Southern Tick–Associated Rash Illness

lone star tick on green background


Where lone star ticks can be found...

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.


The Centers for Disease Control and Prevention (CDC) is conducting a study to investigate tick bite illnesses that result in erythema migrans-like skin rashes occurring in areas where Lyme disease is uncommon (see list of States below). Examples of erythema migrans-like skin rashes.

This study is ongoing through December 2019.

Patients who are enrolled in this study will be asked to:

  • Visit the participating healthcare provider twice.
  • Provide clinical specimens (skin biopsies, blood, urine and/or tick samples).
  • Complete a questionnaire at each visit.

The clinical specimens and data collected through this study will be used to assist efforts to develop new diagnostic tests for tick-borne diseases and to perform studies that may help identify the cause of Southern Tick-Associated Rash Illness (STARI) in the United States.

If you have been bitten by a tick or have a known exposure to ticks in the last 30 days and developed an expanding skin rash larger than 3 cm across, you may qualify for this study (please see inclusion and exclusion criteria below).  To see if you are eligible to participate, please contact us at tbrstudymailbox@cdc.govPlease provide a phone number and email address so that we may contact you promptly.

List of States: Alabama, Arkansas, Florida, Georgia, Kentucky, Louisiana, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, Tennessee, Texas.

 Additionally, if you know you have been bitten by a tick other than Ixodes scapularis or Ixodes pacificus, and you develop a rash at the bite site, you may be eligible for this study regardless of location.  

Study Inclusion Criteria:

  1. You must be at least 3 years of age.
  2. You must currently have a round, oval, or ring shaped, colored, expanding skin rash that has been confirmed by a healthcare provider to be at least 3 cm across.
  3. Within the last 30 days, you must have had a tick bite at the rash site, or potential exposure to ticks prior to developing the rash.
  4. You must be willing to donate skin, blood, urine, and/or tick samples (if the tick is available).
  5. You must provide written consent/parental permission/assent to collect, test, and store the samples listed above for later testing.

Study Exclusion Criteria:

Patients with one or more of the following as assessed by the collaborating physician are not eligible to enroll:

  1. People currently taking antibiotics for more than 3 days or who have taken antibiotics in the past 30 days (unless you are submitting the tick that bit you).
  2. People who are immunocompromised for any reason (examples include: HIV infection, taking immunosuppressive medicine, undergoing radiation or chemotherapy).