PassFinals
ENT

Peritonsillar abscess

A collection of pus between the tonsil capsule and the pharyngeal muscles (quinsy), forming when tonsillitis spreads beyond the tonsil into an adjacent tissue plane, producing trismus and a muffled voice that mark it out as a surgical emergency rather than severe tonsillitis.

In a nutshell

Quinsy is a peritonsillar pus collection causing severe unilateral throat pain, trismus, muffled voice, drooling and asymmetric swelling. It is a severe suppurative throat complication: assess the airway, refer urgently to ENT and provide source control with antibiotics.

Classic presentation

Worsening unilateral sore throat with trismus, muffled voice, drooling and asymmetric peritonsillar or soft-palate swelling, often with uvular deviation.

Key points

  • Quinsy is a suppurative complication beyond the tonsil, not just severe tonsillitis.
  • Trismus, muffled voice, drooling and unilateral swelling are high-yield clues, but airway assessment always comes first.
  • Needle aspiration or incision and drainage provides source control; antibiotics alone are not a reliable substitute for ENT assessment.
  • Give antimicrobial treatment alongside drainage, using local microbiology guidance and the BNF, with IV treatment when severe or unable to swallow.
  • Stridor, respiratory distress, inability to handle secretions, neck swelling, sepsis or chest symptoms require emergency multidisciplinary escalation.
  • Use CT selectively when the examination is limited or deep-neck or mediastinal spread is suspected; do not delay airway care.
  • Recurrent quinsy or recurrent disabling tonsillitis warrants ENT follow-up and an individualised tonsillectomy discussion.

First-line investigation

Airway-focused clinical examination; ENT-led aspiration may confirm and decompress a collection, with contrast CT reserved for uncertainty or suspected deep-neck spread.

Management

Assess the airway and sepsis risk

  • Escalate immediately for stridor, respiratory distress, inability to handle secretions, rapidly progressive swelling or severe systemic illness, involving ENT, anaesthetics and critical-care teams early.1,2

Arrange urgent ENT source control

  • Refer suspected quinsy urgently for specialist assessment and drainage by needle aspiration or incision and drainage when a collection is present; antibiotics alone are not reliable source control.1,2,3

Support swallowing and hydration

  • Provide appropriate analgesia, fluids and antiemetic treatment; admit when oral intake is inadequate, sepsis or airway observation is required, or pain remains uncontrolled.1,4

Treat infection and investigate deep spread

  • Give local-guideline antimicrobial cover for streptococci and anaerobes alongside drainage; use contrast CT selectively for uncertain diagnosis, limited examination or suspected parapharyngeal, retropharyngeal, vascular or mediastinal extension.3,2,4

Prevent recurrence and reassess

  • Arrange ENT follow-up for recurrent quinsy, recurrent disabling tonsillitis, persistent unilateral symptoms or malignancy concerns; tonsillectomy is individualised rather than automatic after one uncomplicated episode.5,2

Exam traps

  • Trismus and unilateral swelling need urgent ENT assessment, not simple community oral antibiotics alone.
  • A muffled voice and drooling signal oropharyngeal dysfunction; always check the airway and ability to handle secretions.
  • A dry aspiration does not automatically exclude a collection or deep-neck infection: reassess and image selectively.
  • Severe trismus limiting examination is a reason for specialist assessment, not dismissal as non-cooperation.

Illustrations

Peritonsillar abscess with uvular deviationClinical photograph of asymmetric tonsillar swelling with contralateral uvular deviation typical of quinsy.James Heilman,MD, Wikimedia Commons · CC-BY-SA-3.0
Anatomy of the peritonsillar spaceDiagram showing the tonsil, its capsule and the adjacent peritonsillar space and pterygoid muscles relevant to trismus.PassFinals · original
Peritonsillar abscess on CTAxial CT of the neck showing a peritonsillar abscess.James Heilman, MD, Wikimedia Commons · CC-BY-SA-4.0

Key sources

  1. NICE NG84: Sore throat (acute): antimicrobial prescribing (Current UK recommendations for hospital referral of quinsy and other suppurative complications, self-care, antibiotics and safety-netting; links updated November 2025.)
  2. Oxford University Hospitals: Pharyngitis/tonsillitis including peritonsillar abscess (NHS hospital antimicrobial guidance for urgent ENT assessment and source control of suspected peritonsillar abscess; reviewed May 2025.)
  3. NHS Lothian: Peritonsillar abscess/quinsy antimicrobial guidance (NHS antimicrobial guidance for post-drainage treatment, microbiology sampling and IV-to-oral decisions; follow local policy and microbiology advice.)
  4. BNF online: antibacterial, analgesic and fluid-prescribing cross-check (Current UK prescribing, contraindication, interaction, renal and pregnancy cross-check; consult live monographs and local microbiology policy before prescribing.)
  5. NHS pathway: Tonsillitis and tonsillectomy (NHS pathway noting recent peritonsillar abscess as a reason for ENT tonsillectomy assessment alongside recurrent or disabling tonsillitis; pathway published February 2024.)

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.