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Related to rickettsialpox: Q fever




Rickettsialpox is a relatively mild disease caused by a member of the bacterial family called Rickettsia. Rickettsialpox causes rash, fever, chills, heavy sweating, headache, eye pain (especially when exposed to light), weakness, and achy muscles.


Like other members of the family of Rickettsia, the bacteria causing rickettsialpox live in mice. Tiny mites feed on these infected mice, thus acquiring the organism. When these mites feed on humans, the bacteria can be transmitted.
Rickettsialpox occurs mostly within cities. In the United States, the disease has cropped up in such places as New York City, Boston, Philadelphia, Pittsburgh, and Cleveland. It has also been identified in Russia, Korea, and Africa.

Causes and symptoms

The specific bacteria responsible for rickettsialpox is called Rickettsia akari. A person contracts this bacteria through the bite of an infected mite. After a person has been bitten by an infected mite, there is a delay of about 10 days to three weeks prior to the onset of symptoms.
The first symptom is a bump which appears at the site of the original bite. The bump (papule) develops a tiny, fluid-filled head (vesicle). The vesicle sloughs away, leaving a crusty black scab in its place (eschar). In about a week, the patient develops a fever, chills, heavy sweating, headache, eye pain (especially when exposed to light), weakness, and achy muscles. The fever rises and falls over the course of about a weak. A bumpy rash spreads across the body. Each individual papule follows the same progression: papule, then vesicle, then eschar. The rash does not affect the palms of the hands or the soles of the feet.


Most practitioners are able to diagnose rickettsialpox simply on the basis of its rising and falling fever, and its characteristic rash. Occasionally, blood will be drawn and tests performed to demonstrate the presence of antibodies (immune cells directed against specific bacterial agents) which would confirm a diagnosis of rickettsialpox.


Because rickettsialpox is such a mild illness, some practitioners choose to simply treat the symptoms (giving acetaminophen for fever and achiness, pushing fluids to avoid dehydration). Others will give their patients a course of the antibiotic tetracycline, which will shorten the course of the illness to about one to two days.


Prognosis for full recovery from rickettsialpox is excellent. No deaths have ever been reported from this illness, and even the skin rash heals without scarring.


As with all mite- or tick-borne illnesses, prevention includes avoidance of areas known to harbor the insects, and/or careful application of insect repellents. Furthermore, because mice pass the bacteria on to the mites, it is important to keep mice from nesting in or around residences.



Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311. http://www.cdc.gov.

Key terms

Eschar — A crusty, blackish scab.
Papule — A bump on the skin.
Vesicle — A fluid-filled head on a papule.


a febrile disease marked by a vesiculopapular eruption, resembling chickenpox clinically, caused by Rickettsia akari and transmitted by mites. Called also Kew Gardens spotted fever.


Infection with Rickettsia akari, which is spread by mites from a reservoir in house mice; a benign, self-limited process first recognized in 1946 in the Kew Gardens area of New York City; a few limited outbreaks have later been observed elsewhere.


/rick·ett·si·al·pox/ (rĭ-ket´se-al-poks″) a febrile disease with a vesiculopapular eruption, resembling chickenpox clinically, caused by Rickettsia akari.


Etymology: Howard T. Ricketts; ME, pokkes, pustules
a mild, acute infectious disease caused by Rickettsia akari and transmitted from mice to humans by mites (Allodermanyssus sanguineus). It is characterized by an asymptomatic crusted primary lesion, chills, fever, headache, malaise, myalgia, and a rash resembling chickenpox. About 1 week after onset of symptoms, small, discrete, maculopapular lesions appear on any part of the body, but rarely on palms or soles. These lesions become vesicular and dry and form scabs. Eventually the scabs fall off, leaving no scars. Chloramphenicol or tetracycline hastens recovery. Prevention involves the elimination of house mice. Also called Kew Gardens spotted fever. Compare Rocky Mountain spotted fever. See also Rickettsia.


Kew Gardens fever Infectious disease An infection by Rickettsia akari, transmitted from rodents to humans by the hematophagous mouse mite, Liponyssoides sanguineus Clinical Typical eschar over the initial lesion consisting of a nodule followed by a vesicle at the mite bite site → fever, malaise, headache, backache, myalgia, conjunctivitis, sore throat, chest pain, cough, lymphadenopathy, maculopapules, papulovesicules Treatment Tetracycline


Bacterial infection with Rickettsia akari, which is spread by mites from a reservoir in mice; a benign, self-limited febrile illness.


Howard T., U.S. pathologist, 1871-1910.
Rickettsia akari - a species causing human rickettsialpox.
Rickettsia australis - a species causing a spotted fever.
Rickettsia conrii - an African species probably causing boutonneuse fever.
Rickettsia prowazekii - a species causing epidemic typhus.
Rickettsia rickettsii - the agent of Rocky Mountain spotted fever.
Rickettsia sibirica - the agent of Siberian or North Asian tick typhus.
Rickettsia tsutsugamushi - a species causing tsutsugamushi disease and scrub typhus.
Rickettsia typhi - a species causing murine or endemic typhus fever.
rickettsial - pertaining to or caused by rickettsiae.
rickettsialpox - an acute disease caused by Rickettsia akari; transmitted by the mite.
rickettsiosis - infection with rickettsiae.
rickettsiostatic - an agent inhibitory to the growth of Rickettsia.


a febrile disease of humans marked by a vesiculopapular eruption, clinically resembling chickenpox, caused by Rickettsia akari and transmitted from mice by mites. Called also Kew Gardens spotted fever.
References in periodicals archive ?
Lastly, only the Asian and Eurasian Leptotrombidium species of trombiculid larvae (chiggers) can transmit scrub typhus in endemic regions of Asia, Eurasia, and the South Pacific, and only the house-mouse mite can transmit rickettsialpox in both urban and rural dwellings worldwide, including the southern US.
farinae Same Dermanyssidae Rickettsialpox Liponyssoides sanguineus (formerly Allodermanyssus sanguineus) Dermanyssus Poultry workers' gallinae dermatitis of hands Macronyssidae Urticarial papulovesicular Ornithonyssus bacoti to pustular dermatitis O.
Isolation of Rickettsia akari from eschars of patients with rickettsialpox.
A diagnosis of rickettsialpox was made and doxycycline treatment (200 mg/kg) was initiated.
This case indicates that rickettsialpox is an emerging infectious disease in Turkey.
Rickettsialpox in a New York City hospital, 1980 to 1989.
A diagnosis of rickettsialpox was made, and therapy was started with doxycycline and cefazolin.
This pattern of differential reduction in titers is confirmatory for a serologic diagnosis of rickettsialpox (9).
However, not all patients with rickettsialpox have a vesicular rash.
Rickettsialpox may have occurred sporadically in North Carolina in the past, but the incidence of this disease in this state is probably extremely low.