Erythema Multiforme: Causes, Symptoms, Treatment, Complications and Outlook

It refers to any abnormal redness of the skin.

Erythema is caused by dilation and irritation of superficial capillaries; the increased blood flow through them imparts a reddish tone to the skin.

Flushing is a short form of erythema.

From the medical point of view, the main erythemas are photosensitive, multiform, and nodose erythema.

An erythema reaction can involve damage to the tissues and blood vessels of the skin.


The causes of erythema multiforme are:


Viral infection often causes this disorder, usually the herpes simplex virus (cold sore).


The cold sore virus remains inactive and tends to be reactivated by specific triggers.

This explains why the erythema can burst repeatedly.

Children with erythema usually develop cold sores a few days before the rash begins.

Infectious diseases:

The second most common trigger is an infection caused by bacteria associated with Mycoplasma pneumonia and other fungal infections.

Interaction with medications:

Medications can sometimes trigger the most severe type of erythema.

This rare form of the disease is much more powerful and sometimes life-threatening.

It is usually caused by a reaction to medications instead of an infection.

Medicines that can cause erythema multiforme include:

  • Antibiotics based on penicillin such as amoxicillin and ampicillin.
  • Anticonvulsants used for the treatment of epilepsy, such as phenytoin and barbiturates.
  • The sulfonamides.
  • The tetracyclines.
  • Non-steroidal anti-inflammatory drugs.


It is believed that erythema multiforme is a complex of symptoms secondary to many underlying disease states.

It can run a severe course and become a threat to life; the rash is prone to recur in mild cases.

The following are the most common symptoms of erythema multiforme:

  • Fever, headache, and malaise.
  • Eyes injected in blood, or dry can cause a burning, itching, and tearing sensation.
  • Sensitivity to light and blurred vision.
  • Canker sores inside the mouth, making it difficult to eat and drink.
  • Swollen lips covered with scabs.
  • Skin itch.
  • Joint pains
  • Fatigue.
  • Sudden and red patches and blisters.

The symptoms of erythema multiforme may resemble other skin conditions.


The goal of treatment is to control the disease that is causing the erythema, prevent infections and manage the symptoms.

Symptoms can be treated with:

  • Antihistamines to control itching.
  • Wet compresses for the skin.
  • Antiviral treatments if the cause is a herpes simplex infection, such as acyclovir.
  • Anesthetic mouthwash relieves the discomfort of sores in the mouth.
  • Steroid cream for inflamed skin.
  • Analgesics for pain.
  • Liquid diet if the mouth is significantly affected.
  • Drops for the eyes or ointment for the eyes.
  • Intravenous immunoglobulin.
  • Stop any medication that is causing the disorder.

The specific treatment for erythema multiforme will be determined by your doctor based on the following:

  • Age, general state of health, and medical history.
  • The severity of the condition.
  • The stage of the condition
  • Tolerance to specific medications, procedures, or therapies.

Erythema is not very serious and usually goes away with medications to control infection or inflammation.

However, if a person develops a more severe form of erythema, the condition can be fatal.

Erythema multiforme is known as Stevens-Johnson syndrome and is caused by a reaction to some medication.


Possible complications include:

  • Systemic infections or sepsis.
  • With the loss of body fluids and septic shock, blood pressure drops dangerously low.
  • Permanent damage to the skin with scars.
  • Infections on the skin ( cellulitis ).
  • Permanent damage to the eyes.

Occasionally, the internal organs may be affected, causing inflammation of the heart ( myocarditis ), lungs ( pneumonia ), kidneys (nephritis), or liver (hepatitis).


Mild cases of erythema usually improve in two or three weeks with simple lotions or cream based on steroids, but the disease can return, usually when the cause is the herpes simplex virus.

If this is the case, you may be prescribed a small daily dose of medication to suppress the herpes simplex virus for several months.

The most severe cases can take up to six weeks to improve.

Some people have scars on their skin after the rash clears, and vision can be damaged if the eyes have been affected.