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Tickborne illness - Explainer

Southern Tick-Associated Rash Illness (STARI)

Southern tick-associated rash illness (STARI) is a rash that can appear after a bite from the lone star tick (Amblyomma americanum). Its hallmark is a red, slowly expanding, sometimes bull's-eye-shaped rash at the bite site, occasionally with mild fatigue, headache, fever, or aches. STARI is not Lyme disease, and its exact cause has not been established. Most people recover, but any rash after a tick bite should be evaluated by a licensed clinician.

Last reviewed: 2026-07-20 · Educational only — not medical advice.

Carried by the Lone Star tick. Spread by: Lone star tick.

What is southern tick-associated rash illness (stari)?

STARI is a rash illness that can follow the bite of a lone star tick. It was first recognized in the southern United States among people who developed a Lyme-like rash but did not have Lyme disease. Its defining feature is a red, circular, expanding rash at the bite site, sometimes accompanied by mild flu-like symptoms. Unlike Lyme disease, STARI has no confirmed cause and no established laboratory test. It is generally considered a mild, self-limited condition, and this page is educational information, not medical advice.

Symptoms

  • A red, expanding circular rash at the bite site, sometimes with central clearing that resembles a bull's-eye or target
  • A rash that typically grows to about 3-12 inches (8-30 cm) across
  • Fatigue
  • Headache
  • Fever
  • Muscle and joint aches

How soon do symptoms appear?

The STARI rash usually appears within about 7 days of the lone star tick bite (CDC); in practice, reported timing can range from a few days to roughly two weeks. Individual cases vary.

Diagnosis

There is no blood test that confirms STARI. A clinician makes the assessment based on the appearance and timing of the rash, a known or possible lone star tick bite, and whether you live in or visited an area where these ticks are common. Because the STARI rash closely resembles the Lyme disease rash, your clinician will also weigh which tick species and geographic region are involved. Only a licensed clinician can evaluate a rash after a tick bite.

Treatment

STARI usually resolves on its own, and people generally recover quickly. Because the rash can look like early Lyme disease and the cause is not established, some clinicians choose to treat with oral antibiotics. Whether antibiotics are necessary or beneficial for STARI has not been established, and any treatment decision is made by a licensed clinician. This page does not provide a treatment plan.

Prevention

The best protection is avoiding lone star tick bites: use an EPA-registered repellent, treat clothing and gear with permethrin, avoid tall grass and brushy areas, do a full-body tick check after being outdoors, shower soon after coming inside, and remove any attached tick promptly with fine-tipped tweezers.

Where it occurs

STARI is reported most often in the southeastern and eastern United States, matching the range of the lone star tick, which is widely distributed across the South and has expanded into the Midwest and Northeast. It tends to occur in areas where Lyme disease is uncommon, which is one clue clinicians use to distinguish the two.
When to seek care: See a licensed clinician for any rash that develops after a tick bite, or if you have fever, spreading redness, or feel unwell. Save a photo of the tick if you can, and note the date and location of the bite. Because the STARI rash can be mistaken for early Lyme disease, prompt evaluation matters - do not try to tell the two apart on your own. For emergencies such as trouble breathing or anaphylaxis, call emergency services. Educational information only — not medical advice. See our sources and disclaimer.

Southern Tick-Associated Rash Illness (STARI) — frequently asked questions

Is STARI the same as Lyme disease?+

No. STARI is linked to the lone star tick, which is not a vector of Lyme disease, while Lyme is spread mainly by blacklegged (deer) ticks. The rashes can look very similar, so a clinician should evaluate any rash that follows a tick bite.

Can a lone star tick give me Lyme disease?+

No. The lone star tick is not considered a vector of Lyme disease in the United States. A bull's-eye-type rash after a lone star tick bite may be STARI, a different condition - but only a clinician can tell them apart.

What causes STARI?+

The exact cause has not been established. An earlier theory pointed to a bacterium called Borrelia lonestari, but further research did not support it. Research is ongoing.

How soon does the STARI rash appear?+

The rash usually shows up within about a week of the bite, with reported timing ranging from a few days to roughly two weeks. Watch the bite area and see a clinician if a rash or other symptoms develop.

Is STARI dangerous?+

STARI is generally mild, and most people recover quickly - some without treatment. Serious complications have not been linked to it. Still, any rash after a tick bite should be checked by a clinician, since look-alike conditions can be more serious.

Sources used

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Southern Tick-Associated Rash Illness (STARI)

Southern tick-associated rash illness (STARI) is an expanding rash that can follow a lone star tick bite. Learn how it looks, how it differs from Lyme disease, and when to see a clinician.

Educational • not medical advice
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