What Does a Lyme Disease Rash Really Look Like?
Not always a bull’s-eye rash
Often mistaken or missed
Appearance varies widely by patient
What does a Lyme disease rash look like? It’s one of the most common—and most misunderstood—questions I hear in clinical practice. :contentReference[oaicite:0]{index=0}
The erythema migrans (EM) rash is considered a hallmark sign of Lyme disease. But it does not always appear as the classic “bull’s-eye” pattern many expect.
Relying on that single image can delay diagnosis and treatment.
Lyme Disease Rashes Don’t All Look the Same
A study by Rebman and colleagues examined 271 patients with erythema migrans to better understand how Lyme disease rashes actually present.
The findings challenge common assumptions.
- Only 28% had the classic bull’s-eye rash
- Over 90% were uniformly colored
- Rashes were often round or oval—but sometimes irregular
- Many were itchy or painful
- Nearly 1 in 3 patients had multiple rashes
How Lyme Rashes Can Vary
Lyme disease rashes differ based on age, sex, timing, and location.
- Size: often expands over days, peaking around 2 weeks
- Color: red, blue-red, or less visible in darker skin tones
- Shape: round, oval, or irregular
- Location: behind knees, thighs, back—often hard to see
These variations are part of the broader spectrum described in our Lyme disease symptoms guide.
The 5 cm Rule: Helpful or Misleading?
Many guidelines suggest that an erythema migrans rash must be at least 5 cm (2 inches) to be considered diagnostic.
However, the study found this cutoff may miss cases—especially in women, who tend to have smaller rashes.
A smaller rash does not rule out Lyme disease.
Rashes May Be Missed Entirely
Not all Lyme disease patients develop a noticeable rash.
Even when present, rashes may:
- Appear in hidden areas
- Fade quickly
- Be mistaken for insect bites, eczema, or allergic reactions
This contributes to delays discussed in our delayed diagnosis guide.
Why This Matters
Early recognition of a Lyme disease rash can lead to prompt treatment and prevent more serious complications.
But recognizing it requires understanding that Lyme rashes are often subtle, variable, and easy to miss.
Start here: Lyme disease symptoms guide
Common Questions About Lyme Rashes
- What is an erythema migrans rash?
- How often do Lyme patients develop a rash?
- Can Lyme rashes be itchy or painful?
- What colors can a Lyme rash appear?
- Can you have Lyme disease without a rash?
- Are small rashes still important?
- Where are Lyme rashes most commonly found?
Have you noticed a rash that doesn’t match the classic bull’s-eye? It may still be important—especially with other symptoms.
Related Articles:
Reference:
- Rebman AW, et al. Erythema migrans characteristics. Infection. 2021.
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
I live in Canada and was infected in France while I was visiting my daughter who lives there. The rash was an expanding oval rash. Didn’t look like a bullseye so I thought I was OK. When I saw a Lyme Doctor in the USA (Canada has none) she said any rash of any kind after a tick bite is a sign of trouble. I say that needs to be made public knowledge. I would have gone to a doctor in France or at least as soon as I came home if I had known.
For sure, I got bit in Traverse City MI on a family trip 4 yrs ago, in live in AZ and lyme does not exist here and was treated by doctors that said I had cellulitis and/or shingles, rash did not go away and went to thr ER and a bullseye was spotted at the ER and Dermatologist Office, I begged them and they finally put me on doxycycline for two months, it made the rash finally disappear but 3 years later I still get swelling in my one leg and ankle and pain and brain fog. I hope you were able to at least get on some sort of medication. My brother got bit by a tick in Michigan, he did not get lyme but another tick issue and after several doctors, he got one to put him on minocycline for two years. sorry about spelling. I wish you luck and that you are ok.
I have what looks like Erthema Migrans Rash. They keep telling me I test negative for Lyme. My speech is now effected and I was diagnosed last Sept with a tick borne illness that made me very sick. soon after that I developed red spots on both wrist with hard centers. Soon after that this happened on my left breast, left side of my belly and all around my groin. I am at wits end to figure out if this is due to Lyme, most doctors I’ve been to dismiss it when I bring it up. I live in Vt. and would like to see a Lyme specialist but insurance won’t cover it unless diagnosed. Anyone know the next step. They want to send me to a dermatologist and sleep study. I already have seen a neurologist and did not have stroke. I’m 61 and feeling crappy all the time. No energy ,wake up feeling tired. I seem to loose balance and sometimes trip easily. Hot Flashes, slurred speech and my brain does not work well in the afternoon.
You also need to write about the different rash you get in Europe (expanding oval rash from Borrelia garinii).
There are Canadians who have family in the UK, France and Germany and visit them once a year for a month.