ID board review: part 2

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ID board review part 2

• CNS, fungal, viral, and tick-borne infections
  HIV immunology

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Question 1

• A 35-year-old man is evaluated in the ED 72 hours
  after initiation of clindamycin and quinine
  therapy for peripheral blood smearconfirmed
  babesiosis. The patient showed improvement the
  first 48 hours after treatment, but his condition
  has now begun to deteriorate. Recent travel
  history includes a 1-month trip to Cape Cod,
  Massachusetts, from which he returned to his home
  in New York City 1 week ago.
• On physical examination, temperature is 40.0 C,
  blood pressure is 90/60 mm Hg, and pulse rate is
  110/min. There is conjunctival icterus.
  Lymphadenopathy is absent, and the neck is
  supple. Cardiopulmonary examination is normal.
  Abdominal examination reveals a tender right
  upper quadrant with hepatomegaly.

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Labs

• Hemoglobin 9.2 g/dL
• Platelet count 40,000/µL
• Leukocyte count 2700/µL
• Alanine aminotransferase 874 U/L
• Blood cultures from 72 hours ago negative
• Bilirubin 7.4 mg/dL
• CXR normal

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Which of the following is the most appropriate
treatment at this time?

• A Begin cefepime and vancomycin
• B Begin corticosteroids
• C Begin doxycycline
• D Switch to atovaquone and azithromycin

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C Begin doxycycline

• Babesia is transmitted by Ixodes scapularis ticks
• Ixodes ticks can be doubly and triply infected
  with Babesia, Borrelia burgdorferi, and Anaplasma
  phagocytophilum.
• HGA typically causes fever, headache and myalgias
• HGA (and acute Lyme) treated with doxycycline

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Anaplasmosis
Babesiosis (maltese cross)
P. ovale
P. falciparum (multiple parasites/RBC)
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Question 2

• A 62-year-old man is evaluated in July for a
  24-hour history of fever, myalgia, and a frontal
  headache. He is otherwise healthy and takes no
  medications.
• Recent travel includes a 2-week camping trip to
  the Blue Ridge Mountains of Virginia 11 days ago.
  The patient does not recall a specific insect or
  tick bite.
• On physical examination, the patient appears
  mildly ill. Temperature is 38.7 C (101.6 F),
  blood pressure is 125/65 mm Hg, pulse rate is
  90/min, and respiration rate is 18/min. There is
  no lymphadenopathy or rash. Cardiopulmonary and
  abdominal examinations are normal.

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Labs
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Which of the following is the most appropriate
next step in management?

• A Doxycycline
• B Oseltamivir
• C Postpone treatment pending diagnostic test
  results
• D Vancomycin and ceftriaxone

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A Doxycycline

• Rocky mountain spotted fever (RMSF)
• R. rickettsiae
• Only 15 of patients present with rash
• Early treatment is indicated ? infection can be
  fatal
• Diagnosis typically by serology

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Question 3

• A 24-year-old woman is evaluated for a 6-day
  history of progressively worsening generalized
  malaise, myalgia, frontal headache, and fever in
  addition to a small papule on the back of her
  left thigh. She returned 4 days ago from a
  4-month trip to Botswana. Prior to the trip, she
  was immunized for hepatitis A. She has also been
  taking mefloquine as prophylaxis for malaria.
• On physical examination, temperature is 38.7 C,
  blood pressure is 110/70 mm Hg, and pulse rate is
  66/min. She has a faint, maculopapular
  erythematous eruption on her trunk and a 1/2-cm
  1/2-cm, mildly tender, ulcerating papule on the
  left anterior thigh with an eschar that is
  surrounded by a halo of erythema.
• Several ipsilateral femoral lymph nodes are
  enlarged.

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Labs

• Hemoglobin 12.1 g/dL
• Leukocyte count 4300/µL
• Creatinine 0.9 mg/dL
• Alanine aminotransferase 92 U/L
• Aspartate aminotransferase 94 U/L

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Which of the following is the most likely cause
of this patients illness?

• A Dengue virus
• B Leishmania major
• C Mycobacterium marinum
• D Rickettsia africae
• E Vibrio vulnificus

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D. Rickettsia africae

• African tick bite fever
• Doxycycline for treatment
• L. major ? Typically no systemic symptoms
• Dengue fever ? may have a rash but no eschar
• M. marinum ? waterborne, think aquariums or other
  water exposure
• V. vulnificus ? waterborne (salt water) and
  causes severe illness, think septic shock after
  eating oysters

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Question 4

• A 30-year-old man with a 6-year history of AIDS
  is hospitalized for gradually increasing
  confusion, decreased vision, dysarthria, and
  right hemiparesis of 8 weeks duration. He has
  not visited his internist for more than 2 years.
  His CD4 cell count was 35/µL when last checked 2
  years ago. There is no indication that he is
  currently taking any HIV-related medications.
• On physical examination, he has evidence of
  wasting syndrome. Vital signs are normal.
  Funduscopic examination is normal. Neurologic
  examination discloses right hemiparesis and right
  hemianopia. He scores 18 of 30 on the MiniMental
  State Examination (normal gt24/30). The remainder
  of the examination is normal.

