A peritonsillar abscess (PA), often called quinsy, is a serious collection of pus that develops in the tissues located just behind one of the tonsils. This condition is typically a complication of an unaddressed or inadequately treated episode of tonsillitis or pharyngitis, making it an ear, nose, and throat emergency. The abscess itself, being a localized pocket of infected material, is not contagious. However, the bacterial infection that leads to its formation is highly transmissible.
The Difference Between Abscess and Infection Contagion
The peritonsillar abscess itself is a localized complication, meaning it is a discrete consequence of a prior infection that has spread into the surrounding tissue. An abscess is essentially a walled-off pocket of pus containing dead white blood cells, bacteria, and tissue debris. This physical containment is why the abscess itself cannot be transmitted or “caught” by another person.
The danger of transmission lies entirely with the underlying bacterial infection, which is usually Group A Streptococcus, the cause of Strep throat. This bacterium, along with other oral flora, is spread through respiratory droplets released when an infected person coughs, sneezes, or talks. When this precursor infection is passed to another individual, they are at risk of developing tonsillitis, which could then potentially progress to a peritonsillar abscess if not treated appropriately.
A peritonsillar abscess forms when the initial infection, often tonsillitis, breaks out of the tonsil and invades the loose connective tissue in the peritonsillar space. This progression involves a mixture of aerobic bacteria like Streptococcus and various anaerobic bacteria, creating a polymicrobial infection. The subsequent pus formation is the body’s reaction to this spread, isolating the infection from the rest of the throat.
Recognizing Specific Symptoms
The symptoms of a peritonsillar abscess are typically more severe and distinct than those of standard tonsillitis, often developing within two to five days after the initial sore throat. One of the most telling signs is severe pain focused on only one side of the throat, which differentiates it from the bilateral pain of typical tonsillitis. This unilateral swelling often causes the uvula, the small tissue hanging in the back of the throat, to be displaced away from the affected side.
Another unique symptom is trismus, which is a painful difficulty or inability to fully open the mouth, caused by inflammation of the nearby jaw muscles. Patients also commonly develop a muffled way of speaking, often described as a “hot potato voice,” because the swelling interferes with the normal movement of the soft palate. Difficulty swallowing, known as dysphagia, is often so severe that patients may drool or be unable to swallow their own saliva, leading to dehydration.
Accompanying these localized symptoms are systemic signs of severe infection, including fever, chills, and malaise. Referred ear pain on the same side as the abscess is also common, along with noticeable tenderness and swelling of the lymph nodes in the neck. The presence of unilateral pain combined with trismus or a muffled voice indicates an urgent need for immediate medical attention.
Diagnosis and Medical Intervention
Diagnosing a peritonsillar abscess primarily relies on a thorough clinical examination, where a healthcare provider observes the characteristic unilateral bulging and uvula displacement. In cases where the physical examination is inconclusive or when there is concern about the infection spreading deeper, imaging techniques are employed. Ultrasound or a contrast-enhanced Computed Tomography (CT) scan can be used to precisely differentiate between a fluid-filled abscess and simple peritonsillar cellulitis (inflammation without pus formation).
The most definitive step in both diagnosis and treatment is the drainage of the pus, which is necessary because the abscess will not resolve with antibiotics alone. The gold standard procedure is needle aspiration, where a needle is inserted into the swollen area to withdraw the pus, confirming the diagnosis and providing immediate relief. An alternative method is incision and drainage, where a small cut is made to allow the pus to drain out.
Following drainage, high-dose antibiotics are immediately initiated, often starting intravenously (IV) during a period of hospitalization to ensure rapid systemic coverage. The empiric antibiotic regimen typically targets the common causative organisms, including Group A Streptococcus and oral anaerobic bacteria. Once the patient shows significant symptomatic improvement, they are usually transitioned to an oral antibiotic course, which must be completed to eradicate the infection. In rare instances of recurrent abscesses or in cases where drainage is technically difficult, an acute tonsillectomy—surgical removal of the tonsil—may be considered as a definitive treatment.
Preventing Precursor Infections
Preventing a peritonsillar abscess is centered on managing the initial infections that can lead to its formation, primarily streptococcal pharyngitis or severe tonsillitis. Maintaining rigorous personal hygiene is the first line of defense against the contagious bacterial spread. This involves frequent and thorough hand washing, particularly after coughing or sneezing, and avoiding the sharing of eating utensils or drinks.
Prompt and complete treatment of any suspected case of tonsillitis is a significant preventative measure. If a diagnosis of bacterial tonsillitis is made, it is imperative to take the full course of prescribed antibiotics, even if symptoms begin to improve quickly, to ensure the bacteria is fully eliminated and prevent complication. For individuals who experience frequent, severe episodes of tonsillitis or who have had a peritonsillar abscess before, an elective tonsillectomy may be recommended to remove the primary site of infection. Other risk factors, such as smoking and poor dental hygiene, should also be addressed to reduce the likelihood of this serious complication.