Infectious Disease Management Flashcards
7 cards from real Internal Medicine Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Infectious Disease Management flashcards as text
A 55-year-old patient on prolonged broad-spectrum antibiotics develops profuse watery diarrhea. Stool toxin assay is positive for Clostridioides difficile. He has WBC 18,000 and serum creatinine 1.8 mg/dL. What is the appropriate initial treatment?
Answer: Oral vancomycin 125 mg QID
Fidaxomicin or oral vancomycin is preferred over metronidazole for non-severe C. difficile infection; elevated WBC and creatinine indicate non-fulminant disease still treated with oral vancomycin per current IDSA guidelines.
An HIV-positive patient with CD4 count of 150 cells/μL is started on antiretroviral therapy. Two weeks later he develops worsening cervical lymphadenopathy and fever. Lymph node biopsy shows non-caseating granulomas. What is the most likely diagnosis?
Answer: Immune reconstitution inflammatory syndrome (IRIS)
IRIS occurs when recovering immunity mounts an exaggerated response to a previously subclinical infection (here, likely mycobacterial), typically 2–8 weeks after ART initiation.
A 70-year-old nursing home resident presents with altered mental status and dysuria. Urinalysis shows pyuria and bacteriuria. She is afebrile with stable vitals. What is the BEST management?
Answer: No antibiotic treatment; reassess in 48 hours
Asymptomatic bacteriuria in elderly women should not be treated with antibiotics, as treatment does not reduce morbidity and promotes resistance; altered mental status requires workup for other causes.
A patient with infective endocarditis due to methicillin-susceptible Staphylococcus aureus (MSSA) on a native valve is being treated. Which antibiotic provides superior outcomes?
Answer: Nafcillin (or oxacillin)
Anti-staphylococcal penicillins (nafcillin/oxacillin) are superior to vancomycin for MSSA endocarditis due to better bactericidal activity and clinical outcomes.
A 40-year-old cave explorer develops progressive pulmonary infiltrates and mediastinal lymphadenopathy 3 weeks after visiting bat-inhabited caves in Ohio. Serum urine antigen is positive. What is the treatment?
Answer: Itraconazole 200 mg BID
Mild-to-moderate pulmonary histoplasmosis is treated with itraconazole for 6–12 weeks; it is the drug of choice for non-severe Histoplasma capsulatum infection.
Which finding on echocardiogram is an absolute indication for surgical intervention in infective endocarditis regardless of hemodynamic stability?
Answer: Periannular abscess or fistula formation
Periannular abscess or fistula indicates local invasion and structural destruction, which is an absolute surgical indication regardless of hemodynamic status.
A 35-year-old sexually active man presents with painful genital ulcers and tender inguinal lymphadenopathy. Dark-field microscopy is negative. Which diagnosis is most likely and what is the treatment?
Answer: Herpes simplex virus — acyclovir
Painful vesicular/ulcerative lesions with tender lymphadenopathy in a sexually active patient are characteristic of HSV; acyclovir shortens episode duration.