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Imaging

• MRI of the brain with contrast shows five
  bilateral, hypodense, nonenhancing lesions in the
  white matter of the periventricular
  parieto-occipital region with no mass effect.

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Which of the following is the most likely
diagnosis?

• A Cytomegalovirus encephalitis
• B Primary central nervous system lymphoma
• C Progressive multifocal leukoencephalopathy
  (PML)
• D Toxoplasmosis

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C PML

• Demyelinating disease caused by JC virus
• Typically occurs at CD4 count lt50
• No mass effect on imaging
• Treatment is HAART
• CNS lymphoma ? often mass effect
• CMV encephalitis ? usually periventricular
• Toxoplasmosis ? ring enhancing, mass effect

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Question 5

• A 25-year-old pregnant woman at 25 weeks
  gestation undergoes a new-patient evaluation. She
  has recently diagnosed HIV infection and has
  never taken antiretroviral therapy. Her current
  CD4 cell count is 550/µL, and her HIV viral load
  is 20,000 copies/mL. She takes no medications
  except for a daily PNV.
• Physical examination, including vital signs, is
  normal.

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Which of the following is the most appropriate
management of this patient?

• A Initiate antiretroviral therapy when CD4 cell
  count is lt500/µL
• B Initiate zidovudine-lamivudine and efavirenz
  now
• C Initiate zidovudine, lamivudine, and
  lopinavir-ritonavir now
• D Initiate zidovudine therapy at delivery

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C AZT, 3TC, Kaletra

• Pregnancy is an indication for HAART at all CD4
  counts
• With virologic suppression there is very low risk
  of MTCT
• Zidovudine should always be included in regimen
• Efavirenz is teratogenic

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Question 6

• A 36-year-old woman is evaluated for repeated
  episodes of sinusitis. Five years ago, she had a
  prolonged episode of maxillary sinusitis
  requiring treatment with amoxicillin. Since then,
  she has had three episodes of sinusitis and two
  episodes of bacterial pneumonia that have
  responded well to antibiotic therapy. The patient
  is otherwise well.
• On physical examination, vital signs are normal.
  BMI is 26. Pulmonary examination reveals a few
  crackles at the right posterolateral lung base.
  Complete blood count, serum electrolytes, renal
  function tests, and HIV serologies are normal.
• Radiographs of the chest reveal diffuse, right
  lower lobe densities. A CT scan of the head shows
  mucosal thickening in the maxillary, sphenoid,
  and ethmoid sinuses, and a CT scan of the chest
  reveals bronchiectasis and bullous changes in the
  right lower lobe.

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Which of the following is the most appropriate
next diagnostic step?

• A Bone marrow aspirate
• B Bronchoscopy with bronchoalveolar lavage
• C HIV RNA viral load testing
• D Quantitative immunoglobulin assay
• E T-cell subset panel

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D Quantitative immunoglobulin assay

• Typical presentation for common variable
  immunodeficiency (CVID)
• Bronchoscopy ? unlikely to yield cause of
  recurrent sinus infections
• HIV VL ? Not a good history for acute HIV
• Bone marrow ? No hematologic abnormalities

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Question 7

• A 26-year-old man with a history of AIDS is
  evaluated for a sudden widespread eruption of
  skin lesions. His last office visit was 1 year
  ago when his CD4 cell count was 50/µL. At that
  time, Bactrim, azithromycin, and HAART were
  initiated, but the patient discontinued them
  owing to persistent nausea and vomiting and did
  not return for follow-up care until today.
• On physical examination, he appears cachectic.
  Temperature is 38.3 C. Skin findings, which are
  widely disseminated but concentrated on the face,
  scalp, and neck, consist of 2- to 5-mm
  umbilicated papules with surrounding erythema.
• The remainder of the physical examination is
  normal.

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Which of the following is the most likely
diagnosis?

• A Cytomegalovirus infection
• B Disseminated cryptococcal infection
• C Herpes simplex virus infection
• D Mycobacterium avium complex

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B Disseminated cryptococcal infection

• Must have high index of suspicion in HIV patients
• Lesions appear similar to molluscum contagiosum
• CMV and MAI dont usually cause rash
• HSV rash causes vesicles

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Treatment of cryptococcal infection in HIV
infected patients

• CNS disease
• Amphotericin B /- flucytosine
• Pulmonary/disseminated disease
• Mild/moderate fluconazole, itraconazole,
  voriconazole, posaconazole
• Severe Amphotericin B

