A 25-year-old presents with severe throat pain, trismus, uvular deviation to the left, and a bulging right peritonsillar area. Peritonsillar abscess (quinsy) is diagnosed. After aspiration/drainage, the patient recovers. What is the MOST COMMON bacteriological agent in peritonsillar abscess and the best long-term preventive strategy?

• A Group A Streptococcus (Streptococcus pyogenes) — most common; interval tonsillectomy (6 weeks after resolution) is recommended after first or second abscess to prevent recurrence ✓
• B Fusobacterium necrophorum — most common; Lemierre's syndrome is a complication requiring long-term anticoagulation
• C Staphylococcus aureus — most common; MRSA prophylaxis with rifampicin is needed long-term
• D Bacteroides fragilis — predominantly anaerobic infection; metronidazole alone for 14 days prevents recurrence

Explanation

Peritonsillar abscess (PTA) is typically a polymicrobial infection, but Group A beta-hemolytic Streptococcus (GAS/Streptococcus pyogenes) is the most common single organism isolated. Fusobacterium necrophorum is increasingly recognized as an important pathogen, especially in young adults, and may cause Lemierre's syndrome (septic thrombophlebitis of the internal jugular vein). Management is aspiration or incision and drainage with concurrent antibiotics. Interval tonsillectomy is recommended after one episode if recurrence risk is high; 'hot' (immediate) tonsillectomy (quinsy tonsillectomy) is performed when drainage fails or patient cannot tolerate aspiration.

Reference: Dhingra Diseases of Ear, Nose and Throat, 7th ed.

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Written and medically reviewed by the StethoPrep medical team.