said it was the herpes virus that affected the nerves on that side of his face. It only lasted a couple of weeks and then he was fine. It hasn't happened since and that was 14 years ago. Don't be overly concerned. It should resolve itself soon.