Rickettsia pox

Last Updated: 2019-08-26

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

ICD11: -

Shankmann 1946.

Rickettsiosis caused by Rickettsia acarii.

  • Especially in New York there were several smaller endemic cases.
  • 800 cases were registered by 2010.

  • Rickettsia acarii.
  • Transmission is by mouse and rat mites. R. acarii belongs to the "Spotted fever group.

  • Unspecific early stage (cephalgia, exhaustion).
  • In the course of fever, somnolence: Fever, somnolence.
  • 3-6 days after onset of fever, appearance of roseoles with partially punctiform haemorrhages on the stem, which spread centrifugally. Palmoplantar involvement.
  • Muscle twitching, pressure sensitivity of peripheral nerves, motor restlessness.
  • Hypotension.
  • Bronchitis, conjunctivitis, splenomegaly.
  • Usually lice (pediculosis corporis) can be detected.
  • Facies typhosa: Livid-red face.
  • In the area of the inoculation site a partially ulcerating papulovesicle appears. 

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

Back, forearms, lower legs, ankles.

  • Favorable.
  • Temperatures are declining under antibiotic therapy after 1-2 days.

  1. Paddock, C.D., et al., Rickettsialpox in New York City: a persistent urban zoonosis. Ann N Y Acad Sci, 2003. 990: p. 36-44.
  2. Madison, G., et al., Hepatitis in association with rickettsialpox. Vector Borne Zoonotic Dis, 2008. 8(1): p. 111-5.
  3. Boyd, A.S., Rickettsialpox. Dermatol Clin, 1997. 15(2): p. 313-8.
  4. Heymann, W.R., Rickettsialpox. Clin Dermatol, 1996. 14(3): p. 279-82.
  5. Valbuena, G. and D.H. Walker, Infection of the endothelium by members of the order Rickettsiales. Thromb Haemost, 2009. 102(6): p. 1071-9.