Topic
Review Topic
0
0
Snapshot
  • A 68-year-old man presents to the physician with complaints of fever, malaise, and chills for the past few weeks. He says that he and his wife recently visited New Hampshire for a summer family reunion, where they hiked in the White Mountains. His temperature is 102°F (38.9°C). Physical exam is notable for a palpable spleen. Laboratory studies are significant for a hematocrit of 30%, decreased serum haptoglobin levels, and an elevated reticulocyte count. A peripheral blood smear is obtained, and confirms the diagnosis.
Introduction
  • Epidemiology
    • location
      • northeastern United States (same geography as Lyme disease)
    • risk factors
      • outdoor activities that increase exposure to ticks
  • Pathogenesis
    • transmission
      • Ixodes tick is the vector for the parasite  
        • same vector as Borrelia burgdorferi which causes Lyme disease; co-infection may occur
      • white-footed mouse is a reservoir
  • Associated conditions
    • hemolytic anemia
Presentation
  • Symptoms 
    • fever
      • may be sustained or intermittent
    • chills
    • malaise
    • fatigue
    • arthralgias
    • nausea and vomiting
    • dark urine
  • Physical exam
    • typically few, if any, physical findings
    • in a minority of patients
      • jaundice
      • splenomegaly
      • hepatomegaly
      • petechiae
      • ecchymoses
Studies
  • Labs
    • complete blood count with differential
      • mild-to-severe hemolytic anemia
      • lymphopenia
      • thrombocytopenia
    • decreased serum haptoglobin levels
    • elevated reticulocyte counts
  • Histology
    • peripheral blood smear
      • Giemsa-stained or Wright-stained
        • intraerythrocytic ring forms with a central pallor
        • merozoites arranged in tetrad configuration resembling a Maltese cross (pathognomonic of babesiosis) 
  • Making the diagnosis
    • based on clinical presentation and peripheral blood smear findings
Differential
  • Malaria
    • distinguishing factor
      • visualization of Plasmodium on peripheral blood smear
  • Lyme disease
    • distinguishing factor
      • erythema migrans (bulls-eye rash)
  • Erlichiosis
    • distinguishing factor
      • southeastern and mid-Atlantic United States
Treatment
  • Medical 
    • IV atovaquone and IV azithromycin
    • IV clindamycin and oral quinine
Complications
  • Severe hemolytic anemia
  • Thrombocytopenia
  • Disseminated intravascular coagulation (DIC)
  • Death
    • babesiosis can be severe or life-threatening particularly in the following groups
      • asplenic patients
      • immunocompromised patients
      • elderly
 

Please rate topic.

Average 5.0 of 2 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Topic COMMENTS (0)
Private Note