Internal Medicine Exam Common Infectious Diseases 4 — Questions and Answers
Question 1: A 70-year-old nursing home resident presents with confusion, fever, and new urinary incontinence. Urinalysis shows > 100,000 CFU/mL of E. coli. What is the appropriate management?
- Treat with antibiotics immediately given symptomatic bacteriuria (Correct answer)
- Observe without treatment as bacteriuria in elderly is common
- Start antibiotics only if blood cultures are positive
- Repeat urinalysis in 48 hours before deciding
Correct answer: Treat with antibiotics immediately given symptomatic bacteriuria
Symptomatic UTI with systemic signs (confusion, fever) in an elderly patient warrants antibiotic treatment, as opposed to asymptomatic bacteriuria which does not.
Question 2: A 55-year-old diabetic patient develops painless black eschar on the nasal turbinates with orbital swelling and vision changes after DKA. Which organism is responsible?
- Aspergillus fumigatus
- Candida albicans
- Mucor/Rhizopus species (Correct answer)
- Cryptococcus neoformans
Correct answer: Mucor/Rhizopus species
Rhinocerebral mucormycosis is caused by Mucor/Rhizopus species and classically presents in diabetics during DKA, causing angioinvasion with characteristic black necrotic eschar.
Question 3: Which of the following is the most appropriate empiric regimen for a patient with severe community-acquired pneumonia admitted to the ICU?
- Azithromycin monotherapy
- Beta-lactam plus macrolide or respiratory fluoroquinolone (Correct answer)
- Vancomycin plus piperacillin-tazobactam
- Doxycycline alone
Correct answer: Beta-lactam plus macrolide or respiratory fluoroquinolone
Severe CAP requiring ICU admission should be treated with a beta-lactam (e.g., ceftriaxone) combined with either a macrolide or respiratory fluoroquinolone per IDSA/ATS guidelines.
Question 4: A patient is diagnosed with pulmonary tuberculosis. Which drug in the standard RIPE regimen is associated with optic neuritis as a dose-dependent side effect?
- Rifampin
- Isoniazid
- Pyrazinamide
- Ethambutol (Correct answer)
Correct answer: Ethambutol
Ethambutol causes dose-dependent optic neuritis presenting with decreased visual acuity and loss of red-green color discrimination; baseline visual testing is required.
Question 5: A 30-year-old man presents with urethral discharge and dysuria. Gram stain shows gram-negative intracellular diplococci. In addition to treating gonorrhea, empiric treatment for which co-infection is mandatory?
- Syphilis
- Chlamydia trachomatis (Correct answer)
- Trichomonas vaginalis
- Herpes simplex virus
Correct answer: Chlamydia trachomatis
Co-infection with Chlamydia trachomatis is so common with gonorrhea that dual therapy (ceftriaxone + doxycycline or azithromycin) is always recommended.
Question 6: Which finding on echocardiogram is most consistent with infective endocarditis?
- Pericardial effusion
- Oscillating intracardiac mass (vegetation) on a valve (Correct answer)
- Left ventricular hypertrophy
- Mitral valve prolapse without regurgitation
Correct answer: Oscillating intracardiac mass (vegetation) on a valve
An oscillating intracardiac mass (vegetation) on a valve or implanted material is the hallmark echocardiographic finding in infective endocarditis per Duke criteria.
Question 7: A 25-year-old sexually active woman presents with right upper quadrant pain, fever, and cervical motion tenderness. Liver enzymes are mildly elevated. Which diagnosis best explains all findings?
- Acute cholecystitis
- Fitz-Hugh-Curtis syndrome (Correct answer)
- Hepatitis A
- Budd-Chiari syndrome
Correct answer: Fitz-Hugh-Curtis syndrome
Fitz-Hugh-Curtis syndrome is perihepatitis occurring as a complication of pelvic inflammatory disease (typically chlamydia or gonorrhea), causing RUQ pain with perihepatic inflammation.
Internal Medicine Exam Common Infectious Diseases 4
A 70-year-old nursing home resident presents with confusion, fever, and new urinary incontinence.
Urinalysis shows > 100,000 CFU/mL of E. coli.
What is the appropriate management?