STARI vs Lyme Disease: How to Tell the Difference After a Tick Bite
STARI vs Lyme disease can be difficult to tell apart after a tick bite. Both can cause a similar rash and flu-like symptoms—but they are not the same condition.
This confusion can delay diagnosis and treatment.
In some cases, patients are told they have a mild illness when a more serious tick-borne infection is possible. Understanding the differences between STARI and Lyme disease is important—especially when symptoms persist or evolve.
In clinical practice, I have seen patients in the southern United States diagnosed with STARI who were not informed that Lyme disease could still be a possibility.
As tick populations expand and overlap geographically, relying on location alone can lead to missed or delayed diagnosis. A Lyme-like rash in the South does not always exclude Lyme disease.
STARI and Lyme disease share many similarities. In their article
“Southern Tick-Associated Rash Illness: Florida’s Lyme Disease”
, Abdelmaseih and colleagues describe a patient case highlighting these similarities and differences.1
Case Presentation
The patient was bitten by a lone-star tick on her right leg while camping in Gainesville, Florida. After removing the tick she noticed a pruritic target-like erythematous lesion.
Two weeks later she developed persistent fever, headache, and diffuse myalgias for four days following the tick bite.
On presentation she had a fever of 100.5°F and tachycardia of 127 BPM. Laboratory testing revealed a low white blood cell count, anemia, thrombocytopenia, and elevated liver function tests.
Fortunately, the patient’s symptoms resolved with a 14-day course of doxycycline.
STARI and Lyme Disease: Similarities and Differences
The authors discussed several similarities between STARI and Lyme disease.
- “The associated rash is similar if not indistinguishable from Lyme disease erythema migrans, with lymphocytic dermal infiltrate.”
- Both STARI and Lyme disease diagnoses are based largely on clinical evidence.
- “At the present time there is no approved diagnostic modality to identify STARI; therefore diagnosis must rely on clinical evidence including erythema migrans and tick exposure.”
Geographic Clues in Diagnosis
The diagnosis of STARI and Lyme disease often relies on geographic exposure.
“Diagnosis usually relies on geographic association (STARI from central Texas and Oklahoma eastward across the southern states and along the Atlantic coast as far north as Maine, versus Lyme disease in the Northeast, Mid-Atlantic, and Upper Midwest).”
Geographic patterns are becoming less reliable as tick populations expand.
However, the authors did not address reports documenting the presence of lone-star ticks in the Northeast, Mid-Atlantic, and Upper Midwest, or the presence of deer ticks in parts of the South.
Long-Term Consequences Remain Uncertain
It has been widely assumed that STARI does not cause long-term complications. However, much about the illness remains unknown.
“A recent study has suggested that STARI is transmitted by the lone-star tick Amblyomma americanum; however, much is still unknown about STARI.”
Treatment Considerations
The treatment of STARI is also uncertain.
“STARI is often treated as Lyme disease with doxycycline twice daily for 14 days; however, there is no approved treatment yet.”
The authors concluded that STARI is an emerging Lyme-like illness producing erythema migrans rash, although its true incidence remains unknown because it is not nationally reportable.
Questions Addressed in This Podcast
- What is STARI?
- Are there differences between STARI and Lyme disease rashes?
- Are there differences in the ticks responsible for infection?
- How is STARI diagnosed compared with Lyme disease?
- What clinical evidence is needed to diagnose STARI?
- What are the consequences if Lyme disease or co-infections are overlooked?
- What do we know about ticks in the southern United States?
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Frequently Asked Questions
What is STARI?
STARI (Southern Tick-Associated Rash Illness) is a Lyme-like illness transmitted by the lone-star tick that produces an erythema migrans rash similar to Lyme disease.
How is STARI different from Lyme disease?
STARI and Lyme disease share similar rashes and symptoms, but they are transmitted by different ticks. STARI is associated with lone-star ticks, while Lyme disease is transmitted by black-legged (deer) ticks.
How is STARI diagnosed?
There is no approved diagnostic test for STARI. Diagnosis is based on clinical findings, including rash appearance and tick exposure in endemic regions.
How is STARI treated?
STARI is commonly treated with doxycycline for 14 days, similar to Lyme disease, although standardized treatment guidelines have not been established.
Related Articles:
Lyme Disease Co-infections
Borrelia miyamotoi
Powassan Virus
Babesia
References:
- Abdelmaseih R, Ashraf B, Abdelmasih R, Dunn S, Nasser H. Southern Tick-Associated Rash Illness: Florida’s Lyme Disease Variant. Cureus. 2021;13(5):e15306.
About the Author
Dr. Daniel Cameron is a board-certified physician and past president of the International Lyme and Associated Diseases Society (ILADS).
Through his Inside Lyme Podcast and clinical commentary, he reviews research and case reports to help clinicians and patients better understand Lyme disease, co-infections, and Lyme-like illnesses such as STARI.
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
Emerging? I had multiple tick bites as a child during summer trips to Kentucky, in the early to mid 1970s.
I has taken a while for doctors and researchers to document ticks and tick borne diseases in new areas. Until someone writes it up, the typical answer might be we don’t have tick or we don’t have tick borne diseases in this area.
I have been ill since the spring of 1987 . I lived in a wooded area near a lake . I saw several Possums and Raccoons when I lived there . I had not lived there long and I was clearing brush and taking it into the woods . When I finished and was cleaning up . I found a Tick embedded in my left arm . I removed it with tweezers and flushed it .It wasn’t long before subtle changes began .Visual problems ,fatique and and a strange sensation in my left foot and left arm . Several months later I was diagnosed with Hemianopsia . I started having memory problems .Nobody seemed to know what was wrong . It wasn’t until 1999 and my mother was watching a show about Lyme Disease and she called me to tell me how the rash shown on the show looked the same as the one I developed after the Tick bite .I contacted a Infectious disease Doctor and he did treat me with iv antibiotics . I did get better after being bed ridden and having to use a walker while undergoing