skin disorders
Erythema Multiforme
Introduction
Erythema multiforme is an inflammatory skin disorder characterized by patches of red, raised skin that often look like targets and usually are distributed symmetrically over the body. (See also Overview of Hypersensitivity and Reactive Skin Disorders .) Erythema multiforme is usually caused by a reaction to an infection, usually herpes simplex virus. Typical symptoms include red patches with purple-gray centers (target lesions) that suddenly appear on the palms and soles, arms and legs, and face and may later spread to the body. Many people have mouth sores. The diagnosis is by a doctor's recognition of the target lesions. This disorder resolves without treatment, but symptoms can be treated with corticosteroids, antihistamines, and anesthetics applied to the skin. If people have frequent attacks and the doctor thinks herpes simplex virus is the cause, an antiviral drug may help prevent recurrences. Most cases are caused by a reaction to infection with the Herpes Simplex Virus (HSV) Infections . Some people with erythema multiforme develop herpesvirus cold sores on their lips several days before an attack of erythema multiforme. Less often, cases are caused by bacterial infections (such as Mycoplasmas ), drugs, vaccines, infections with other viruses (especially Doctors are unsure exactly how erythema multiforme happens, but a type of immune reaction is suspected. Some cases of erythema multiforme do not have a clear cause. Attacks of erythema multiforme may last 2 to 4 weeks. Some people have only one attack, but some have multiple recurrences. Recurrences are common, especially when the cause is herpes simplex virus. The frequency of recurrence usually decreases with time. 