What is erythema multiforme?

Erythema multiforme is a skin disorder. It may be caused by the body overreacting to an infection or medicine. It causes red, raised skin patches on the body. These patches often look like "targets." They may have dark circles with purple-gray centers. 

You can get this skin problem over and over again. It often lasts for 2 to 4 weeks each time.

What causes erythema multiforme?

Most often, this skin problem is caused by the herpes simplex virus. Other causes are:

• Fungal and bacterial infections, such as Mycoplasma pneumoniae

• An interaction with certain medicines, such as antibiotics or nonsteroidal anti-inflammatory medicines

• Other infectious diseases

Certain vaccines, such as for hepatitis B

Who is at risk for erythema multiforme?

Anyone can get erythema multiforme. But these factors may raise your risk: 

• Being male

• Being in your 20s to 40s, but it can occur at any age

What are the symptoms of erythema multiforme?

These are the most common symptoms of erythema multiforme:

• Sudden, red patches and blisters, often on the palms of hands, soles of feet, and face

• Round red "targets" (dark circles with purple-gray centers)

• Itching

• Cold sore

• Fatigue

• Joint pain

• Fever

These symptoms may look like other skin problems. Always talk with your healthcare provider for a diagnosis.

How is erythema multiforme diagnosed?

Your healthcare provider will ask about your health history and do a physical exam. They can often diagnose this skin condition by simply looking at your skin. You may also need one or more of these tests:

• Blood test. A blood sample can help find or rule out possible causes, such as an infection.

• Biopsy. Your healthcare provider may remove a piece of skin and have it checked under a microscope.

How is erythema multiforme treated? 

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

You may not need treatment if you have a mild case of erythema multiforme. It may go away on its own. If you need treatment, it may involve:

• Treatment of the disease causing the skin problem

• Stopping a medicine if it’s causing the reaction

• Medicines for pain, swelling, or itching

• Cool compresses

• Steroids

• Antibiotics

• Antiviral medicine taken by mouth if herpes simplex virus is the cause

What are possible complications of erythema multiforme?

If you develop a severe form of erythema multiforme (erythema multiforme major), it can become fatal. It is often caused by a reaction to medicine rather than an infection. Erythema multiforme major is also known as Stevens-Johnson syndrome. This condition involves blistering and peeling of much larger areas of skin. It often involves mucous membranes, such as the mouth or eyes. You may need to go to the hospital right away and be given IV fluids and other treatment.

When should I call my healthcare provider?

If you have severe symptoms of erythema multiforme, go to your emergency room or call 911. If a large area of skin or mucus membranes are involved, it is an emergency.

Key points about erythema multiforme

• Erythema multiforme is a skin disorder. It’s a hypersensitivity reaction to an infection or medicine.

• Red, raised skin patches appear on the body. These patches often look like “targets.”

• The most common cause is the herpes simplex virus.

• A physical exam can often diagnose it. Other tests, such as a biopsy, may help find out what is causing it.

• Treating the underlying cause, such as an infection, can ease symptoms.

• A severe form of this skin problem can be deadly.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your provider if you have questions.