A 19-year-old man presents to the university health clinic with a 4-day history of worsening sore throat, fever, and difficulty swallowing. He reports that the pain is now significantly worse on the left side, and he has difficulty opening his mouth fully. His voice sounds muffled, which his roommate describes as sounding like he is "talking with a hot potato in his mouth." On physical examination, the patient is febrile to 101.8°F. There is significant trismus. Oropharyngeal examination reveals an erythematous, fluctuant swelling of the superior aspect of the left tonsillar pillar. The left tonsil is displaced inferomedially, and the uvula is deviated to the right. There is palpable, tender left-sided anterior cervical lymphadenopathy.
Which of the following is the most likely diagnosis?
The correct answer is:
C) Peritonsillar abscess
The patient is presenting with a peritonsillar abscess, which is a collection of pus between the tonsillar capsule and the pharyngeal constrictor muscle. It typically occurs as a complication of acute tonsillitis. The hallmark clinical findings include severe unilateral sore throat, odynophagia, trismus due to irritation of the pterygoid muscles) and a muffled "hot potato" voice. On examination, the classic finding is a bulging of the soft palate with deviation of the uvula toward the contralateral (unaffected) side.
Answer choice A: Epiglottitis, is incorrect. While epiglottitis causes a muffled voice, fever, and drooling, it typically presents with a more acute onset and severe respiratory distress (stridor). Patients often sit in a tripod position. Unlike peritonsillar abscess, the oropharyngeal exam in epiglottitis is usually unremarkable, as the inflammation is localized deeper at the supraglottic structures.
Answer choice B: Infectious mononucleosis, is incorrect. While Epstein-Barr virus (EBV) causes severe pharyngitis and tonsillar enlargement, the swelling is typically bilateral and symmetric. It is associated with significant fatigue, generalized lymphadenopathy, and splenomegaly, and it does not typically cause uvular deviation or trismus unless a secondary peritonsillar abscess develops.
Answer choice D: Retropharyngeal abscess, is incorrect. Retropharyngeal abscess is a deep neck space infection more common in children. While it causes fever and a muffled voice, the swelling is located on the posterior pharyngeal wall rather than the tonsillar pillar. It is also characterized by pain with neck extension rather than trismus and uvular deviation.
Answer choice E: Vincent angina, is incorrect. Also known as "trench mouth" or acute necrotizing ulcerative gingivitis, this is an infection caused by fusiform bacteria and spirochetes. It presents with painful, bleeding gums, punched-out interdental papillae, and halitosis, rather than a localized peritonsillar collection.
Key Learning Point
Peritonsillar abscess is a clinical diagnosis characterized by fever, unilateral sore throat, trismus, and uvular deviation away from the affected side. Treatment involves incision and drainage or needle aspiration followed by a course of antibiotics such as amoxicillin-clavulanate or clindamycin to cover group A Streptococcus and oral anaerobes.
