Quinsy (Peritonsillar Abscess) Throat Tonsil Abscess

What is a quinsy?

A quinsy is another term for a peritonsillar abscess (PTA). It is a collection of pus in the throat (pharynx) region specifically between the tonsil tissue and the capsule surrounding it. A quinsy progresses from a tonsillitis to cellulitis and eventually an abscess forms. It is a more common infection of the head and throat seen in children and young adults. The abscess is almost always unilateral meaning that is occurs on one side only. Although a quinsy can be treated with antibiotics, surgical procedures for drainage or even a tonsillectomy may be necessary. A quinsy is a serious condition that can have life threatening complications when left untreated. In recent years, it has been more frequently seen in older patients although it still remains an uncommon infection after early adulthood. Drug resistance has contributed to abscesses that have a longer course with more severe symptoms.

How does a quinsy form?

Quinsy Location

The tonsils are lymphoid tissue that lie in the side walls (lateral walls) of the first part of the throat (oropharynx) that connects to the mouth. It is known as the palantine tonsils. Behind these tonsils are the throat muscles like the superior pharyngeal constrictor muscle. Between the tonsils and throat muscles lies a potential space where the pus can accumulate. The capsule of the tonsils is not a true capsule and does fully encapsulate the tonsillar tissue.

Quinsy Pathophysiology

Tonsillitis is a common infection of tissue in the throat. It is mainly caused by bacteria. When recurrent or chronic tonsillitis is left untreated and in severe cases, it can progress to cellulitis and then lead to pus accumulating in the potential space behind the tonsil. This is known as a peritonsillar abscess or quinsy. Inflammation can spread to the soft palate, neighboring parts of the pharynx (throat) and even to the tongue. The infection is not always localized to the tonsils and can easily spread into the retropharyngeal and parapharyngeal spaces.

However, there are cases where a quinsy forms without a prior history of tonsillitis. It is believed that infection of the Weber glands on the soft palate may be the starting point. These are tiny mucoid salivary glands which normally help to clear debris in the area of the tonsils. An infection of these glands can spread and eventually lead to destruction of tissue and pus forms just above the tonsils.

Causes of a Quinsy

A quinsy is the result of a severe infection of the throat, whether of the tonsils or Weber glands on the soft palate. It is due to bacteria. There are several different species of bacteria that may be involved which can be divided into aerobic and anaerobic bacteria. These bacteria are often part of the normal oral flora – the bacteria that normally exist in the mouth in controlled population sizes without causing disease.

Aerobic bacteria

  • Group A beta-hemolytic Streptococcus pyogenes
  • Staphylococcus aureus
  • Alpha-hemolytic streptococci
  • Coagulase-negative staphylococci
  • Streptococcus pneumoniae

Staphylococci and streptococci are the most common aerobic bacteria that causes a peritonsillar abscess.

Anaerobic bacteria

  • Bacteroides species
  • Prevotella species
  • Porphyromonas species
  • Peptostreptococcus species
  • Fusobacterium species

Bacteroides is the main anaerobic pathogen leading to a peritonsillar abscess.

Quinsy Symptoms

Quinsy Picture

Picture from Wikimedia Commons

There are usually symptoms of tonsillopharyngitis (inflamed tonsils and throat) which precede the development of the quinsy. These symptoms along with symptoms of a quinsy includes :

  • Sore throat
  • Difficulty swallowing
  • Painful swallowing
  • Trismus – pain and difficulty when opening mouth
  • Muffled voice, also described as a “hot potato” voice
  • Excessive salivation and drooling
  • Tonsil swelling is more one one side
  • Bad breath (halitosis)
  • Deviated uvula (opposite side from the quinsy)
  • Referred pain to the ear
  • Swollen neck lymph nodes
  • Fever
  • Fatigue
  • Loss of appetite

Diagnosis of Quinsy

The diagnosis of a quinsy can be made following a clinical examination. It is features such as trismus, a “hot potato” voice, greater tonsillar swelling on one side and deviation of the uvula, which are the main signs that differentiate a quinsy from tonsillitis and pharyngitis. Although the tonsils on one side may be more swollen than the other in tonsillitis without it being due to a quinsy, it is the pronounced bulge at the upper part of the tonsil that is usually a sign of a quinsy. If the clinical presentation clearly indicates a quinsy, then no further diagnostic investigation may be needed. Medication for a quinsy can therefore be commenced immediately.

Specific diagnostic investigation that is warranted to confirm the diagnosis if a quinsy is suspected includes :

  • Needle aspiration where pus is withdrawn and sent to the laboratory for testing. A culture will determine the causative bacteria.
  • CT (computed tomography) scan with intravenous contrast dye or ultrasound will assist in visualizing the quinsy.

Quinsy Treatment

A quinsy can be treated with medication with or without drainage of the abscess. Sometimes a tonsillectomy is performed.


Antibiotics should be commenced immediately even if the diagnosis with a needle aspiration or CT scan has not yet confirmed the presence  quinsy. Constant hydration is important although many quinsy patients refuse fluids mainly due to pain when swallowing. Corticosteroids are sometimes used to reduce pain and swelling.

Hospitalization may be necessary for young children in order to administer intravenous (IV) antibiotics and for hydration. Older children and adults may be able adhere to the prescribed oral antibiotic regimen and therefore hospitalization is not necessary. In severe cases where the quinsy is causing airway obstruction or not resolving despite antibiotic use, hospitalization may then be necessary irrespective of the age of the patient.


Drainage of the abscess can be done in two ways :

  • Needle aspiration where an 18 guage needle is inserted into the abscess cavity and the pus drawn out. Sometimes needle aspiration is only done to collect pus to confirm the diagnosis or identify the causative bacteria.
  • Incision and drainage where the abscess is pierced and a cut made to allow the pus to drain. It is a more painful procedure but ensures that more of the pus is removed than may be possible with needle aspiration.

Antibiotics (oral) should be commenced or continued after drainage.

A tonsillectomy, which is the surgical removal of the tonsils, may be considered immediately once the quinsy is diagnosed or conducted about 4 to 6 weeks after the quinsy is treated. Although a tonsillectomy is not necessary as a means of treating a quinsy, it should be considered if :

  • the quinsy is not resolving despite antibiotic therapy and even drainage.
  • there is a history of recurrent tonsillitis.
  • there is a history of previous peritonsillar abscesses.


  1. Pediatric peritonsillar abscess. Medscape Reference
  2. Peritonsillar abscess and cellulitis. Merck Manuals

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