I would suggest seeing a doctor because it could be a symptom of something more serious. Most likely, your doctor will put you on antibiotics or send you to an oral specialist. However, I'd probably gargle with warm salt water to try to keep it as clean as possible.
You should see your dentist immediately. It could be an allergic reaction, or a polyp, or a virus, or any number of other problems. The dentist can further diagnose and provide the proper treatment or referral to a specialist.
You should find out what caused it, and act fast before it spreads to the near tissues. It can be caused by either bacteria or viruses, so it's best to head to the doctor's office, so he can check up on it.
Take multi-vitamins tablets as infection can be due to insufficient vitamins from your daily diet. Don't take spicy or oily food as they will affect the healing process.