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Question 8

• A 31-year-old man is evaluated for a 12-day
  history of low-grade fever, pleuritic chest pain,
  and a nonproductive cough. Two weeks ago, the
  patient traveled to Phoenix, Arizona, for 3 days
  to play in a golf tournament. He lives in central
  Pennsylvania. Medical history is noncontributory,
  and he takes no medications.
• On physical examination, temperature is 37.7 C
  (100.0 F). The remaining vital signs are normal.
  Chest examination reveals occasional bibasilar
  crackles.
• The leukocyte count is 7400/µL (7.4 109/L) with
  52 neutrophils, 32 lymphocytes, 10 monocytes,
  and 6 eosinophils. Chest radiographs show
  bilateral small, scattered infiltrates and
  bilateral pleural effusions.
• Thoracentesis is performed and yields 300 mL of
  amber-colored turbid fluid with a leukocyte count
  of 1200/µL (1.2 109/L) with 88 lymphocytes and
  12 neutrophils. Gram stain and acid-fast bacilli
  stain show no organisms.

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Which of the following is the most likely cause
of this patients illness?

• A Blastomyces dermatitidis
• B Coccidioides immitis
• C Cryptococcus neoformans
• D Fusarium oxysporum
• E Histoplasma capsulatum

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Histoplasmosis (Ohio River Valley Fever)
Coccidiodomycosis (San Jauquin River Valley Fever)
Blastomycosis
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Question 9

• A 52-year-old woman is evaluated for a 6-week
  history of generalized malaise and fatigue. She
  received a kidney transplant 15 years ago for
  hypertension-related renal failure. Her current
  medications include CSA and AZA.
• The vital signs and general physical examination
  are normal.
• CBC is normal. The BUN is 56 mg/dL and the serum
  creatinine level is 3.0 mg/dL compared with a
  value 2 months ago of 1.7 mg/dL. UA is
  significant for 19 leukocytes/hpf, no
  erythrocytes, 2 protein, and many squamous and
  renal tubular epithelial cells, some of which
  have intranuclear inclusions.

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Infection with which of following is the most
likely cause of this patients worsening kidney
function?

• A Cytomegalovirus
• B Epstein-Barr virus
• C Human herpesvirus-8
• D Polyomavirus BK virus
• E Polyomavirus JC virus

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D Polyomavirus BK virus

• BKV induced cystitis and nephropathy occur
  post-kidney transplant
• Often hemorrhagic
• CMV doesnt typically cause nephropathy
• EBV doesnt cause nephropathy
• HHV-8 causes Kaposis sarcoma
• JCV causes PML

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Question 10

• A 35-year-old woman is evaluated for chronic,
  nonhealing, painful erosive genital lesions. The
  lesions have been treated with IV acyclovir, 15
  µg/kg three times daily, for 14 days. The patient
  has AIDS with a CD4 cell count of 55/µL. She
  recently began taking HAART and Bactrim daily.
• Physical examination discloses multiple 2- 3-cm
  erosive lesions surrounding the vaginal introitus
  and on the right labia.
• Viral culture is positive for HSV- 2 that is
  resistant to acyclovir.

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Which of the following is the most appropriate
treatment?

• A Famciclovir
• B Foscarnet
• C Penciclovir
• D Valacyclovir

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B Foscarnet

• Foscarnet is the drug of choice for acyclovir
  resistant HSV
• Doesnt require TK mediated phosphorylation
• Primary foscarnet toxicity is nephrotoxicity
• Famciclovir, penciclovir work by same mechanism
  as acyclovir
• Valacyclovir is oral prodrug of acyclovir

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Question 11

• A 57-year-old man is evaluated for a 2-day
  history of fever, severe myalgia, and a frontal
  headache. He denies cough, diarrhea, abdominal
  pain, or urinary tract symptoms. He returned 1
  week ago from a vacation in Puerto Rico. He slept
  in a well-screened room under mosquito netting.
• On physical examination, the patient is
  moderately ill appearing. Temperature is 39.2 C,
  blood pressure is 108/75 mm Hg, pulse rate is
  96/min, and respiration rate is 18/min. There is
  a maculopapular rash on his trunk. The remainder
  of the examination is normal.

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Labs

• Hemoglobin 14.8 g/dL
• Leukocyte count 3700/µL
• Platelet count 99,000/µL
• Creatinine 1.1 mg/dL
• Alanine aminotransferase 84 U/L
• Aspartate aminotransferase 92 U/L
• INR 1.1
• Activated partial thromboplastin time 27s
• Urinalysis normal

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Which of the following is the most likely
diagnosis?

• A Chikungunya
• B Dengue
• C Influenza
• D Malaria
• E Typhoid fever

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B Dengue

• Typical presentation for dengue
• Chikungunya occurs in Asia, Africa
• Influenza not associated with rash,
  thrombocytopenia, LFT abnormalities
• Malaria doesnt occur in Puerto Rico
• Typhoid may present similarly but rash is not as
  prominent or absent