Hubby has sore throat on one side no other syptoms, doc said he could see a boil like thing. took antibiotic went away now it's back. what could it be?

Needs a re-check: One-sided sore throat, with a visible lesion, not resolved with antibiotic, brings to mind a couple if possibilities. One is a possible abscess. An abscess would need to be treated in the Emergency Room by an ENT specialist. The other thought would be evaluation for a tumor. In both instances, and in light of him not being better, he needs to be re-evaluated. If his voice is affected go to ER