Last updated: 03 Feb Doxycycline is the drug of choice for treatment in all patients. Risk factors exposure to human body lice exposure to rodents rats and mice and their fleas tick bites mite bites Southeast Asia, Oceania, northern Australia travel to the tropics exposure to natural vegetation, forests, scrub, bush exposure to cat or dog fleas More risk factors. Investigations to consider chest x-ray trial of doxycycline therapy cell cultures immunohistochemistry More investigations to consider.
Christopher A. Acknowledgements Professor Christopher A. Disclosures SRG is the author of a reference cited in this topic. Differentials Malaria infection Dengue fever Chikungunya virus infection More differentials. I have some feedback on: Feedback on: This page The website in general Something else. I have some feedback on:. Submit Feedback. Ehrlichiosis and anaplasmosis are tickborne infections most commonly reported in the United States, but pathogenic species can be found in many regions of the world.
A variety of species are implicated in infection, but E. Infections with various Ehrlichia and Anaplasma spp. Neoehrlichia mikurensis is a tickborne pathogen that occurs in many parts of Europe and Asia. It generally infects older or immunocompromised people. Sennetsu fever, caused by Neorickettsia sennetsu , occurs in Japan, Malaysia, and possibly other parts of Asia. This disease can be contracted from eating raw fish infected with neorickettsiae-infected flukes.
Rickettsial diseases are difficult to diagnose, even by health care providers experienced with these diseases. Prompt treatment is essential and results in improved outcomes. Clinical presentations vary with the causative agent and patient; however, common symptoms that typically develop within 1—2 weeks of infection include fever, headache, malaise, rash, nausea, or vomiting. African tick-bite fever is typically milder than some other rickettsioses, and recovery is improved with treatment.
It should be suspected in a patient who presents with fever, headache, myalgia, and an eschar tache noir after recent travel to southern Africa. Mediterranean spotted fever is a potentially life-threatening rickettsial infection and should be suspected in patients with fever, rash, and eschar after recent travel to northern Africa or the Mediterranean basin.
Rocky Mountain spotted fever is characterized by fever, headache, nausea, and abdominal pain. Patients with murine or epidemic typhus usually present with a severe but nonspecific febrile illness, and approximately half present with a rash.
Scrub typhus should be suspected in patients with a fever, headache, and myalgia after recent travel to Asia. Eschar, lymphadenopathy, cough, and encephalitis may be present. Ehrlichiosis and anaplasmosis should be suspected in febrile patients with leukopenia with an exposure history. The clinical signs are similar to those of the rickettsioses. Diagnosis is usually based on clinical recognition, epidemiologic context, and serologic testing.
Because of cross-reactivity of antigens, some antibodies may react in group-targeted serologic tests and provide evidence of exposure to the group level. PCR assays and immunohistochemical analyses may also be helpful, but useful results are highly dependent upon the type and timing of specimen submitted.
If an eschar is present, a swab or biopsy sample of the lesion can be evaluated by PCR and provides a species-specific diagnosis. If ehrlichiosis or anaplasmosis is suspected, PCR of a whole blood specimen provides the best diagnostic test. A buffy coat may provide presumptive evidence of infection if examined to identify characteristic intraleukocytic morulae. Ehrlichiosis, anaplasmosis, and spotted fever rickettsiosis are nationally notifiable diseases in the United States.
Commercial laboratories offer rickettsial testing for rickettsioses, anaplasmosis, ehrlichiosis, and scrub typhus. Treatment of patients with possible rickettsioses should begin when the disease is suspected and while awaiting confirmatory testing, as certain infections can be rapidly progressive and fatal. Immediate empiric treatment with a tetracycline is recommended for all ages, most commonly doxycycline.
Chloramphenicol may be an alternative in some cases, but its use is associated with increased risk of death, particularly from R. In some areas, tetracycline-resistant scrub typhus has been reported, and azithromycin may be an effective alternative. Limited clinical experience has shown that A. Expert advice should be sought if alternative agents are being considered.
No vaccine is available for preventing rickettsial infections. Antibiotics are not recommended for prophylaxis of rickettsial diseases and should not be given to asymptomatic people. Travelers should be instructed to minimize exposure to infectious arthropods during travel including lice, fleas, ticks, mites and to animal reservoirs particularly dogs when traveling in endemic areas.
The proper use of insect or tick repellents on skin or clothing, self-examination after visits to vector-infested areas, and wearing protective clothing are ways to reduce risk. Complications are uncommon for most rickettsial diseases, especially if diagnosed early and appropriate treatment initiated promptly. Rickettsialpox is a self-limiting disease and has no complications. Complications that may occur in some rickettsial diseases include:. See smartphone apps to check your skin.
See the DermNet NZ bookstore. DermNet NZ does not provide an online consultation service. If you have any concerns with your skin or its treatment, see a dermatologist for advice. Rickettsial diseases — codes and concepts open. Bacterial infection. Spotted fever group rickettsial diseases, Typhus group rickettsial diseases, Scrub typhus, Rocky mountain spotted fever, Rickettsialpox, Boutonneuse fever, Louse-borne typhus, Murine typhus, Tsutsugamushi disease, Serology in rickettsial diseases, Complications of rickettsial diseases, Treatment of rickettsial diseases.
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