Causes

Erythema multiforme is a type of hypersensitivity (allergic) reaction that occurs in response to medications, infections, or illness. Medications associated with erythema multiforme include sulfonamides, penicillins, barbiturates, and phenytoin. Associated infections include herpes simplex and mycoplasma infections.

Erythema Multiforme is an allergic reaction caused by medications (eg sulfonamides, penicillins, barbiturates, phenytoin), infection (herpes simplex, mycoplasma) or illness. Roughly 90% of cases is due to herpes simplex or Mycoplasma infections and occurs mostly in children and young adults.

Symptoms

Erythema multiforme is a recurring disorder characterized by patches of red, raised skin that often look like targets and usually are distributed symmetrically over the body. Most cases are caused by a reaction to infection with the herpes simplex virus. Doctors are not sure if other infectious diseases also cause erythema multiforme. Doctors are unsure exactly how herpes simplex causes this disorder, but a type of immune reaction is suspected. Symptoms: Usually, erythema multiforme appears suddenly, with reddened patches erupting on the arms, legs, and face. Sometimes the rash is also present on the palms or soles.

How is it diagnosed?

Your health care provider will ask about your recent medical history, including what infections you have had and what medicines you have been taking. Your provider will ask about your symptoms and examine you.

Usually your health care provider can diagnose E. multiforme by looking at the rash. The only way to confirm the diagnosis is with a skin biopsy. If you have a biopsy, you will be given a numbing medicine and then your provider will remove a small piece of skin. The skin sample will be sent to a lab for tests.

How to Prevent

·Avoiding suspected causes where feasible.

·Prompt treatment of any illness or infection that may cause erythema multiforme.

·Prevention of herpes simplex virus outbreaks by avoiding sun exposure and reducing stress

Treatment

Treatment should focus on the underlying cause. Symptoms can be treated with bed rest, leg elevation, compressive bandages, wet dressings, and nonsteroidal anti-inflammatory agents.

Your physician based on will determine specific treatment for erythema nodosum depending on your age, overall health, and medical history, extent of the condition, your tolerance for specific medications, procedures, or therapies, expectations for the course of the condition and your opinion or preference.

Antiviral medications-if the outbreak is caused by herpes simplex, antiviral medications may be given to prevent a recurrence but is not effective to treat the rash already present. This is typically used for people with frequent outbreaks of erythema multiforme.

Treatment of mild symptoms may include:

·Moist compresses applied to skin lesions

·Medications such as antihistamines to control itching

·Over-the-counter medications (such as acetaminophen) to reduce fever and discomfort

Expectations (prognosis)

Mild forms of erythema multiforme usually resolve without difficulty in 2 - 6 weeks, but they may recur. More severe forms may be difficult to treat. Stevens-Johnson syndrome and toxic epidermal necrolysis are associated with high death rates.