Rickettsial pox

• Causes, incidence, and risk factors

  Rickettsial pox is caused by the bacteria, Rickettsia akari. It is commonly found in the United States in New York City and other city areas. It also has been seen in South Africa, Korea, and Russia.

  It is spread by the bite of a mite that lives on mice.

• Symptoms

  The disease begins at the site of the mite bite as a painless, firm, red lump (nodule). The nodule develops into a fluid-filled blister that bursts and crusts over. This lump may be large -- almost up to an inch wide.

  Other symptoms include:

  • Discomfort in bright light (photophobia)
  • Fever and chills
  • Muscle pain (myalgia)
  • Rash that looks like chickenpox
  • Sweating (diaphoresis)

  The rash should clear up within a week.

• Signs and tests

  The health care provider will do an examination to look for a rash similar to the one in chickenpox.

  Tests include:

  • Complete blood count (CBC)
  • Tests of blood serum (serologic studies)
• Treatment

  The goal of treatment is to cure the infection. The basic treatment is with the antibiotic doxycycline. Other antibiotics include chloramphenicol and azithromycin.

• Expectations (prognosis)

  Full recovery is expected.

• Complications

  There are usually no complications if the disorder is treated.

• Calling your health care provider

  Call your health care provider if your child has symptoms of rickettsial pox.

• Prevention

  Sanitary measures, especially controlling mice and their parasites, will prevent the spread of rickettsial pox.

• References

  Raoult D, Rickettsia akari (Rickettsialpox). In: Mandell GL, Bennett JE, Dolin R, eds. Principles and Practice of Pediatric Infectious Diseases. 6th ed. Philadelphia, Pa: Elsevier Churchill Livingstone; 2005:chap 185.

Review Date: 8/1/2008

Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.