Swollen upper gum front under nose, what could this be?

Abscess: Likely an abscess. Get in to see your Dentist ASAP. It will only worsen, so make the appt. Good Luck.

See a dentist ASAP: A tooth abscess won't go away without treatment and the infection may spread to your jaw, cheeks, sinus, brain and to other areas of your head and neck. A dental abscess is a collection of pus that forms in your teeth or gums as a result of a bacterial infection. Dentist will treat a tooth abscess by treating the cause and getting rid of the infection. See your dentist ASAP.