Peritonsillar Abscess

Peritonsillar abscess (from the Latin abscessus peritonsillaris) is a localized collection of pus that forms in the peritonsillar space — between the capsule of the palatine tonsil and the lateral pharyngeal wall. This condition is the most common deep neck infection and typically arises as a complication of acute or chronic tonsillitis.

The abscess is typically unilateral. If not treated promptly, it may lead to severe, life-threatening complications such as airway obstruction, parapharyngeal abscess, sepsis, or mediastinitis.

Aetiology and pathophysiology

The primary cause is a bacterial infection that spreads from the palatine tonsil into adjacent tissues. Pathogenesis is often linked to obstruction of the excretory ducts of minor salivary glands (Weber’s glands), located near the upper pole of the tonsil. This creates a favorable environment for inflammation (peritonsillitis), which may eventually progress to an abscess.

The most common pathogens include Group A β-hemolytic streptococcus (GABHS), often in combination with anaerobic bacteria such as Fusobacterium necrophorum, contributing to the severity of the condition and pronounced systemic toxicity.

Clinical Significance

The clinical manifestations of peritonsillar abscess is highly characteristic, allowing diagnosis to be based on medical history and physical examination.

Key Symptoms and Signs:

• Sharp, unilateral throat pain: The hallmark symptom. Pain is intense, worsens with swallowing, and may radiate to the ear and teeth on the affected side.
• Dysphagia and odynophagia: Difficulty and marked pain during swallowing, often leading to refusal of food and fluids. Saliva may drool from the corner of the mouth.
• Trismus: Moderate spasm of the masticatory muscles, limiting mouth opening.
• Voice changes: Speech becomes muffled, strained, and hypernasal — often described as a “hot potato voice.”
• Systemic symptoms: High-grade fever (38–39 °C), chills, fatigue, headaches.

Pharyngoscopy reveals marked asymmetry of the oropharynx: hyperemia and bulging of the soft palate on the affected side, deviation of the uvula toward the healthy side, and inferomedial displacement of the tonsil.

Surgical intervention is required, accompanied by intensive antibiotic and detoxification therapy. The primary goal is to evacuate pus via incision and drainage or needle aspiration.

Differential Diagnosis

First and foremost, peritonsillar abscess must be differentiated from parapharyngeal abscess. The latter typically presents with more pronounced trismus and swelling along the lateral neck. Other differential diagnoses include Ludwig’s angina (cellulitis of the mouth floor), diphtheria, scarlet fever, and tonsillar neoplasms. Pharyngoscopic findings — especially inflammation localized to the upper pole of the tonsil — are critical for diagnosis. In uncertain cases, ultrasound or computed tomography (CT) may be employed for confirmation.