Erythema migrans and erythema multiforme both cause target- or bull’s-eye-shaped lesions. Erythema migrans is due to Lyme disease. Erythema multiforme is an immune-mediated hypersensitivity skin condition.
If you have target lesions, your doctor may order tests to determine the underlying cause. They can then advise on suitable treatments.
Treatments for erythema migrans and erythema multiforme are different, so it’s important to distinguish between the two conditions.
Read on to learn more about erythema migrans and erythema multiforme, including the causes, other symptoms, treatment options, and more.
Have a look at the table below for an overview of the similarities and differences between erythema migrans and erythema multiforme.
| Erythema migrans | Erythema multiforme | |
|---|---|---|
| Lesions | • target or bull’s-eye rash • red, pink, purple, or bruise-like • flat or slightly raised • usually not itchy • expands from the site of the tick bite | • target or bull’s-eye rash • red, pink, purple, or darker than surrounding skin • usually slightly raised • itchy or burning • usually develops on the hands, feet, stomach, chest, face, or back |
| Causes | • a bacterial infection from a deer tick bite • usually due to the Borrelia burgdorferi bacterium | • certain infections, such as herpes simplex virus (HSV) type 2, influenza virus, SARS-CoV-2, and Epstein-Barr virus • some medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), antibiotics, and antiepileptics |
| Other symptoms | • headache • fever • chills • fatigue • muscle and joint aches • swollen lymph nodes | • high temperature • headache • aches and pains • a general feeling of being unwell |
| Diagnosis | • blood tests to check for antibodies | • usually based on the appearance of the rash • blood tests and other tests to rule out other conditions |
| Treatments | • antibiotics | • antihistamines • steroids • antiseptic mouthwash • a stay at the hospital, in severe cases |
Both erythema migrans and erythema multiforme can cause a rash or lesion that has a bull’s-eye or target shape. This means that there’s a solid circular rash surrounded by a ring.
Erythema migrans
The color of an erythema migrans rash may be:
- red
- pink
- purple
- bruise-like
The center of the rash may be darker or lighter than the outer part. The lesion may be flat or slightly raised.
An erythema migrans rash doesn’t usually itch or feel hot to the touch.
Erythema multiforme
The color of an erythema multiforme rash may be:
- red
- pink
- purple
- darker than the surrounding skin
Erythema multiforme can cause an itchy or burning sensation. The lesion is usually slightly raised.
An erythema migrans rash typically appears in the area of a tick bite as an early symptom of Lyme disease. The bite mark will be in the center of the rash as the rash expands.
On the other hand, erythema multiforme rashes typically appear on the:
- hands
- feet
- stomach
- chest
- face
- back
In some cases, they can also develop:
- in the mouth
- on the lips
- on the eyes
- on the anus
- on the genitals
Although erythema migrans and erythema multiforme present in similar ways, the conditions have different causes.
Erythema migrans
Erythema migrans is a symptom of Lyme disease. Lyme disease is a bacterial infection that can develop if a black-legged tick, or deer tick, bites you. It’s typically due to the Borrelia burgdorferi bacterium.
Ticks can bite any part of the body, but they usually bite areas like the:
- scalp
- armpits
- groin
In most cases, the tick bacterium will only spread to you if the tick is attached to your body for more than 24 hours.
Erythema multiforme
In 90% of cases, erythema multiforme develops due to an infection. Infections that can cause erythema multiforme include:
- influenza virus
- HSV-2
- SARS-CoV-2
- Epstein-Barr virus
- cytomegalovirus
- vulvovaginal candidiasis
- orf virus
Certain medications can also cause erythema multiforme. These include:
- NSAIDs
- antibiotics
- antiepileptics
- some vaccinations
Erythema migrans and erythema multiforme can both occur alongside other signs and symptoms. These can help distinguish between the two conditions.
Erythema migrans
Other symptoms of Lyme disease can include flu-like symptoms, such as:
If the infection spreads, you may experience symptoms like:
- rashes on other parts of your body
- dizziness
- shortness of breath
- neck stiffness
- heart palpitations
- facial palsy, or weakness of the facial muscles
- nerve pain
- shooting pains, tingling, or numbness in the hands or feet
Erythema multiforme
Other symptoms of erythema multiforme can include:
- headache
- high temperature
- aches and pains
- a general feeling of being unwell
If you have a bull’s-eye rash, your doctor will likely begin by performing a physical examination and taking a full medical history. They’ll also ask questions about any other symptoms you have.
If your doctor suspects erythema migrans, they’ll likely order a blood test to check for antibodies. As it can take a number of weeks after the tick bite for the antibodies to develop, you may need more than one test.
On the other hand, if your doctor thinks you may have erythema multiforme, they may be able to confirm the diagnosis based on your medical history and the appearance of the rash. But they may order tests to rule out other causes. Possible tests include:
- blood tests
- liver function tests
- skin biopsy
- chest X-ray
Treatments for erythema migrans and erythema multiforme are different.
Erythema migrans
The main treatment for Lyme disease, the cause of erythema migrans, is antibiotics.
It’s important to receive treatment as early as possible for Lyme disease. Contact a doctor as soon as you have concerns about Lyme disease or tick bites.
Erythema multiforme
In mild cases, you may not require specific treatments for erythema multiforme. But if symptoms affect your eyes, you’ll need to contact a doctor, as potentially serious complications can develop.
Remedies that may help manage symptoms in mild cases include:
- oral antihistamines or topical steroids to alleviate itchiness
- antiseptic mouthwashes, if symptoms affect the mouth
- treatments for any infections
If a medication has caused your erythema multiforme, your doctor may recommend stopping the medication. However, it’s important to keep taking any medication your doctor has prescribed until they advise otherwise.
In severe cases of erythema multiforme, a stay in the hospital may be necessary.
Aside from erythema migrans and erythema multiforme, other conditions can cause a rash that resembles a bull’s-eye or target-like shape. These include:
- urticaria, or hives
- toxic epidermal necrolysis, a form of Stevens-Johnson syndrome
- fixed drug eruption, where the rash appears in the same place when taking a certain medication
- polymorphic light eruption, which is a reaction to sunlight exposure
- erythema annulare centrifugum
- subacute cutaneous lupus erythematosus, a type of lupus that affects the skin
- Rowell syndrome, a rare type of lupus
- polymorphic eruption of pregnancy, which can develop in the last 3 months of pregnancy
- bullous pemphigoid
- paraneoplastic pemphigus
- linear IgA bullous disease, an autoimmune blistering condition
Erythema migrans and erythema multiforme both cause lesions that have a target or bull’s-eye shape. But they have different causes and need different treatments.
Erythema migrans is a symptom of Lyme disease. Lyme disease is a bacterial infection that can happen due to a deer tick bite. If you have Lyme disease, you’ll need antibiotics.
Erythema multiforme is a skin condition that can develop in response to some infections and medications. Medical treatments may not be necessary in mild cases, unless symptoms affect your eyes. Remedies to alleviate pain and itchiness can help.
If you have a bull’s-eye or target rash, your doctor will perform a physical examination and ask you questions about your symptoms. They may also order blood tests and other tests to confirm the diagnosis or rule out other possible causes.
Because some causes, such as Lyme disease, require prompt treatment, it’s important to seek medical advice as soon as you notice the rash or have any concerns about tick bites.