Peritonsillar abscess / Quinsy – Clinical presentation and Treatment

A right sided peritonsilar abscess

This article is mainly intedend for use by medical professionals.

Peritonsillar abscess commonly known as Quinsy is localized collections of pus in the peritonsillar space usually occurs as a complication of acute tonsillitis.

Peritonsillar space

  • fibrous capsule of palatine tonsils medially and superior constrictor muscle laterally
  • anterior and posterior tonsillar pillar contribute to anterior and posterior limits, respectively
  • superiorly, this space is related to torus tubarius, while pyriform sinus forms the inferior limit.
  • contains loose connective tissue.


  • Majority of peritonsillar abscess is in young adults between 20 – 40 years.
  • Peritonsillar abscess is rare below five years of age


  • Principal complication of tonsillitis.
  • Recurrent attacks of tonsillitis cause obstruction and obliteration of intra tonsillar clefts and the infection spreads to peritonsillar area causing suppuration.
  • Smoking and chronic periodontal disease could also cause quinsy.
  • Another theory is abscess of Weber’s glands, which are minor salivary glands located in supra tonsillar space.


  • Progressive, usually unilateral, sore throat over 3 – 4days.
  • Marked cervical lymphadenopathy, leading to neck pain
  • Dribbling of saliva, Muffled / Plummy / Hot potato voice.
  • Odynophagia (painful swallowing), dysphagia (difficulty in swallowing) for solids and eventually liquids – This results in poor oral hygiene and oral sepsis-causing halitosis (foul breath).
  • Severe trismus (inability to open mouth) due to inflammation of the pterygoid muscles.
  • Ipsilateral ear ache, fever, lethargy
  • If untreated, spontaneous discharge of pus can occur, or it may spread to parapharyngeal and prevertebral space, causing respiratory distress.
  • In severe cases, airway compromise and inability to swallow.


  • Predominantly unilateral swelling. (bilateral quinsies are seen in Infectious Mononucleosis – IMN)
  • Tonsil pushed downwards and medially
  • Blanches on slight pressure
  • Uvula edematous and pushed to opposite side.
  • Congested pillars, halitosis, trismus, enlarged tender jugulodigastric nodes.
  • Cervical lymphadenopathy, usually jugulodigastric lymph nodes.
  • Torticollis may be seen as the patient keeps the neck tilted on the affected side.

Differential diagnosis

  • Infectious – Peritonsillar cellulitis, Parapharyngeal abscess, Upper third molar abscess, Coexistent IMN.
  • Inflammatory pathologies like Kawasaki presenting as peritonsillar abscess
  • Vascular – Post traumatic pseudoaneurysm of internal carotid artery
  • Benign lesions – Benign lymphoepithelial cyst
  • Neoplastic – Carcinoma of tonsils and pillars, tonsillar lymphoma, Rhabdomyosarcoma, Tumors arising from peritonsillar space, Minor salivary gland tumors.


  • Infection usually starts in the crypta magna of tonsils, from where it spreads beyond the confines of the capsule causing peritonsillitis initially, and peritonsillar abscess later.
  • Another proposed mechanism is necrosis and pus formation in the capsular area, which then obstructs the weber glands, which then swell, and the abscess forms.


  • Group A Beta Hemolytic Streptococci > Strep. Viridans > S.aureus > H. influenza > Anaerobes.


  • Not needed in clear cut cases. Mostly the diagnosis is clinical based on
    • Non-resolving acute tonsillitis with persistent unilateral tonsillar enlargement
    • Unilateral swelling of the peritonsillar area
    • A bulge on the unilateral soft palate with anterior displacement of the ipsilateral tonsil
  • Investigations are recommended only in atypical cases.
    • Needle aspiration of pus
      • Often curative
      • Provides bacteriology
      • Help clarify between peritonsillar abscess and peritonsillar cellulitis.
    • Routine screening for IMN is recommended in peritonsillar abscess patients.
    • Transoral USG
      • Noninvasive method to differentiate PTA from cellulitis.
    • Orthopantomogram – In case of coincidental dental disease
    • Contrast CT of Neck – In case of suspected complications like spread to parapharynx, retropharynx and mediastinum.
    • MRI angiography – In case of suspected vascular anomalies.
  • Supportive Investigations
    • Complete blood count (CBC)
    • Heterophile antibody test (to rule out suspicion of infectious mononucleosis)
    • Elevated CRP in patients with suspected sepsis

Treatment of Peritonsillar abscess

  • Immediate hospital admission and experienced clinical assessment of airway (can precipitate complete airway obstruction)
  • Intravenous (IV) broad spectrum antibiotic with anaerobic coverage + Anti-inflammatory + Antipyretic.
  • IV Benzyl penicillin is the antibiotic of choice. Erythromycin is considered in case of penicillin allergy.
  • A single dose IV steroid in addition to IV antibiotic reduces throat pain, hospital time, fever and trismus.
  • Indications for drainage
    • Obvious pointing abscess
    • Failure to respond to IV antibiotics
    • Evidence of pus in peritonsillar space on imaging.
    • Needle aspiration
      • Relatively pain free, and is not associated with any significant complication.
      • Recurrence rate is 10 – 15%
    • Incision & Drainage
      • Patient in sitting position to prevent aspiration of pus into the larynx.
      • First the oral cavity and throat of the patient is sprayed with 10% topical xylocaine spray to anaesthetize the mucosa.
      • A Saint Claire Thompson quinsy forceps, or a guarded 11 blade can be used to prevent the blade from penetrating the tonsillar substance deeply and damaging underlying vital structures like internal carotid artery.
      • Site of incision – Is commonly over the point of maximum bulge. It can also be made at the junction between a horizontal imaginary line drawn from the base of the uvula to the anterior pillar and a vertical imaginary line drawn along the anterior pillar. After incision a sinus forceps is introduced for complete drainage.
  • Tonsillectomy
    • Some surgeons consider tonsillectomy at time of infection – called as hot tonsillectomy
      • Avoidance of second admission
      • Convalescence from a single episode
      • Avoidance of loss to follow up
      • Rapid relief of symptoms
    • Previously quinsy was considered as an absolute indication for elective interval tonsillectomy – tonsillectomy 6 weeks later after the infection settles.
    • Many now consider a second quinsy as reasonable indication for tonsillectomy.
    • Abscess recurrence is rare after 40 years. Therefore, elective tonsillectomy is not needed in them.

Complications of Peritonsillar abscess

  • Release of large amount of pus into oropharynx – either spontaneous or surgical – can cause aspiration. This can be avoided by prior aspiration of the pus using a wide bore needle under antibiotic coverage.
  • Deep neck space infections and mediastinitis.


Dr. Sanu. P. Moideen, MBBS, MS (ENT), DNB (ENT), FHNOS, is an otolaryngologist (ENT surgeon), head and neck oncosurgeon practising in Muvattupuzha, Kerala, India. After finishing his postgraduate training, he pursued specialist training in paediatric ENT and head and neck oncosurgery from eminent institutions in India and the US.

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