Last reviewed: 5 Oct 2024
Last updated: 24 Apr 2024
Summary
Definition
History and exam
Key diagnostic factors
- known recent tick exposure or bite
- triad of fever, rash, and history of tick exposure
- triad of fever, rash, and headache
- fever
- rash
- headache
- nausea/vomiting
- myalgia
- altered mental status
Full details
Other diagnostic factors
- abdominal pain
- residence in or recent exposure to rural area
- diarrhea
- conjunctivitis
- lymphadenopathy
- peripheral edema
- meningismus
- splenomegaly
- hepatomegaly
- jaundice
- seizures
- shock
- coma
Full details
Risk factors
- illness onset in spring or summer
- returned travelers from an endemic area
- recent (within 2 weeks) outdoor exposure
- known antecedent tick bite
- exposure to dogs or pets that spend time outdoors
Full details
Diagnostic tests
1st tests to order
- CBC
- serum electrolytes and blood urea nitrogen
- LFTs
- indirect immunofluorescent antibody
- blood culture
Full details
Tests to consider
- complement fixation
- latex agglutination
- indirect hemagglutination
- microagglutination
- enzyme immunoassay
- lumbar puncture
- convalescent serology
- chest x-ray
- abdominal CT scan
- immunohistochemistry
- polymerase chain reaction
Full details
Treatment algorithm
INITIAL
suspected Rocky Mountain spotted fever
Contributors
Authors
Christopher A. Ohl, MD
Professor of Medicine
Section on Infectious Diseases
Wake Forest 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 Steven C. Buckingham, a previous contributor to this topic. SCB is an author of several references cited in this topic. We were made aware that Dr Steven C. Buckingham is now deceased.
Peer reviewers
Mary Anne Jackson, MD
Chief
Section of Pediatric Infectious Diseases
Children's Mercy Hospital and Clinics
Professor of Pediatrics
University of Missouri-Kansas City School of Medicine
Kansas City
MO
Disclosures
MAJ is an author of several references cited in this topic.
Differentials
- Other rickettsial diseases
- Meningococcemia
- Ehrlichiosis
More DifferentialsGuidelines
- CDC Health information for international travel (the Yellow Book): rickettsial diseases
- Tickborne diseases of the United States: a reference manual for health care providers
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