Medical Emergencies · patient case question
Which statement about acute rheumatic fever is true?
Patient case: Two infections, forty-seven years apart
Patient: Two patients
Chief Complaint: A: “I need this tooth out.” B: “My throat has been sore on one side for a month.”
Background: A, 70-year-old male: acute rheumatic fever at age nine following a throat infection. No valve surgery, no previous endocarditis. B, 23-year-old male: non-smoker, minimal alcohol. A painful right tonsillar lesion for four weeks, initially febrile, treated with a full course of broad-spectrum antibiotics without resolution.
Vital Signs: A: BP 138/82 mmHg · HR 76 bpm. B: afebrile now.
Findings: A: non-restorable tooth #19. B: unilateral enlargement of the right tonsil with a firm ulcerated area, and a single firm ipsilateral cervical lymph node. The left tonsil is normal.
Show answer and explanation
Correct answer: C. Antibodies raised against streptococcal antigens cross-react with cardiac and joint tissue
- A. Herpes simplex virus causes primary herpetic gingivostomatitis and recurrent herpes labialis. It has no role in the pathogenesis of rheumatic fever, which is a bacterial sequel.
- B. The organism is STREPTOCOCCUS PYOGENES. Staphylococcus aureus causes a different set of diseases and is not associated with rheumatic fever.
- C. CORRECT. Acute rheumatic fever is a delayed AUTOIMMUNE sequel to pharyngeal infection with GROUP A BETA-HAEMOLYTIC STREPTOCOCCUS. The mechanism is MOLECULAR MIMICRY: antibodies raised against streptococcal M protein cross-react with structurally similar antigens in the patient's own tissues — the endocardium, myocardium and pericardium, and above all the heart VALVES, along with joints, skin and brain. That is why the manifestations are a pancarditis with migratory polyarthritis, chorea, erythema marginatum and subcutaneous nodules, the Jones criteria. The valve damage is what persists.
- D. Asthma has no relationship to rheumatic fever.
Note: ⚠️ The dental consequence, and the error this history invites: a history of rheumatic fever ALONE — and even rheumatic heart disease with established valve damage — does NOT require antibiotic prophylaxis under the 2021 AHA guidance. Rheumatic valve disease was removed from the list in 2007. What DOES require prophylaxis is a PROSTHETIC VALVE, which many of these patients eventually receive, or a previous episode of infective endocarditis. Ask what happened AFTER the rheumatic fever, not merely whether it occurred.
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