Peritonsillar abscess / Quinsy – Clinical presentation and Treatment

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.

Incidence

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

Etiology

• 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.

Symptoms

• 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.

Signs

• 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.

Pathophysiology

• 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.

Microbiology

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

Investigations

• 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.