Southern Tick-Associated Rash Illness -- When a Bull's-Eye Rash Isn't Lyme Disease

Alison Hinckley, PhD


March 25, 2013

Editorial Collaboration

Medscape &

STARI or Lyme Disease?

STARI, sometimes called "Masters' disease," is defined as a circular bull's-eye-type rash that develops after the bite of a lone star tick.[1] Patients with STARI may also experience fatigue, headache, fever, and myalgia. Long-term sequelae have not been reported. The cause of STARI has not been determined; however, numerous studies have shown that the rash is not caused by Borrelia burgdorferi, the bacterium that causes Lyme disease. Although scientists once hypothesized that STARI was caused by the spirochete Borrelia lonestari, further research did not support this idea, either.

Because the cause of STARI remains unknown, diagnostic blood tests are not available. Although acute STARI tends to be milder than early Lyme disease, the clinical features, including the erythema migrans-like rash, are not readily distinguished from those of early Lyme disease (Figure 2). In the cases of STARI studied to date, the rash and other symptoms have resolved following treatment with oral doxycycline, but it is unclear whether this medication speeds recovery.

Figure 2. STARI rashes. Photographs courtesy of CDC.