Southern Tick Associated Rash Illness
Southern Tick Associated Rash Illness (STARI) occurs after the bite of the Lone Star tick (Amblyomma americanum) and appears to be extremely similar in nature to Lyme disease – however has a few key differences. Borrelia burgdorferi (the causative agent of Lyme disease) has been ruled out as the cause of STARI because Lone Star ticks do not transmit B. burgdorferi. The exact cause of STARI is not known.
The following ticks are known to transmit STARI in humans:
- Lone Star tick (Amblyomma americanum)
Signs + Symptoms
Early STARI symptoms are similar to symptoms of early Lyme disease. A skin lesion (or rash) that looks like a Lyme disease erythema migrans (or bulls-eye) appears at the site of the tick bite. The rash may be accompanied by fatigue, fever, headache, muscle and joint pain.
Treatment with an antibiotic regimen similar to that used for Lyme disease (doxycycline) helps resolve STARI. In some patients, STARI resolves on its own without antibiotic treatment.
Differences between STARI & Lyme Disease
In a study that compared physical findings from STARI patients in with Lyme disease patients (Wormser et al, 2005), several key differences were noted. Sadly, most of these differences are not typically easy for patients to spot, but rather may be seen by a physician, and/or after treatment for Lyme/STARI.
- Patients with STARI were more likely to recall a tick bite than were patients with Lyme disease.
- The time period from tick bite to onset of the skin lesion was shorter among patients with STARI (6 days, on average).
- STARI patients with an erythema migrans rash were less likely to have other symptoms than were Lyme disease patients with erythema migrans rash.
- STARI patients were less likely to have multiple skin lesions, had lesions that were smaller in size than Lyme disease patients (6-10 cm for STARI vs. 6-28 cm for Lyme disease), and had lesions that were more circular in shape and with more central clearing.
- After antibiotic treatment, STARI patients recovered more rapidly than did Lyme disease patients.
The BIG difference between Lyme disease and STARI, is that even though most of the signs and symptoms and even treatment may be the same or very similar, once treated, there does not appear to be any systemic (chronic) effects of STARI as there does with Lyme. Just one treatment of antibiotics has been shown to treat STARI without any long-lasting effects from the disease.