• See Also
  1. Rickettsiae
  • Epidemiology
  1. Uncommon to rare
  2. Outbreaks
    1. Kew Garden Apartments in Queens, New York City (1946)
  • Pathophysiology
  1. Rickettsia Akari
    1. Organism in the spotted fever group
    2. Tiny Gram Negative Cocci
    3. Obligate intracellular Parasites
  2. Transmission
    1. Reservoir: Mice
    2. Mites (Liponyssoides sanguineus) feeds on mice and then transmits to humans via bite
  • Findings
  1. Initial: Arthropod Bite (Mite bite)
    1. Initial small localized erythematous Papule
    2. Vesicle develops at the bite site
    3. Vesicles later crust with a a black crust
  2. Next: Flu-like symptoms
    1. Fever and chills
    2. Headache
    3. Myalgias
    4. Fatigue and generalized weakness
  3. Next
    1. Diffuse, Generalized Rash with vesicular lesions
  • Differential Diagnosis
  1. See Vesiculobullous Rash
  2. Chicken Pox
  • Management
  1. Spontaneously resolves in 2-3 weeks without treatment
    1. Unlike other Rickettsial infections, disease is mild and no mortality in untreated cases
  2. Antibiotics results in prompt resolution
    1. Doxycycline 100 mg orally twice daily for 7 days
    2. Alternatives
      1. Chloramphenicol 500 mg orally or IV four times daily for 7 days
      2. Azithromycin 10 mg/kg/day for 1 dose (for children age <8 years)
  • Prevention
  1. Control of rodent population within home
  • Resources
  1. Rickettsialpox (Wikipedia)
    1. https://en.wikipedia.org/wiki/Rickettsialpox
  • References
  1. Gladwin, Trattler and Mahan (2014) Clinical Microbiology, Medmaster, Fl, p. 117
  2. Krusell (2002) Emerg Infect Dis 8(7):727-8 +PMID: 12095443 [PubMed]