Hi My Son Is 29 He Has A Very Sore

Hi my son is 29 he has a very sore throats and has swollen gums which is very concerning as his oral hygiene is perfect and has never had dental issues. His throat has been sore for 2 weeks, his gums swollen for 5 days and inflamed and glands sore under chin. I have tried getting an appt with go but non available until new year. Could this be strep throat? I do have fluoxocillin should I give him this course can you please advise thankyou