ENT · Infectious Disease

Peritonsillar Abscess

USMLE2PANCE
7

Bets

The facts most likely to be tested

1

The classic clinical presentation includes severe unilateral throat pain, fever, and the hallmark hot potato voice (muffled voice).

Confidence:
2

Physical examination reveals a deviated uvula away from the side of the abscess and trismus (inability to open the mouth fully).

Confidence:
3

The most common causative pathogens are polymicrobial, primarily Streptococcus pyogenes (Group A Strep) and anaerobic bacteria.

Confidence:
4

The diagnosis is primarily clinical, but a CT scan with contrast of the neck is the gold standard to differentiate an abscess from peritonsillar cellulitis.

Confidence:
5

Definitive management requires needle aspiration or incision and drainage (I&D) in conjunction with intravenous antibiotics.

Confidence:
6

Empiric antibiotic therapy must cover both aerobic and anaerobic organisms, typically with ampicillin-sulbactam or clindamycin.

Confidence:
7

Patients with recurrent episodes or those who fail initial drainage may require an urgent tonsillectomy.

Confidence:

Vignette unlocked

A 22-year-old male presents to the emergency department with a 3-day history of worsening sore throat, difficulty swallowing, and drooling. On physical exam, he has a muffled 'hot potato' voice and significant trismus. Examination of the oropharynx reveals a swollen, erythematous left tonsil with the uvula deviated to the right. He is febrile at 101.4°F (38.6°C).

What is the most appropriate next step in management?

+Reveal answer

Needle aspiration or incision and drainage (I&D) of the abscess

The patient presents with the classic triad of peritonsillar abscess (trismus, uvula deviation, and hot potato voice); the definitive treatment is surgical drainage of the purulent collection.

Mo

Depth

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Etiology / Epidemiology

Common in adolescents/young adults following untreated streptococcal pharyngitis.

Clinical Manifestations

Presents with hot potato voice, trismus, and uvular deviation to the contralateral side.

Diagnosis

Clinical diagnosis; CT scan with contrast is the gold standard for confirming abscess formation.

Treatment

Requires needle aspiration or incision and drainage plus amoxicillin/clavulanate.

Prognosis

High cure rate with drainage; airway obstruction is the primary life-threatening complication.

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Epidemiology & Etiology

Most common deep neck infection in adults, typically arising as a complication of tonsillitis. Polymicrobial infection is standard, with Streptococcus pyogenes (Group A Strep) being the most frequent pathogen. Smoking and periodontal disease are significant risk factors.

Pertinent Anatomy

The abscess forms in the potential space between the tonsillar capsule and the pharyngeal constrictor muscle. This location explains the proximity to the pterygoid muscles, leading to the classic symptom of trismus.

Pathophysiology

Infection begins as peritonsillitis, progressing to cellulitis and eventually a localized collection of pus. The inflammatory process causes significant edema of the soft palate and uvula. If left untreated, the infection can track inferiorly into the parapharyngeal space.

Clinical Manifestations

Patients present with severe unilateral throat pain, hot potato voice, and trismus (inability to open the mouth). Physical exam reveals a deviated uvula and a bulging, erythematous tonsillar pillar. Airway compromise, drooling, and respiratory distress are emergency red flags requiring immediate intervention.

Diagnosis

Diagnosis is primarily clinical based on the physical exam. A CT scan with contrast is the gold standard to differentiate between cellulitis and a discrete abscess. Imaging is indicated if the diagnosis is unclear or if deep neck space involvement is suspected.

Treatment

Management requires needle aspiration or incision and drainage (I&D) to evacuate the purulence. Amoxicillin/clavulanate is the first-line antibiotic to cover both aerobic and anaerobic flora. Clindamycin is the alternative for penicillin-allergic patients. Steroids may be used to reduce edema, but airway monitoring is mandatory.

Prognosis

Most patients recover fully with drainage and antibiotics. Recurrence occurs in approximately 10% of patients, often necessitating an elective tonsillectomy.

Differential Diagnosis

Epiglottitis: presents with drooling and tripod positioning without tonsillar bulging

Retropharyngeal abscess: involves posterior pharyngeal wall swelling and neck stiffness

Tonsillitis: lacks the localized fluctuant mass and trismus

Ludwig's angina: involves bilateral submandibular/sublingual space swelling

Mononucleosis: presents with bilateral tonsillar hypertrophy and posterior cervical lymphadenopathy