Summary
Definition
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
- CRP
- serology
- polymerase chain reaction (PCR)
Investigations to consider
- chest x-ray
- trial of doxycycline therapy
- cell cultures
- immunohistochemistry
Treatment algorithm
suspected or confirmed rickettsial infection: non-allergic to doxycycline: not pregnant or breastfeeding
suspected or confirmed rickettsial infection: doxycycline allergy: not pregnant or breastfeeding
suspected or confirmed rickettsial infection: pregnant or breastfeeding
Contributors
Authors
Christopher A. Ohl, MD
Professor of Medicine
Section on Infectious Diseases
Wake Forest University School of Medicine
Winston-Salem
NC
Disclosures
CAO declares that he has no competing interests.
Acknowledgements
Professor Christopher A. Ohl would like to gratefully acknowledge Dr Stephen R. Graves, a previous contributor to this topic.
Disclosures
SRG is the author of a reference cited in this topic.
Peer reviewers
S.A.M. Kularatne, MD, FRCP (Lond)
Professor
Department of Medicine
University of Peradeniya
Peradeniya
Sri Lanka
Disclosures
SAMK declares that he has no competing interests.
Louis Weiss, MD, MPH
Professor of Medicine and Pathology
Albert Einstein College of Medicine
New York City
NY
Disclosures
LW's laboratory research programme is supported by NIH (NIAID) grants. He performs infectious diseases consultation at Montefiore (Weiler Hospital).
Differentials
- Malaria infection
- Dengue fever
- Chikungunya virus infection
More DifferentialsGuidelines
- CDC health information for international travel (the Yellow Book): rickettsial diseases (including spotted fever & typhus fever rickettsioses, scrub typhus, anaplasmosis, and ehrlichioses)
- Communicable disease control manual: rickettsial diseases and Q fever
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