Merck Manual

Please confirm that you are a health care professional

honeypot link


(Vesicular Rickettsiosis)


William A. Petri, Jr

, MD, PhD, University of Virginia School of Medicine

Last full review/revision Mar 2022
Click here for Patient Education

Rickettsialpox is caused by Rickettsia akari. Symptoms are an initial local lesion and a generalized papulovesicular rash.

Rickettsialpox, a rickettsial disease, occurs in many areas of the US and in Russia, Korea, and Africa. The vector, a small, colorless mite, is widely distributed. It infects the house mouse and some species of wild mice. Humans may be infected by chigger (mite larvae) or adult mite bites.

An eschar appears about 1 week before onset of fever as a small papule 1 to 1.5 cm in diameter, then develops into a small ulcer with a dark crust that leaves a scar when it heals. Regional lymphadenopathy is present. An intermittent fever lasts about 1 week, with chills, profuse sweating, headache, photophobia, and muscle pains. Early in the febrile course, a generalized maculopapular rash with intraepidermal vesicles appears, sparing the palms and soles.

The disease is mild; no deaths have been reported.

Rickettsialpox is a self-limited disease; however, treatment with doxycycline 100 mg orally twice a day for 5 days will shorten the duration of systemic symptoms.

For prophylaxis, mouse harborages must be destroyed, and the vector controlled by residual insecticides.

Drugs Mentioned In This Article

Drug Name Select Trade
Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
quiz link

Test your knowledge

Take a Quiz!