What Is Erythema Multiforme?
Erythema multiforme is a skin disorder that results from an allergic reaction to either a medication or an infection. Its hallmark sign is red, patchy, raised areas that are shaped like targets (a center sore surrounded by pale red rings). These usually appear on your arms, legs, hands, or feet. They often occur within 48 to 72 hours and get better within one to three weeks.
Erythema multiforme can sometimes be confused with another skin disorder known as Stevens-Johnson syndrome, as they appear similar. However, Stevens-Johnson syndrome is more severe.
Erythema Multiforme Causes
There is no clear cause of erythema multiforme. It’s thought that about 90% of the time, it’s caused by a viral infection such as the herpes simplex virus. It can also be triggered by adenoviruses, which cause colds, as well as the flu, Epstein-Barr, or hepatitis. Other causes include:
How common is it?
Erythema multiforme is very rare. Less than 1% of all people will get it. Most cases occur in young adults in their 20s and 30s. About 20% of cases happen in kids. It’s also about five times more common in males than females.
Erythema Multiforme Symptoms
Symptoms of erythema multiforme appear suddenly, without notice. Signs include:
- Red spots, wheals, or blisters on your hands, arms, face, neck, legs, or trunk
- Joint pain
- Muscle stiffness
- Fever
- Vision changes
- Dry, bloodshot eyes
- Eye pain, itching, and/or burning
Symptoms last two to four weeks. They may go away and come back a few months later.
Erythema multiforme rash
The rash starts as itchy round, raised spots. Some may have a ring around them. They may also blister. The rash can be red, pink, purple, or even darker than your skin.
The rash often begins on your hands and feet. Over the next couple of days, it can spread to your stomach, torso, or face. It may even form painful blisters inside your mouth, on your lips, or in your eyes, butt or private parts.
Erythema Multiforme Diagnosis
Your doctor may suspect erythema multiforme when they examine you. But they may want to run some tests to know for sure. These may include:
Blood tests. Your doctor may want to check your complete blood cell count. Signs of erythema multiforme include high levels of white blood cells and mild anemia. They may also check your erythrocyte sedimentation levels. It’s a test to measure how fast your red blood cells sink to the bottom of a test tube. If it’s elevated, it could indicate erythema multiforme.
Skin biopsy. Your doctor will look at your skin closely under a microscope to look for changes that are present if you have erythema multiforme.
Chest X-ray. They’ll look for signs of a bacterial infection, such as pneumonia.
Your doctor may also check for any potential triggers of erythema multiforme. This could include checking for skin lesions that could indicate a herpes simplex virus infection or symptoms such as a cough that might mean you have pneumonia.
Erythema Multiforme Treatment
Most of the time, erythema multiforme can be treated at home. It can also resolve on its own. Your doctor may suggest:
- Antihistamines to relieve itch
- Moist compresses
- Over-the-counter or prescription cortisone creams
- Mouthwashes with numbing agents to help relieve pain (can be used up to four times a day)
If you have mouth blisters that make it difficult for you to eat, your doctor may also prescribe oral steroids to help ease pain and inflammation. If the rash is near your eyes, you may need to see an eye doctor. They can prescribe steroid eye drops.
Your doctor will also want to figure out the cause of your erythema multiforme so that it doesn't return. If your rash is due to a herpes infection, for example, you may need to take an antiviral drug like acyclovir or valacyclovir. This should help to prevent flare-ups of both herpes and erythema multiforme.
If your erythema multiforme is very severe, you may need to be hospitalized to treat complications such as dehydration or infection. Your rash will also be soaked in saline and covered with dressings until your skin heals.
Takeaways
Erythema multiforme is your skin’s reaction to a stressor such as an illness, an infection, or a medication. This skin condition looks like a bull's-eye and often presents as red, itchy, painful patches. They may be a one-time occurrence, or they may come and go. Most of the time, erythema multiforme can be treated at home with antihistamines, moist compresses, and topical steroid creams. In very rare cases, you may need to be hospitalized.
Erythema Multiforme FAQs
What is the main cause of erythema multiforme?
About 90% of the time, it’s caused by a viral, fungal, or bacterial infection, with the herpes simplex virus being the most common infection (in 70%-80% of cases). It can also be triggered by other viruses such as those causing the common cold, the flu, Epstein-Barr, or hepatitis.
What autoimmune disease is associated with erythema multiforme?
Autoimmune disease can be associated with erythema multiforme. When the two occur together, it’s known as a very rare syndrome called Rowell syndrome.
What can be mistaken for erythema multiforme?
Erythema multiforme can sometimes be confused with another, more serious skin disorder known as Stevens-Johnson syndrome.
Is erythema multiforme major contagious?
Erythema multiforme major is a more serious form of erythema multiforme where the rash has spread to places such as your eyes and mouth. Neither form of erythema multiforme is contagious.
How long does erythema multiforme take to heal?
The rash usually gets better within a couple of weeks. But it may leave dark spots that take longer to go away.
What foods should you avoid if you have erythema multiforme?
There aren’t any foods that cause erythema multiforme. But if the rash is in your mouth, it may hurt to eat or drink. Focus on liquids and soft foods. Avoid foods that are very hot, acidic, or spicy until your mouth heals.
