Rocky Mountain spotted fever

Last Updated: 2019-08-27

Author(s): Anzengruber F., Navarini A.

ICD11: -

American rock fever, New World tick bite fever.

Rickettsia rickettsii occurring by Rickettsia rickettsii.

  • Spread all over the world.
  • Especially in the American continent (especially during the spring or summer months).
  • Children between the ages of 4 and 10 are mostly affected.

  • Pathogen: Rickettsia rickettsii, Rickettsia rickettsii is transmitted by tick bites.

  • Incubation period: 2-14 days.
  • In the area of the inoculation site a partly ulcerated, possibly encrusted papule appears.
  • Maculopapular exanthema (initial at wrists and ankles).
  • Nosebleeds, fever, splenohepatomegaly.
  • Kidney, liver and CNS may become involved.

  • Travel medical history
  • Clinic.
  • Lice infestation.
  • Blood count, liver and kidney values, electrolytes.
  • From the 2nd week of illness Weil-Felix reaction (agglutination test).
  • From the 3rd week of the disease, complement fixation reaction. 
  • Indirect immunofluorescence test from the 3rd week of the disease.

Letality: 5-25%.

  • If necessary, intensive medical measures and transfer to the intensive care unit.
  • Control of vital parameters, fluid balance, electrolytes and protein replacement.


    Topical therapy

  • Loxazole Lot. 1% (reapply after 1 and 2 weeks).
  • Permethrin 5% in e.g.: Excipial U Lipolotio.
  • Prioderm® Shampoo (reapply after 1 and 2 weeks).
  • Paranix® Sprax (Dimeticon), application time: 15 min., if necessary repeat after 7 days.
  • Lausweg® foam solution, contact time: 15 min. Repeat after 7 and 14 days.
  • Rausch Laus stop® cream, application time: 20 min., repetition after 7 and 14 days.


    Systemic therapy

  • Doxycycline p.o. 100 mg 2x per day for 8-10 days.
  • Alternative: Ciprofloxacin p.o. 500 mg 2x per day.
  • In pronounced cases intravenously glucocorticoids 100 mg/d for 2-3 days if necessary.

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  2. Elghetany, M.T. and D.H. Walker, Hemostatic Changes in Rocky Mountain Spotted Fever and Mediterranean Spotted Fever. American Journal of Clinical Pathology, 1999. 112(2): p. 159-168.
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  4. Holman, Robert C., et al., Analysis of Risk Factors for Fatal Rocky Mountain Spotted Fever: Evidence for Superiority of Tetracyclines for Therapy. The Journal of Infectious Diseases, 2001. 184(11): p. 1437-1444.
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  7. Ricketts, H.T., A Micro-Organism which Apparently Has a Specific Relationship to Rocky Mountain Spotted Fever. JAMA, 1909. LII(6): p. 491.
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  9. Thorner, A.R., D.H. Walker, and J.W.A. Petri, Rocky Mountain Spotted Fever. Clinical Infectious Diseases, 1998. 27(6): p. 1353-1359.
  10. Walker, D.H., Rickettsia rickettsii and Other Spotted Fever Group Rickettsiae (Rocky Mountain Spotted Fever and Other Spotted Fevers), in Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 2010, Elsevier BV. p. 2499-2507.