What Does a Lyme Disease Rash Look Like?

Lyme disease rashes vary in appearance.
Many are not the classic bull’s-eye rash.
Recognizing erythema migrans early may help speed diagnosis and treatment.

What does a Lyme disease rash look like? A Lyme disease rash, called erythema migrans, can vary considerably in size, shape, color, and location. Although many people expect the classic bull’s-eye rash, the most common early Lyme disease rash—called erythema migrans (EM)—can vary considerably in size, shape, color, and location. It may appear as a solid red patch, an oval lesion, a blue-red discoloration, or the familiar ring-shaped rash. Recognizing these variations may help lead to earlier diagnosis and treatment.

A photograph alone cannot confirm or exclude Lyme disease. A clinician should interpret the appearance of a rash together with symptoms, possible tick exposure, and the likelihood of Lyme disease in your area. For additional educational examples, the Centers for Disease Control and Prevention (CDC) Lyme disease rash gallery illustrates both erythema migrans and several skin conditions that can resemble Lyme disease.

The study by Rebman and colleagues, entitled “The presenting characteristics of erythema migrans vary by age, sex, duration, and body location”, examined why Lyme disease rashes often appear differently from one patient to another.²

Erythema migrans remains the hallmark skin manifestation of early Lyme disease. However, contrary to popular belief, many patients never develop the classic target lesion. Instead, the rash may be uniformly red, oval, irregular, bluish-red, or lack central clearing entirely.

Learn more about the early symptoms of Lyme disease and why the rash is only one component of making a clinical diagnosis.

The many appearances of erythema migrans

One of the most important messages from the Rebman study is that most Lyme disease rashes are not the classic bull’s-eye rash. Erythema migrans can appear as a solid red plaque, an oval lesion, a blue-red discoloration, or a rash with central clearing. The appearance varies depending on the patient, the location of the rash, and how long it has been present.

These findings are supported by an earlier study by Aucott and colleagues. In an internet survey involving more than 3,100 participants, nearly three-quarters correctly recognized the classic bull’s-eye lesion, but only about one in five correctly identified the nonclassic forms of erythema migrans. Nearly one-quarter mistakenly identified a simple tick bite reaction as Lyme disease, highlighting the need for better public education regarding Lyme disease rash recognition.¹

Diverse characteristics of Lyme disease rash

Rebman and colleagues evaluated 271 patients with erythema migrans to better understand how Lyme disease rashes vary among individuals.²

“We studied associations between these presenting characteristics, as well as whether they were associated with age, sex, EM duration, body location, and initiation of antibiotics,” the investigators wrote.

The patients were enrolled from three study sites in Maryland and southeastern Pennsylvania. Individuals with rashes smaller than 5 cm or illnesses lasting longer than three months were excluded.

The study found:

• EM size increased during approximately the first two weeks after onset.
• Males had larger rashes than females.
• Males were more likely to develop blue-red lesions.
• Older adults were less likely to develop classic central clearing.
• Many lesions occurred behind the knees or thighs where ticks often remain unnoticed.
• Nearly one-third of patients had multiple erythema migrans lesions.
• Approximately one-third experienced pain at the site of the rash.
• More than half reported itching.
• Only 28% demonstrated the classic bull’s-eye appearance.
• Most lesions were homogeneous rather than ring-shaped.
• Nearly 9% developed vesicles.

Can a Lyme disease rash itch?

Yes. Many people assume that erythema migrans is never itchy, but this is not always true. In the Rebman study, just over half of patients reported itching, while approximately one-third reported pain at the site of the rash.

Because itching is common with insect bites, allergic reactions, fungal infections, and other skin disorders, it should never be used alone to determine whether a rash is Lyme disease. Instead, clinicians evaluate the overall appearance of the lesion, whether it is expanding, accompanying symptoms, tick exposure, and geographic risk.

Normal tick bite vs. Lyme disease rash

A simple tick bite commonly produces a small localized area of redness that develops within the first day or two after the bite and gradually fades. In contrast, erythema migrans usually expands over several days, often reaching several inches in diameter. However, because there can be overlap, distinguishing a normal tick bite from early Lyme disease is not always straightforward.

The CDC describes erythema migrans as a rash that typically expands over several days. However, in clinical practice I have evaluated patients with Lyme disease whose rashes showed little obvious expansion by the time they were examined. For this reason, assessment should consider the overall clinical picture—including symptoms, possible tick exposure, and the appearance of the rash—rather than relying solely on whether expansion is observed at the office visit.

The Aucott study demonstrated that people frequently confuse uncomplicated tick bite reactions with erythema migrans, while simultaneously failing to recognize many nonclassic Lyme disease rashes. This explains why diagnosis should never rely on appearance alone.

If uncertainty remains, physicians should consider the patient’s symptoms together with the limitations of early Lyme disease testing, since antibody tests may remain negative during the first few weeks after infection.

Additional information on skin conditions that may resemble Lyme disease is available in the Lyme disease misdiagnosis section.

Symptoms may appear before the rash

Although erythema migrans is considered the hallmark sign of early Lyme disease, patients do not always notice the rash first. In a 2023 follow-up study, Rebman and colleagues found that approximately 38% of patients first experienced viral-like symptoms—such as fatigue, fever, muscle aches, or headache—before recognizing erythema migrans.³

Patients whose illness began with nonspecific symptoms experienced longer delays before receiving antibiotic treatment and were more likely to present with multiple erythema migrans lesions, suggesting that early recognition of Lyme disease remains challenging even when a rash eventually develops.

