Clinical Scenario:
A 13-year-old boy is brought to the emergency department after developing sudden weakness of the right side of his body and difficulty speaking. His parents report that he has had intermittent fever, fatigue, and loss of appetite for the past 4 weeks. On examination, he is febrile and has a previously undocumented pansystolic murmur at the apex. Urinalysis reveals 2+ proteinuria and numerous red blood cells, while serum creatinine is normal. Brain CT excludes intracranial hemorrhage.
Which of the following is the most likely diagnosis?
A. Acute rheumatic fever
B. Infective endocarditis
C. Polyarteritis nodosa
D. Systemic lupus erythematosus
E. Tuberculous meningitis
Correct answer & Explanation:
Correct Answer: B. Infective endocarditis
Explanation
This child has several classical features of infective endocarditis (IE) with both embolic and immunological complications.
The important clues include:
- Prolonged fever
- Constitutional symptoms (fatigue and anorexia)
- A new cardiac murmur
- Acute ischemic stroke
- Microscopic hematuria
The stroke is most likely due to septic embolization of a fragment of valvular vegetation to the cerebral circulation. Neurological complications occur in approximately 20–40% of patients with infective endocarditis.
The hematuria is an immunological manifestation caused by immune complex-mediated glomerulonephritis, resulting in glomerular inflammation. Patients may have microscopic hematuria, proteinuria, red cell casts, and occasionally impaired renal function.
The coexistence of an embolic event (stroke) and an immune-mediated renal manifestation (hematuria) in a child with prolonged fever and a new murmur is highly suggestive of infective endocarditis.
Why the other options are incorrect
A. Acute rheumatic fever
Incorrect.
Although acute rheumatic fever may present with fever and carditis, it does not typically cause ischemic stroke due to septic emboli or immune complex glomerulonephritis resulting in hematuria.
C. Polyarteritis nodosa
Incorrect.
Polyarteritis nodosa may cause hypertension, renal disease, and neurological manifestations, but cardiac vegetations and a new murmur are not characteristic features.
D. Systemic lupus erythematosus
Incorrect.
SLE can cause stroke and nephritis with hematuria, but it is much less likely in this scenario. The prolonged fever, new murmur, and embolic phenomenon are more consistent with infective endocarditis. Although Libman-Sacks endocarditis occurs in SLE, it is usually non-infective.
E. Tuberculous meningitis
Incorrect.
Tuberculous meningitis may present with prolonged fever and focal neurological deficits due to cerebral infarction, but it does not explain the new cardiac murmur and immune-mediated hematuria.
Learning Points
- Stroke is one of the most common neurological complications of infective endocarditis and usually results from septic embolization.
- Microscopic hematuria occurs because of immune complex-mediated glomerulonephritis and is considered an immunologic manifestation of infective endocarditis.
- Embolic events, glomerulonephritis, Osler nodes, and Roth spots are classic complications tested in postgraduate examinations.
- The combination of persistent fever, new murmur, embolic stroke, and hematuria should strongly suggest infective endocarditis.
