Erythema multiforme is a skin condition that causes distinctive target-shaped lesions to appear suddenly on the skin. It can range from a mild rash to a serious, life-threatening reaction. In Canada, most people who develop this condition have the mild form, which clears up on its own within a few weeks. However, knowing the signs, causes, and when to seek care is important for your health and peace of mind.
What Is Erythema Multiforme?
Erythema multiforme is a skin reaction, not a contagious disease. It typically causes round, target-like spots that appear on both sides of the body equally. These lesions often show up on the arms, legs, and inside the mouth.
There are two main forms of this condition. The first is the minor form, which is common and generally not dangerous. The second is the major form, which is more serious and much rarer.
Erythema Multiforme Minor
The minor form causes target-shaped spots mainly on the limbs. These spots usually go away on their own within one to six weeks. Most people do not need medical treatment for this form.
Erythema Multiforme Major (Stevens-Johnson Syndrome)
The major form is a more severe reaction. It can cause painful blisters on the body, eyes, mouth, and genital area. This form is also known as Stevens-Johnson syndrome and can be life-threatening. It requires immediate medical attention. You can read more about serious skin reactions at the Mayo Clinic’s Stevens-Johnson syndrome resource.
Common Causes of Erythema Multiforme
Erythema multiforme is caused by the body’s immune reaction to an infection or a medication. In many cases, however, doctors cannot find a clear cause. Understanding possible triggers can help you and your doctor manage the condition.
Infections That Can Trigger It
The most common infection linked to erythema multiforme minor is the herpes simplex virus (HSV). This is the same virus that causes cold sores. Other infections that may trigger the condition include:
Mycoplasma pneumoniae (a type of bacterial lung infection)
Other viral or bacterial infections
Medications That May Cause a Reaction
Certain medications can also trigger erythema multiforme. These include:
Sulfonamide antibiotics
Tetracyclines
Amoxicillin and ampicillin
Anti-inflammatory drugs (such as ibuprofen)
Anticonvulsant medications (used to treat seizures)
If you have recently started a new medication and notice a skin rash, speak with your pharmacist or family doctor right away. Do not stop taking a prescribed medication without medical guidance.
Other Known Triggers
In some cases, other factors may play a role. These include a history of radiation therapy and, in rare cases, cocaine use. Exposure to any known trigger increases your risk of developing erythema multiforme. For more information on skin reactions and their causes, visit Healthline’s guide to erythema multiforme.
Symptoms of Erythema Multiforme
Symptoms of erythema multiforme can range from mild to severe. Because many of these symptoms can look like other skin conditions, it is important not to self-diagnose. Always check with a healthcare provider for an accurate diagnosis.
Skin Symptoms
The most recognizable sign is the target-shaped lesion. These spots have a red centre surrounded by rings of colour, making them look like a bullseye. Key skin symptoms include:
Round, target-like spots or patches on the skin
Lesions that appear mainly on the arms and legs
Blisters or raised areas in the centre of the lesion
Rash that appears equally on both sides of the body
Itching or burning around the affected areas
Rash that fades within one to six weeks
Other Symptoms to Watch For
Beyond the skin, erythema multiforme can cause a range of other symptoms. These may include:
Fever
General feeling of being unwell
Joint pain or aching
Sores inside the mouth
Red, dry, or burning eyes
Changes in vision
Eye symptoms and mouth sores should never be ignored. These signs can point to the more serious major form of erythema multiforme. Seek care promptly if they appear.
How Is Erythema Multiforme Diagnosed?
Your doctor will begin by asking about your symptoms and your medical history. In most cases, a diagnosis of erythema multiforme can be made simply by examining the skin. The target-shaped lesions are quite distinctive and often make the diagnosis straightforward.
However, if the lesions do not look typical, your doctor may refer you to a dermatologist. A skin biopsy may be needed in some cases. This involves taking a small sample of skin tissue and examining it under a microscope. Results help confirm the diagnosis and rule out other conditions.
In Canada, your family doctor is a good first point of contact. If you do not have a family doctor, a walk-in clinic can help with assessment and referral if needed.
Treatment Options for Erythema Multiforme
The good news is that erythema multiforme minor often clears up on its own without any treatment. The rash usually fades within one to six weeks. Most people recover fully without complications.
Treating the Underlying Cause
If a specific trigger is found, treating it can help the skin heal faster. For example:
Herpes simplex virus: Oral antiviral medication such as acyclovir may be prescribed.
Mycoplasma infection: Antibiotics may be recommended by your doctor.