These findings reinforce the importance of considering Lyme disease even before a characteristic rash becomes apparent, particularly in patients with compatible symptoms and possible tick exposure.

Atypical Lyme disease rashes

Not every case of erythema migrans resembles the textbook bull’s-eye rash. In 2024, Khanna and Goebel described a 69-year-old woman whose Lyme disease presented with a homogeneous purplish expanding rash without central clearing or a target appearance.⁴

The patient recalled a recent tick bite and developed an enlarging itchy lesion. Although her initial laboratory testing was not fully confirmatory, clinicians recognized the rash as compatible with early Lyme disease and treated her with doxycycline. Her symptoms and skin lesion improved with therapy.

This case illustrates an important clinical point: Lyme disease should not be excluded simply because a rash lacks the classic bull’s-eye appearance. Physicians must consider the overall clinical picture, including exposure history, symptoms, and the evolution of the skin lesion.

Concerns with limiting the size of a Lyme disease rash

The Rebman study also raised concerns about relying too strictly on a 5 cm (2-inch) cutoff when evaluating erythema migrans. The authors noted that applying a rigid size threshold in research or surveillance settings may exclude patients with otherwise suggestive clinical histories and epidemiologic risk.

This concern may be particularly relevant for women, who had smaller rashes on average in the study. A small but expanding rash after a tick bite should not be dismissed solely because it has not yet reached 5 cm in diameter.

The investigators also emphasized that nearly 96% of participants in their cohort self-identified as non-Hispanic White, limiting conclusions about the appearance of erythema migrans in people with darker skin tones. Additional studies involving more diverse populations are needed.

Authors’ conclusion

“Given that EM remains a clinical diagnosis, it is essential that both physicians and the general public are aware of its varied manifestations.”

Editor’s note

Unfortunately, fewer than half of patients with Lyme disease recognize or recall an erythema migrans rash. This study highlights the remarkable diversity of rashes among those who do develop one.

The key clinical message is that Lyme disease should not be judged by a single rash pattern. A bull’s-eye lesion is highly suggestive, but many patients develop solid red, oval, blue-red, itchy, painful, vesicular, or multiple erythema migrans lesions. Others may never notice a rash at all.

When evaluating a patient with a possible tick bite, clinicians should consider the appearance and evolution of the rash together with symptoms, geographic exposure, and the limitations of early Lyme disease testing. A careful clinical assessment remains the cornerstone of early diagnosis.

Frequently Asked Questions

What does a Lyme disease rash look like?

A Lyme disease rash, called erythema migrans, can appear in many forms. Although the classic bull’s-eye rash is well known, many patients develop a solid

red patch, an oval lesion, a bluish-red rash, or the classic bull’s-eye. The rash usually expands gradually over several days and may continue to enlarge if left untreated.

Does every Lyme disease rash look like a bull’s-eye?

No. In the Rebman study, only about 28% of erythema migrans lesions had the classic bull’s-eye appearance. Most were uniformly red, oval, irregular, or had central lightening or darkening rather than a distinct target pattern.

Can a Lyme disease rash itch?

Yes. More than half of patients in the Rebman study reported itching, while about one-third experienced pain at the site of the rash. Although many Lyme disease rashes are not itchy, itching does not rule out erythema migrans.

Can a Lyme disease rash be smaller than 2 inches?

Yes. Early erythema migrans may initially measure less than 5 cm (2 inches) before expanding. A small but enlarging rash following a tick bite should be evaluated clinically rather than dismissed based solely on its size.

Can you have Lyme disease without a rash?

Yes. Many people with Lyme disease never notice an erythema migrans rash. Others develop flu-like symptoms before recognizing a rash. The absence of a rash does not exclude Lyme disease.

Is every bull’s-eye rash Lyme disease?

No. Ringworm, insect bite hypersensitivity reactions, fixed drug eruptions, granuloma annulare, pityriasis rosea, Southern tick-associated rash illness (STARI), and several other skin conditions may resemble erythema migrans. Likewise, many Lyme disease rashes are not bull’s-eye lesions.

Clinical Takeaway

Erythema migrans remains the hallmark skin manifestation of early Lyme disease, but it is much more variable than many people realize. The rash may be red, blue-red, oval, irregular, itchy, painful, multiple, or lack the classic bull’s-eye appearance altogether.

Studies by Aucott and Rebman demonstrate that both patients and healthcare professionals frequently misidentify Lyme disease rashes, leading to delayed diagnosis or unnecessary concern about benign skin conditions. More recent reports continue to emphasize that atypical erythema migrans is common and requires careful clinical recognition.

Recognizing the diverse appearances of erythema migrans—and understanding that many patients never develop a classic bull’s-eye rash—may lead to earlier diagnosis and more timely treatment of Lyme disease.

Related Articles

Learn more about the diagnosis and early manifestations of Lyme disease:

How Accurate Are Lyme Disease Tests?
Why Early Lyme Disease Tests Can Be Negative
Common Lyme Disease Misdiagnoses
Neurologic Lyme Disease
Persistent Lyme Disease: An Overview

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