What are the symptoms and diagnostic approach for a patient with a history of acute bacterial tonsillitis suspected of having a peritonsillar abscess?

Peritonsillar Abscess: Clinical Presentation and Diagnosis

Peritonsillar abscess presents with a characteristic triad of severe unilateral throat pain, trismus, and "hot potato voice," and diagnosis is primarily clinical based on physical examination findings of unilateral peritonsillar swelling with uvular deviation. 1, 2

Classic Symptoms

The typical presentation includes:

• Severe sore throat that is markedly worse on one side, with progressive worsening despite initial treatment for tonsillitis 1, 2
• Trismus (difficulty opening the mouth) due to inflammation of the pterygoid muscles 1, 3
• "Hot potato voice" (muffled voice quality) reflecting the space-occupying lesion in the oropharynx 1, 2
• Dysphagia (difficulty swallowing) that may progress to inability to swallow saliva 1, 2
• Fever and malaise as systemic manifestations of the infection 1, 2
• Otalgia (referred ear pain) on the affected side 1
• Drooling in severe cases due to difficulty managing oral secretions 4

Physical Examination Findings

The diagnosis is typically made clinically through examination revealing:

• Unilateral peritonsillar swelling with bulging of the soft palate on the affected side 1, 2
• Uvular deviation away from the side of the abscess 5
• Asymmetric tonsils with the affected tonsil displaced medially and anteriorly 6
• Neck tenderness or swelling may be present, indicating potential spread of infection 4

Diagnostic Approach

Diagnosis is primarily clinical and does not require imaging or laboratory confirmation in typical presentations. 2

When Clinical Diagnosis is Sufficient

• Most cases can be diagnosed based on history and physical examination alone 2
• The combination of unilateral peritonsillar swelling, uvular deviation, trismus, and hot potato voice is highly specific 1, 2

When Additional Testing May Be Needed

• Imaging (CT with contrast) should be considered when there is concern for deep neck space extension, such as severe neck swelling or signs suggesting retropharyngeal or parapharyngeal involvement 4
• Blood cultures may be indicated in patients with signs of sepsis (hypotension, tachycardia, altered mental status) 5
• Aspiration or incision and drainage serves both diagnostic and therapeutic purposes, yielding thick pus that confirms the diagnosis 3, 2

Critical Red Flags Requiring Urgent Intervention

Watch for signs of potential airway compromise or serious complications:

• Respiratory distress or stridor indicating impending airway obstruction 5
• Inability to swallow saliva or drooling suggesting severe dysphagia 5
• Severe neck swelling suggesting deep space infection 5
• Signs of sepsis (hypotension, tachycardia, altered mental status) 5
• Bilateral presentation is rare but represents a true emergency with catastrophic potential 3

Special Diagnostic Considerations

Occult Presentation

• Rarely, peritonsillar abscess may present as asymptomatic unilateral tonsillar enlargement without typical acute symptoms 6
• This atypical presentation should be considered in the differential diagnosis of persistent unilateral tonsillar asymmetry 6

Microbiology

• Peritonsillar abscess is a polymicrobial infection with Group A streptococcus as the predominant organism, along with oral anaerobes 1, 2
• Routine culture is not necessary for diagnosis but may guide therapy in treatment failures 7
• Aspirated material should be placed in anaerobic transport if culture is performed 7

Common Pitfalls to Avoid

• Do not delay treatment waiting for imaging or laboratory confirmation in typical presentations 2
• Do not miss bilateral abscesses, which are rare but life-threatening 3
• Do not underestimate the risk of airway obstruction, aspiration, or extension into deep neck tissues 4, 2
• Consider Lemierre syndrome (septic thrombophlebitis of the internal jugular vein) in patients with persistent fever, neck pain/swelling, and signs of sepsis, which carries a 6.4% mortality rate even with treatment 5