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Last reviewed: 16 Mar 2025
Last updated: 09 Jun 2023

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • fever
  • lymphadenopathy
  • painful skin ulcer
  • unilateral conjunctivitis

Other diagnostic factors

  • headache
  • malaise/fatigue
  • myalgia
  • anorexia
  • abdominal pain
  • vomiting
  • rales
  • non-productive cough/dyspnoea
  • sore throat
  • photophobia
  • vision impairment/loss
  • jaundice, hepatosplenomegaly, diarrhoea
  • positive Kernig's/Brudzinski's sign, stiff neck

Risk factors

  • tick exposure
  • biting fly exposure
  • contact with infected animals
  • outdoor work in areas where infected animals live
  • spring or summer season

Diagnostic investigations

1st investigations to order

  • FBC
  • serum electrolyte levels
  • LFTs
  • serum creatine kinase
  • urine dipstick for blood
  • erythrocyte sedimentation rate
  • serology
  • blood culture
  • specimen culture
  • polymerase chain reaction (PCR) of ulcer swab or lymph node aspirate

Investigations to consider

  • chest x-ray
  • lumbar puncture
  • histopathology

Emerging tests

  • antigen detection in urine

Treatment algorithm

Contributors

Authors

William A. Petri, Jr., MD, PhD, FACP
William A. Petri, Jr.

Wade Hampton Frost Professor of Epidemiology

Professor of Medicine, Microbiology, and Pathology

Chief, Division of Infectious Diseases and International Health

University of Virginia

Charlottesville

VA

Disclosures

WAP declares that he has no competing interests.

Peer reviewers

Christopher Huston, MD

Assistant Professor of Medicine

Division of Infectious Diseases

University of Vermont College of Medicine

Burlington

VT

Disclosures

CH declares that he has no competing interests.

Beth Kirkpatrick, MD

Assistant Professor

Infectious Diseases

University of Vermont College of Medicine

Burlington

VT

Disclosures

BK declares that she has no competing interests.

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