Erythema multiforme is a skin disorder resulting from an allergic reaction .
Alternative Names
Lyell's syndrome; Stevens-Johnson syndrome; Toxic epidermal necrolysis
Causes, incidence, and risk factors
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. The exact cause is unknown. The disorder is believed to involve damage to the blood vessels of the skin with subsequent damage to skin tissues. Approximately 90% of erythema multiforme cases are associated with herpes simplex or Mycoplasma infections. The disorder occurs primarily in children and young adults. Erythema multiforme may present with a classic skin lesion with or without systemic (whole body) symptoms. In Stevens-Johnson syndrome, the systemic symptoms are severe and the lesions are extensive, involving multiple body areas (especially the mucous membranes). Toxic epidermal necrolysis (TEN syndrome, or Lyell's syndrome) involves multiple large blisters ( bullae ) that coalesce, followed by sloughing of all or most of the skin and mucous membranes.
Signs and tests
Positive Nikolsky's sign The diagnosis is primarily based on the classic skin lesion appearance and typical symmetrical distribution, especially if there is a history of risk factors or associated diseases. A skin lesion biopsy and microscopic examination may be helpful to differentiate erythema multiforme from other disorders. Erythema multiforme may show keratinocyte necrosis (tissue death) and other changes. Microscopic examination of the tissue may also show deposits of immune complexes ( antibody deposits).
Treatment
Treatment goals include control of the underlying causes or illnesses, treatment of the symptoms, and prevention of infection. Suspected medications should be discontinued.
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.
Topical anesthetics (especially for mouth lesions ) to ease discomfort that interferes with eating and drinking. Treatment of severe symptoms may include:
Hospitalization and treatment in an intensive care or burn care unit for severe cases, Stevens-Johnson syndrome, and toxic epidermal necrolysis Systemic corticosteroids to control inflammation Intravenous immunoglobulins (IVIG) to stop the process Antibiotics to control secondary skin infections Good hygiene and isolation from others may be required to prevent secondary infections . Extensive skin involvement may cause the loss of large quantities of body fluids, causing shock in addition to the risk of infection. Intensive care with support of body systems may be required. Skin grafting may be helpful in cases in which large areas of the body are affected.
Expectations (prognosis)
Mild forms of erythema multiforme usually resolve without difficulty in 2 to 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.
Calling your health care provider
Go to the emergency room or call the local emergency number (such as 911) if symptoms indicate erythema multiforme. Involvement of a large area of the body is an emergency situation.