Definition This is the name for an abscess that forms in the space around the tonsils.
What is going on in the body? The tonsils are part of a ring of tissue called Waldeyer's ring at the back of the throat. Waldeyer's ring has several components, including the palatine tonsils. The lingual tonsils are tonsillar tissue at the back of the tongue. The adenoid is the tonsil-like tissue in the back of the nasal cavity. There are also bands of tonsil-like tissue on the back wall of the throat behind the tonsils. Waldeyer's ring tissue secretes antibodies to defend against viruses, bacteria, and other toxins. Because this tissue is involved in the infection-fighting process, it too, can become infected.
The tonsil sits in the tonsillar fossa, which is an oval bed formed by the muscles of the side of the throat. Between the tonsil and the underlying muscle is the peritonsillar space. It contains a loose tissue called fascia and blood vessels supplying the tonsil and lymphatics. Lymphatic vessels connect the lymphatic drainage system of the tonsil to the neck lymphatics, including the neck lymph nodes. This is why the lymph nodes in the upper neck often swell when the tonsils are infected.
A peritonsillar abscess forms when an infection within the tonsil breaks out into the space between the tonsil and the underlying muscle. This infection then forms a gradually enlarging abscess.
What are the signs and symptoms of the condition? Most people with a peritonsillar abscess have a sore throat for a few days that suddenly becomes very severe. It usually involves only one side. It almost never occurs in someone who has had a tonsillectomy. There is a mild to moderate fever and severe throat pain on one side. One of the main symptoms is difficulty opening the mouth. Swallowing can become so painful that the person avoids all eating or drinking and starts to become dehydrated. There may also be significant ear pain on the affected side.
The lymph nodes in the upper part of the neck just below the angle of the jaw may be quite swollen. Since the abscess is between the tonsil and the muscles of the throat, the tonsil is often pushed down and toward the middle of the throat. The uvula, which hangs down from the centre part of the palate, is pushed to the opposite side, and the palate may be red or swollen.
What are the causes and risks of the condition? The main cause is pharyngitis, or sore throat, or tonsillitis. A person who has had peritonsillar abscess or chronic tonsillitis in the past is at a higher risk.
What can be done to prevent the condition? The only real way to prevent the disease is to have the tonsils removed. Even people receiving antibiotics can develop a peritonsillar abscess. Usually it develops after several days of sore throat. Most viral sore throats resolve in 24 to 48 hours. So if a sore throat lasts for more than about two days, one should seek medical attention.
How is the condition diagnosed? It is diagnosed based mostly on physical examination. Sometimes it is hard to tell whether the soft tissues of the palate are very inflamed or an abscess is developing. Placing a needle into the peritonsillar space can sometimes help to show the difference. In rare cases, a CT scan with intravenous dye is needed.
What are the long-term effects of the condition? One of the main concerns is the spread of the infection to nearby areas in the neck. It can spread into the parapharyngeal space. This space houses the carotid artery, the jugular vein and several important nerves. A long-term infection here can weaken the carotid artery and jugular vein, and life-threatening haemorrhage can result.
The infection can also descend into the chest and cause infection in the soft tissue there, which is known as mediastinitis. Pus could also collect around the lungs. If it gets into the prevertebral space, it can descend into the abdomen. Peritonsillar abscess can also cause an infected clot to form in the jugular vein. Small infected clots then spread throughout the body, particularly the lungs.
What are the treatments for the condition? If caught early, the infection usually responds to high-dose antibiotics and corticosteroids. Oral corticosteroids, such as methylprednisolone or prednisone, must be used carefully because they can mask the spread of the infection. Once it has reached the abscess stage, it can be managed in several ways. Some people respond to oral antibiotics, pain relievers, and repeated draining of the abscess with a needle. The most time-honored treatment is to open the abscess and drain it. This is usually done in a doctor's office, but sometimes needs to be done in an operating room. If the person does go to surgery, the tonsils are usually removed. Most people with a first occurrence of the abscess just have it drained. But if there is a history of chronic or recurrent tonsillitis, a tonsillectomy can be done immediately or a few weeks after draining the abscess. Because it can spread to other parts of the body, this kind of infection is not usually cured by antibiotics.
What are the side effects of the treatments? If the abscess is drained with a needle, there are very few side effects. Usually the person feels much better as soon as it is drained. Opening the abscess with a knife also has very few side effects. There may be some temporary bleeding. If the tonsils are removed, excess bleeding occurs about 3% of the time. Draining the abscess usually stops the pain very quickly. After tonsillectomy, a painful throat lasts for seven to 10 days.
What happens after treatment for the condition? If treatment is successful, the symptoms improve rapidly, and the person soon returns to a healthy state.
How is the condition monitored? Any persistent sore throat with difficulty opening the mouth, severe ear pain, and difficulty swallowing must be examined immediately. Any delay can put the person at risk for complications from spread of the infection.
Author: Mark Loury, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request