Ehrlichiosis Clinical Presentation

Updated: Oct 19, 2016
  • Author: Burke A Cunha, MD; Chief Editor: Michael Stuart Bronze, MD  more...
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Clinical manifestations of ehrlichiosis usually begin 5-14 days after the tick bite. Approximately 68% of patients with human monocytic ehrlichiosis (HME) report a tick bite, and 83% of patients have a history of tick exposure in the 4-week period before onset of symptoms. Onset is abrupt or subacute.

The histories for HME, human granulocytic anaplasmosis (HGA), and E ewingii infection are similar and may include the following [1, 2] :

  • Tick bites or exposure (>90%)

  • Fevers (>90%)

  • Headaches (>85%)

  • Malaise (>70%)

  • Myalgias (>70%)

  • Rigors (60%)

  • Nausea (40%)

  • Vomiting (40%)

  • Anorexia (40%)

  • Confusion (20%)

Rash is rare in patients with HME/HGA. Rash is rare but, if present, usually occurs on the trunk, legs, arms, or face and may be macular, maculopapular, and/or petechial.


Physical Examination

Physical findings due to ehrlichiosis are minimal.

Splenomegaly is not uncommon, but some patients develop hepatomegaly. Lymphadenopathy is very uncommon. Patients with severe ehrlichiosis may develop thrombocytopenia.