When your DH taps on the tooth, does it hurt? Is it painful with cold, hot or sweets?
All of these things can point to a badly infected tooth. It certainly can give him a sore throat and swollen lymph glands.
Antibiotics will only work with that kind of an infection for so long. It will reoccur unless properly addressed. He really should get to a dentist and have the tooth checked with a xray to see if there is an infection at the root.
Best to you and him,
Seeing a dentist to find out source of dental infection is advised.