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Rash guideLyme disease rash: what it looks like, and what it doesn’t
The Lyme rash, called erythema migrans, is the clearest early sign of Lyme disease, but it often isn’t a bullseye. Here is how to recognize it, how it can look on different skin, and the rashes it gets confused with.
The short version
CDC describes the erythema migrans (EM) rash like this:
- It appears in over 70 percent of people with Lyme disease.
- It starts where the tick bit, 3 to 30 days later (about 7 days on average).
- It slowly expands over several days, up to 12 inches (30 cm) or more.
- It often feels warm, but is rarely itchy or painful.
- It may or may not clear in the middle.
Four ways a Lyme rash can look
These are simple illustrations, not photos, so you can see the patterns side by side. For real clinical photos, see CDC’s gallery of Lyme disease rashes.
CDC’s own photo gallery includes rashes with a crust in the center, a small bump in the middle, a bluish tint with no clearing, and red-blue patches behind the knee. The variety is the point. A rash doesn’t have to be a bullseye to be Lyme.
The Lyme rash on darker skin
Most medical photos of the Lyme rash show light skin. On brown and black skin, the rash can look purple, dark brown or bruise-like, and the redness that textbooks describe can be hard to see. Watch for a patch that keeps getting bigger over several days, and for warmth or a change in texture. If you’re unsure, take a photo each day with a coin or ruler beside it so a doctor can see it grow.
Lyme rash or something else?
Several common rashes form rings or circles. CDC lists these look-alikes:
| Rash | How it often differs from a Lyme rash |
|---|---|
| Ringworm (a fungal skin infection) | A ring-shaped rash that is usually red, itchy and has raised, often scaly edges. A Lyme rash is rarely itchy. |
| Insect bite reaction | A large, itchy allergic reaction to a bite. Reactions to the tick bite itself tend to appear soon after the bite, while a Lyme rash usually takes days to appear. |
| Pityriasis rosea | Round or oval pink, scaly patches with a raised border that can itch, often several at once. |
| Granuloma annulare | Small reddish bumps arranged in a ring. |
| Hives | Raised welts, often triggered by food, infection or medicine, that may burn or itch and move around. |
| Fixed drug reaction | A dark circle that appears up to two weeks after taking a medicine and comes back in the same spot each time. |
There is also a rash from the lone star tick, common in the South and East, that can look very similar to a Lyme rash. It’s called STARI (southern tick-associated rash illness). The lone star tick does not spread Lyme, so tell your doctor which tick bit you if you know.
A typical EM rash in someone who may have been bitten is often enough for a doctor to diagnose Lyme. Blood tests can be negative in the first weeks, so a negative early test doesn’t rule it out.
How to track a rash
- Take a clear photo in daylight, with a coin or ruler for scale.
- Draw around the edge with a pen if you can.
- Photograph it again each day at the same time.
- Note any fever, chills, aches or tiredness.
- See a healthcare provider if it keeps spreading or you feel unwell.
We are collecting real experiences about what their rash looked like from people who have lived it, shared with their permission. As stories come in, they will appear here, clearly marked as personal experience rather than medical advice.
Frequently asked questions
Is the Lyme rash always a bullseye?
No. Many Lyme rashes are an evenly red or bluish patch with no rings. CDC says the rash may or may not clear in the center.
Does the Lyme rash itch?
Rarely. It often feels warm to the touch, but CDC says it is rarely itchy or painful. A very itchy ring is more likely something else, such as ringworm.
How big does a Lyme rash get?
It slowly expands over several days and can reach 12 inches (30 cm) or more across.
Can the rash go away on its own?
Yes, the rash can fade without treatment, but the infection can still spread. A fading rash is not a reason to skip seeing a doctor.
Where on the body does the Lyme rash appear?
Anywhere a tick bit, often in warm, hidden places like the armpit, groin, behind the knee, the waistline or the scalp.