A peritonsillar abscess is a bacterial infection that usually begins as a complication of untreated strep throat or tonsillitis. A pus-filled pocket forms near one of your tonsils. It can cause pain and may be visible.

Peritonsillar abscesses are most common in children, adolescents, and young adults. They often occur at the beginning or end of the winter season, when illnesses like strep throat and tonsillitis are most widespread.

Peritonsillar abscesses usually occur as a complication of tonsillitis. If the infection breaks out of a tonsil and spreads to the surrounding area, an abscess can form. Peritonsillar abscesses are becoming less common due to the use of antibiotics in the treatment of strep throat and tonsillitis.

Mononucleosis (commonly referred to as mono) can also cause peritonsillar abscesses, as well as tooth and gum infections. In much rarer cases, it’s possible for peritonsillar abscesses to occur without an infection. This is generally due to inflammation of the Weber glands. These glands are under your tongue and produce saliva.

Read more: What’s the difference between tonsillitis and strep throat? »

The symptoms of a peritonsillar abscess are similar to those of tonsillitis and strep throat. But with this condition you may actually be able to see the abscess toward the back of your throat. It looks like a swollen, whitish blister or boil. Symptoms of a peritonsillar abscess include:

  • infection in one or both tonsils
  • fevers or chills
  • difficulty opening the mouth fully
  • difficulty swallowing
  • difficulty swallowing saliva (drooling)
  • swelling of the face or neck
  • headache
  • muffled voice
  • sore throat (usually worse on one side)
  • swollen glands in the throat and jaw (tender to the touch) and ear pain on the side of the sore throat
  • bad breath

Peritonsillar abscesses could cause severe symptoms or complications. Rare and more serious symptoms include:

  • infected lungs
  • obstructed (blocked) airway
  • spreading of infection to throat, mouth, neck, and chest
  • rupture of the abscess

If you don’t treat the abscess in a timely manner, it can result in infection throughout the body. It can also block the airway even more.

Even though some of these symptoms may be signs of other problems, such as strep throat, you should contact your doctor so they can make the final determination.

To diagnose a peritonsillar abscess, your doctor will first perform an examination of your mouth and throat. They may take a throat culture or a blood test to diagnose your condition. Signs of an abscess include:

  • swelling on one side of the throat
  • swelling on the roof of the mouth
  • redness and swelling of the throat and neck

Lymph nodes are often enlarged on the same side.

Your doctor might also order a CT scan or MRI to see the abscess more closely. They might also use a needle to draw fluid from the abscess. This fluid will be tested to check if there is an infection.

To prevent an abscess, it helps to begin treatment for tonsillitis immediately. Your chance of getting an abscess increases when you delay treatment for tonsillitis.

You should also get treatment right away if you contract mono to help prevent further complications. Make sure to brush your teeth and get dental checkups to keep your teeth healthy. Smokers are also more prone to peritonsillar abscesses. Keeping your mouth clean and healthy and not smoking can help to reduce your chance of developing an abscess.

Antibiotics are the most common form of treatment for a peritonsillar abscess. Your doctor may also drain the pus in the abscess to accelerate healing. This is done by lancing (or cutting) the abscess to release fluids. You doctor may also use a needle. ENT (ear, nose, and throat) surgeons usually perform these procedures.

If you are unable to eat or drink, you may have to receive fluids for hydration intravenously (through an IV). Your doctor may also prescribe painkillers if you are experiencing a lot of pain.

As with chronic strep throat and tonsillitis, when abscesses are reoccurring, your doctor might recommend removing the tonsils to avoid future, and more severe, infections.

Read more: 12 natural remedies for a sore throat »

If you received treatment, a peritonsillar abscess normally goes away without causing more problems. However, you could get the infection again in the future.

If it isn’t treated quickly, you may experience complications from a peritonsillar abscess. These include:

  • obstruction of the airway
  • bacterial infection in the jaw, neck, or chest
  • bloodstream infections
  • sepsis
  • death

If you are having problems with your tonsils, talk to your doctor about possibly removing them. Pay attention to any pain or changes in your throat area and remember that the key to treating peritonsillar abscess is early detection.