Tickborne Disease - Information for Healthcare Professionals  

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Southern Tick Associated Rash Illness (STARI) 

A rash similar to the rash of Lyme disease has been described in humans following bites of the lone star tick, Amblyomma americanum. The rash may be accompanied by fatigue, fever, headache, muscle and joint pains.
 
This condition has been named Southern Tick-Associated Rash Illness (STARI). The cause of STARI is not known. 

Epidemiology

Patients bitten by lone star ticks will occasionally develop a circular rash similar to the rash of early Lyme disease. The cause of this rash has not been determined.

In the cases of STARI studied to date, the rash and accompanying symptoms have resolved following treatment with an oral antibiotic (doxycycline), but it is unknown whether this medication speeds recovery.

Clinical Description

The rash of STARI is a red, expanding “bull's-eye” lesion that develops around the site of a lone star tick bite. The rash usually appears within 7 days of tick bite and expands to a diameter of 8 centimeters (3 inches) or more. The rash should not be confused with much smaller areas of redness and discomfort that can occur commonly at the site of any tick bite. Patients may also experience fatigue, headache, fever, and muscle pains. The saliva from lone star ticks can be irritating; redness and discomfort at a bite site does not necessarily indicate an infection.

STARI is diagnosed on the basis of symptoms, geographic location, and possibility of tick bite. Because the cause of STARI is unknown, no diagnostic blood tests have been developed.

Treatment

It is not known whether antibiotic treatment is necessary or beneficial for patients with STARI. Nevertheless, because STARI resembles early Lyme disease, physicians will often treat patients with oral antibiotics.

Prevention

Avoiding being bit by a tick is the best prevention for STARI. Antibiotic treatment following a tick bite is not recommended as a means to prevent STARI. There is no evidence this practice is effective, and this may simply delay onset of disease. For more in-depth information about prevention of tickborne disease, please visit our Prevention of Mosquito and Tickborne Disease section. Additional information on tickborne disease can be found at CDC’s Division of Vector-Borne Diseases (DVBD).