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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.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.


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.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


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.
Farlex Partner Medical Dictionary © Farlex 2012


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
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


Bacterial infection with Rickettsia akari, which is spread by mites from a reservoir in mice; a benign, self-limited febrile illness.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


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.
Medical Eponyms © Farlex 2012
References in periodicals archive ?
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.
Our report of these 2 human rickettsialpox cases in Mexico provides a new rickettsial infection to consider in the differential diagnosis of febrile illnesses.
(2.) Paddock CD, Koss T, Eremeeva ME, Dasch GA, Zaki SR, Sumner JW.Isolation of Rickettsia akari from eschars of patients with rickettsialpox. Am J Trop Med Hyg.
Hepatitis in association with rickettsialpox. Vector Borne Zoonotic Dis.
A diagnosis of rickettsialpox was made and doxycycline treatment (200 mg/kg) was initiated.
In summary, we present a case in which the presence of an eschar on the patient's penis, the failure of lesions to appear in crops, the sparsity of lesions, and mice on the family's farm led to a diagnosis of rickettsialpox, which was confirmed by cross-adsorption serologic findings.
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).
This patient's illness was typical of rickettsialpox. He had a classic eschar, and his vesicular rash, severe headache, and thrombocytopenia are characteristic findings of infection with R.
Rickettsialpox may have occurred sporadically in North Carolina in the past, but the incidence of this disease in this state is probably extremely low.