Medication triggers: The offending drug will typically be stopped under medical supervision.
Managing Symptoms
Even without a clear cause, your doctor can help manage uncomfortable symptoms. Common approaches include:
Itching: Oral antihistamines or topical corticosteroids can provide relief.
Mouth pain: A mouthwash containing a local anaesthetic or antiseptic can reduce pain and prevent secondary infection.
Eye problems: An eye specialist (ophthalmologist) should be consulted if you have eye symptoms.
For the major form of erythema multiforme, hospital care is usually required. Treatment is more intensive and may involve intravenous fluids, wound care, and close monitoring. Learn more about skin condition management through Health Canada’s official health resources.
Preventing Erythema Multiforme From Coming Back
If you have had erythema multiforme, finding the trigger is the most important step in prevention. Avoiding that trigger can greatly reduce your chances of a recurrence.
For example, if a specific antibiotic caused your reaction, make sure to tell every healthcare provider you see going forward. This includes your family doctor, pharmacist, walk-in clinic staff, and any specialists. It is a good idea to keep a note of it in your health records or carry a medical alert card.
If the herpes simplex virus is your trigger, your doctor may suggest long-term antiviral therapy to prevent future outbreaks and related skin reactions. Talk to your family doctor about the best prevention plan for your situation.
When to See a Doctor
You should see a doctor any time you develop an unexplained skin rash, especially one that looks like target-shaped spots. If you also have a fever, mouth sores, or eye symptoms, do not wait. Seek care right away.
For mild symptoms with no eye or mouth involvement, your family doctor or walk-in clinic is a great first step. Most provincial health plans in Canada cover visits for skin concerns like this. Your doctor can assess the rash, identify any triggers, and recommend appropriate care.
If your symptoms are severe, spreading rapidly, or you are having difficulty eating or seeing, go to your nearest emergency department. The major form of erythema multiforme is a medical emergency and should not be managed at home.
Always speak with a qualified healthcare provider before starting, stopping, or changing any treatment. The information in this article is for educational purposes only and does not replace professional medical advice.
Frequently Asked Questions About Erythema Multiforme
What does erythema multiforme look like?
Erythema multiforme causes distinctive target-shaped or bullseye lesions on the skin. These round spots have a red centre surrounded by rings of lighter and darker colour. They typically appear on the arms, legs, and sometimes inside the mouth.
Is erythema multiforme contagious?
No, erythema multiforme itself is not contagious. It is an immune reaction, not an infection that spreads from person to person. However, the underlying trigger, such as the herpes simplex virus, can be contagious.
How long does erythema multiforme last?
In most cases, erythema multiforme minor clears up on its own within one to six weeks. Some people may experience recurring episodes, especially if the trigger is not identified and avoided. Your doctor can help create a plan to reduce the risk of it coming back.
What is the difference between erythema multiforme and Stevens-Johnson syndrome?
Stevens-Johnson syndrome is the severe, major form of erythema multiforme. It causes painful blisters that affect the skin, mouth, eyes, and genitals, and can be life-threatening. The minor form, by contrast, is much milder and usually resolves without serious complications.
Can medications cause erythema multiforme?
Yes, certain medications are known triggers for erythema multiforme. These include some antibiotics, anti-inflammatory drugs, and anticonvulsants. If you suspect a medication is causing your rash, speak with your doctor or pharmacist before making any changes to your treatment.
Should I go to a walk-in clinic or emergency room for erythema multiforme?
For mild target-shaped lesions without eye, mouth, or fever symptoms, a visit to your family doctor or walk-in clinic is usually appropriate. However, if you have severe symptoms, blistering, eye involvement, or difficulty eating or drinking, go to the emergency room right away. Most provincial health plans in Canada cover these types of visits.
Key Takeaways
Erythema multiforme is a skin reaction that causes distinctive target-shaped lesions on the body.
The minor form is common and usually clears up within one to six weeks without treatment.
The major form (Stevens-Johnson syndrome) is rare but serious and requires emergency care.
Common triggers include the herpes simplex virus, certain medications, and bacterial infections like mycoplasma.
Treatment focuses on identifying and removing the trigger, and managing symptoms such as itching, mouth pain, and eye irritation.
Prevention relies on identifying and avoiding your personal trigger going forward.
If you develop a rash with fever, mouth sores, or eye symptoms, seek medical care right away through your family doctor, walk-in clinic, or emergency department.
Always consult a healthcare professional for a proper diagnosis and treatment plan.
