A 30-year-old man comes into the clinic with a 2-week history of fever, cough, and shortness of breath. He reports several episodes of bloody sputum. He is a non-smoker and lives a healthy lifestyle. Past medical history is unremarkable, and he does not take any prescription medications. Vital signs are within normal limits. Physical examination shows a crescendo-decrescendo midsystolic ejection murmur loudest in the right upper sternal border. Transesophageal echocardiogram (TEE) shows a tricuspid valve vegetation. Blood cultures show gram-positive cocci in clusters.
Which of the following most likely predisposed him to his current infection?
The correct answer is:
C) Intravenous drug use
The patient has bacterial endocarditis caused by Staphylococcus epidermidis, a coagulase-negative and catalase-positive cocci. Intravenous drug use is a known risk factor in the cause of right sided infective endocarditis as it introduces pathogens from the skin surface directly into venous circulation. The bloody sputum is caused by septic emboli which break off and enter pulmonary circulation, resulting in pulmonary complications.
Answer choice A: Childhood asthma, is incorrect. Childhood asthma would not result in the cardiac findings in this patient.
Answer choice B: Endoscopy would not create the cardiac findings seen in this patient.
Answer choice D: Pharygneal infection, is incorrect. Pharyngeal infection with Streptococcus pyogenes can predispose an individual to rheumatic fever and rheumatic heart disease which typically affects the mitral and aortic valves.
Answer choice E: Recurrent sinusitis, is incorrect. Recurrent sinusitis would not predispose to the cardiac findings in this patient.
Key Learning Point
Intravenous drug use predisposes to right-sided infective endocarditis.
