Peritonsillar Abscess

Medically Reviewed by Robert Brennan on March 30, 2023
6 min read

A peritonsillar abscess forms in the tissues of the throat next to one of the tonsils. An abscess is a collection of pus that forms near an area of infected skin or other soft tissue.

The abscess can cause pain, swelling, and, if severe, blockage of the throat. If the throat is blocked, swallowing, speaking, and even breathing become difficult.

When an infection of the tonsils (known as tonsillitis) spreads and causes infection in the soft tissues, a peritonsillar abscess may result.

Peritonsillar abscesses are generally uncommon. When they do occur they are more likely among young adults, adolescents, and older children.

A peritonsillar abscess is most often a complication of tonsillitis. The bacteria involved are similar to those that cause strep throat.

Streptococcal bacteria most commonly cause an infection in the soft tissue around the tonsils (usually just on one side). The tissue is then invaded by anaerobes (bacteria that can live without oxygen), which enter through nearby glands.

Dental infection (such as the gum infections periodontitis and gingivitis) may be a risk factor. Other risk factors include:

  • Chronic tonsillitis
  • Infectious mononucleosis
  • Smoking
  • Chronic lymphocytic leukemia (CLL)
  • Stones or calcium deposits in the tonsils (tonsilloliths)

The first symptom of a peritonsillar abscess is usually a sore throat. A period without fever or other symptoms may follow as the abscess develops. It is not unusual for a delay of 2 to 5 days between the start of symptoms and abscess formation.

  • The mouth and throat may show a swollen area of inflammation -- typically on one side.
  • The uvula (the small finger of tissue that hangs down in the middle of the throat) may be shoved away from the swollen side of the mouth.
  • Lymph glands in the neck may be enlarged and tender.

Other signs and symptoms may be observed:

  • Painful swallowing
  • Fever and chills
  • Spasm in the muscles of the jaw (trismus) and neck (torticollis)
  • Ear pain on the same side as the abscess
  • A muffled voice, often described as a "hot potato" voice (sounds as if you have a mouthful of hot potato when you talk)
  • Difficulty swallowing saliva

Discuss any sore throat with fever or other symptoms with your doctor by phone or with an office visit to see if you have a peritonsillar abscess.

If you have a sore throat and trouble swallowing, trouble breathing, difficulty speaking, drooling, or any other signs of potential airway obstruction, you should go to the nearest emergency room.

A peritonsillar abscess is usually diagnosed based on history and a physical exam. A peritonsillar abscess is easy to diagnose when it is large enough to see. The doctor will look into your mouth using a light and, possibly, a tongue depressor. Swelling and redness on one side of the throat near the tonsil suggests an abscess. The doctor may also gently push on the area with a gloved finger to see if there is pus from infection inside.

Lab tests and X-rays are not used often. Sometimes an X-ray, CT scan, or an ultrasound will be performed, typically to make sure other upper airway illnesses are not present. These conditions may include the following:

  • Epiglottitis, an inflammation of the epiglottis (the flap of tissue that prevents food from entering the windpipe)
  • Retropharyngeal abscess, a pocket of pus that forms behind the soft tissue in the back of the throat (like a peritonsillar abscess but in a different location)
  • Peritonsillar cellulitis, an infection of the soft tissue itself (a peritonsillar abscess forms beneath the surface of the tissue)

Your doctor may test you for mononucleosis, a virus. Some experts suggest that mono is associated with up to 20% of peritonsillar abscesses.

Your doctor also may send pus from the abscess to the lab so the exact bacteria can be identified. Even so, identifying the bacteria rarely changes treatment.

There is no home treatment for peritonsillar abscess. Call your doctor for an immediate appointment to check your symptoms.

If you have a peritonsillar abscess, the doctor's primary concern will be your breathing and airway. If your life is in danger because your throat is blocked, the first step may be to insert a needle in the pus pocket and drain away enough fluid so you can breathe comfortably.

If your life is not in immediate danger, the doctor will make every effort to keep the procedure as painless as possible. You will receive a local anesthetic(like at the dentist) injected into the skin over the abscess and, if necessary, pain medicine and sedation through an IV inserted in your arm. The doctor will use suction to help you avoid swallowing pus and blood.

The doctor has several options for treating you:

  • Needle aspiration involves slowly putting a needle into the abscess and withdrawing the pus into a syringe.
  • Incision and drainage involves using a scalpel to make a small cut in the abscess so pus can drain.
  • Acute tonsillectomy (having a surgeon remove your tonsils) may be needed if, for some reason, you cannot tolerate a drainage procedure, or if you have a history of frequent tonsillitis.
  • You will receive an antibiotic. The first dose may be given through an IV. Penicillin is the best drug for this type of infection, but if you are allergic, tell the doctor so another antibiotic can be used (other choices may be erythromycin or clindamycin).

If you are healthy and the abscess drains well, you can go home. If you are very ill, cannot swallow, or have complicating medical problems (such as diabetes), you may be admitted to the hospital. Young children, who often need general anesthesia for drainage, frequently require a hospital stay for observation.

Arrange follow-up with your doctor or an ear-nose-throat specialist (otolaryngologist) after treatment for a peritonsillar abscess. Also:

  • If the abscess starts to return, you may need a different antibiotic or further drainage.
  • If you develop excessive bleeding or have trouble breathing or swallowing, seek medical attention immediately.


There is no reliable method for preventing a peritonsillar abscess other than limiting risks: Do not smoke, maintain good dental hygiene, and promptly treat oral infections.

  • If you develop a peritonsillar abscess, you may possibly prevent peritonsillar cellulitis by taking an antibiotic. However, you should be closely monitored for abscess formation and may even be hospitalized.
  • If you are likely to form an abscess (for example, if you have tonsillitis frequently), talk with your doctor about whether you should have your tonsils removed.
  • As with any prescription, you must finish the full course of the antibiotic even if you feel better after a few days.

People with an uncomplicated, well-treated peritonsillar abscess usually recover fully. If you don't have chronic tonsillitis (in which your tonsils regularly become inflamed), the chance of the abscess returning is only 10%, and removing your tonsils is usually not necessary.

Most complications occur in people with diabetes, in people whose immune systems are weakened (such as those with AIDS, transplant recipients on immune-suppressing drugs, or cancer patients), or in those who don't recognize the seriousness of the illness and do not seek medical attention.

Major complications of a peritonsillar abscess include:

  • Airway blockage
  • Bleeding from erosion of the abscess into a major blood vessel
  • Dehydration from difficulty swallowing
  • Infection in the tissues beneath the breastbone
  • Pneumonia
  • Meningitis
  • Sepsis (bacteria in the bloodstream)