Last reviewed: 29 Oct 2020
Last updated: 01 Nov 2018



History and exam

Key diagnostic factors

  • fever >38°C
  • rash
  • eschar
  • lymphadenopathy associated with eschar

Risk factors

  • exposure to human body lice
  • exposure to rodents (rats and mice) and their fleas
  • tick bites
  • mite bites (Southeast Asia, Oceania, northern Australia)
  • travel to the tropics
  • exposure to natural vegetation, forests, scrub, bush
  • exposure to cat or dog fleas

Diagnostic investigations

1st investigations to order

  • FBC
  • LFTs
  • serum electrolyte levels
  • C-reactive protein (CRP)
  • serology
  • polymerase chain reaction (PCR)
More 1st investigations to order

Investigations to consider

  • chest x-ray
  • trial of doxycycline therapy
More investigations to consider

Treatment algorithm


Professor of Medicine

Section on Infectious Diseases

Wake Forest University School of Medicine




CAO declares that he has no competing interests.

Professor Christopher A. Ohl would like to gratefully acknowledge Dr Stephen R. Graves, a previous contributor to this topic. SRG is the author of a reference cited in this topic.

Peer reviewersVIEW ALL


Department of Medicine

University of Peradeniya


Sri Lanka


SAMK declares that he has no competing interests.

Professor of Medicine and Pathology

Albert Einstein College of Medicine

New York City



LW's laboratory research programme is supported by NIH (NIAID) grants. He performs infectious diseases consultation at Montefiore (Weiler Hospital).

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