Erythema Multiforme - Symptoms, Causes & Treatment
By ScanSkinAI Editorial Team✓ Reviewed for medical safetyLast updated June 2026
An immune-mediated skin condition characterized by distinctive target-shaped lesions. It's usually triggered by infections, particularly herpes simplex virus, or medications. The condition ranges from mild to severe.
Concerned this might be erythema multiforme? Scan it with our AI skin checker for instant analysis, or use our AI mole checker for pigmented lesions. Browse all 80+ skin conditions in our directory.
Quick Answer
Erythema multiforme is a skin reaction that causes distinctive, target-shaped or bullseye spots to appear, often starting on the hands and arms. It is typically triggered by an infection, particularly the herpes simplex virus (cold sores), or sometimes as a reaction to certain medications. Most cases are mild, clear up independently within a few weeks, and only cause mild itching or burning. However, if the rash spreads to the mucous membranes of your mouth, eyes, or genitals, it is considered more severe and requires prompt medical attention.
Clinical Context
Erythema multiforme (EM) is an acute, self-limited, immune-mediated condition. EM minor affects only the skin and is most commonly triggered by herpes simplex virus (HSV). EM major involves mucous membranes and may overlap with Stevens-Johnson syndrome. The characteristic three-zone target lesion is pathognomonic. Recurrent EM is usually HSV-related, and prophylactic antiviral therapy can prevent episodes.
Symptoms
- Target-like or bullseye lesions with three zones
- Symmetric distribution on extremities
- Lesions appear over 3-5 days
- Mild itching or burning
- May have oral lesions (EM major)
- Low-grade fever and malaise in some cases
Severity & Progression
Causes & Risk Factors
- Herpes simplex virus types 1 and 2 (most common cause)
- Mycoplasma pneumoniae infection
- Medications (sulfonamides, penicillins, NSAIDs, anticonvulsants)
- Other infections (fungal, viral)
- Vaccination (rare)
Treatment & Management
EM minor is self-limiting and typically resolves in 2-4 weeks without scarring. Treatment is supportive: symptomatic relief with antihistamines and topical corticosteroids. EM major may require systemic corticosteroids and supportive care for mucosal lesions. For HSV-associated recurrent EM, prophylactic antiviral therapy (acyclovir, valacyclovir) can prevent episodes. Stop any suspected causative medication.
- Symptomatic relief (antihistamines, topical corticosteroids)
- Stopping suspected causative medications
- Treatment of underlying infection
- Prophylactic antivirals for HSV-related recurrent EM
- Systemic corticosteroids for severe cases
- Supportive care for mucosal involvement (mouthwashes, eye drops)
Red Flags & Complications
Seek medical attention if you experience any of the following:
- Post-inflammatory hyperpigmentation
- Mucosal scarring (EM major)
- Eye complications (conjunctivitis, corneal ulceration)
- Recurrence (especially HSV-associated)
- Very rarely, progression to more severe drug reactions
Self-Care Tips
- Apply cool compresses to lesions
- Use fragrance-free moisturizers
- For oral lesions: soft diet, avoid acidic foods
- Maintain good oral hygiene
- Monitor for signs of mucosal involvement
When to See a Doctor
If you develop widespread rash with fever, if mouth, eyes, or genitals are affected, or if lesions are painful or blistering
Frequently Asked Questions
What does an erythema multiforme rash look like?
The classic sign is a rash of target-shaped or bullseye lesions. These spots uniquely feature three distinct colour zones, often with a darker centre that might blister, surrounded by a paler ring and a red outer border. They usually appear evenly on your arms and legs over a few days and may cause mild itching or burning.
Why did I get this bullseye rash?
Erythema multiforme is an immune system reaction, most commonly triggered by an infection. The leading cause is the herpes simplex virus, which causes cold sores. It can also be triggered by a respiratory infection like mycoplasma pneumonia, or serve as an allergic reaction to certain medications, including antibiotics, pain relievers, or anti-seizure drugs.
How do you treat erythema multiforme?
Mild cases often resolve on their own within two to four weeks without leaving scars. Treatment focuses on relieving symptoms using antihistamines, cool compresses, and topical steroid creams to reduce itching. If a medication caused the rash, your doctor will advise you to stop taking it. For severe cases, oral steroids or other supportive treatments might be necessary.
Will this rash keep coming back?
Most people only experience a single episode that clears up completely. However, if your rash was triggered by the herpes simplex virus, it can reoccur alongside future cold sore outbreaks. If you experience frequent, recurring episodes of erythema multiforme, your doctor may prescribe daily antiviral medication to help prevent both the herpes outbreaks and the resulting skin reaction.
When is this rash considered an emergency?
You should seek medical attention immediately if the rash spreads to your mucous membranes, such as inside your mouth, eyes, or genitals. This indicates a more severe form of the condition called erythema multiforme major, which can cause significant pain, difficulty eating, and eye complications. Any rash accompanied by a high fever, extreme fatigue, or spreading blisters requires urgent medical evaluation.
Is erythema multiforme contagious?
No, the rash itself is absolutely not contagious. It is an internal immune system reaction, so you cannot catch erythema multiforme from someone else, nor can you pass the rash onto others. However, if your breakout was triggered by an active viral or bacterial infection, such as the cold sore virus or a respiratory bug, the underlying infection might be contagious.
What can I do at home to help my skin heal?
For skin comfort, you can apply cool, damp compresses to the affected areas and regularly use a gentle, fragrance-free moisturiser. Avoid scratching the lesions. If you have mild sores in your mouth, stick to a soft, bland diet and avoid spicy, salty, or acidic foods that might sting. Always maintain good oral hygiene, and ask a pharmacist about soothing mouthwashes.
How can ScanSkinAI help with a target-shaped rash?
ScanSkinAI can help you examine unusual target-shaped spots by comparing your photographs against a database of typical skin conditions. It serves as a helpful screening aid to categorise your symptoms and guide your next steps. However, our AI cannot medically diagnose erythema multiforme or any other condition. Always consult a healthcare professional for a formal diagnosis and appropriate treatment plan.
Related Conditions
Medical References
Information on this page is sourced from and verified against reputable medical resources:
Concerned About Your Skin?
Upload a photo and get instant AI-powered analysis across 80+ skin conditions. Track your condition over time with photo timelines, or use our dedicated AI mole checker for moles and pigmented lesions.
Medical Disclaimer: This information is for educational purposes only and is not intended as medical advice. The content on this page should not be used to diagnose or treat any health problem. Always consult with a qualified healthcare professional for proper medical evaluation, diagnosis, and treatment of your condition.