Erythema multiforme is a rare skin condition characterized by targetoid lesions.
The most common sign of EM is the presence of a target lesions, although they may not always be present and variable mucous membrane involvement . EM minor presents as a mild to severe rash consisting of erythematous papules that are usually ranged symmetrically on the extremities and gradually enlarge. The typical lesions can develop a raised, edematous, pale ring and the outer edges will become a cyanotic or violaceous halo. After the inflammation resolves, hyperpigmentation or hypopigmentation can occur. Some affected individuals may experience pruritus and a burning sensation.
Laboratory tests are usually not required to confirm the presence of EM as a diagnosis is made clinically . Imaging studies are not needed in most cases either, although chest radiography can be useful if a patient has respiratory symptoms or an underlying pulmonary infection.
If the condition is considered to be severe, there may be specific tests conducted. Elevation of the erythrocyte sedimentation rate and leukocytosis may be present. Cultures including blood cultures, mucosal lesions cultures, and sputum cultures are also taken in these cases.
Before any treatment for EM can be done, the underlying cause of the disorder will need to be identified. If erythema multiforme is drug-induced, the offending medication must be withdrawn. If the cause is an infection, that condition should be treated first.
Symptomatic treatment includes oral antihistamines, analgesics, and mouthwashes . Various topical steroids can be used. If the eyes are affected, topical lubricants and supportive care can be used in treatment. Recurrent and severe forms require further treatment, frequently with continuous oral acyclovir.
In most cases EM is considered to be self-limited. The lesions that are associated with the minor form of EM usually resolve over two to three weeks without scarring . It is common for EM minor to recur especially in patients with a condition caused by the herpes simplex virus.
The more severe form, EM major, is associated with a mortality rate of under five percent. Mortality in relation to EM major is usually due to sepsis or penumonia. The associated lesions usually heal without scarring but they can cause postinflammatory hypopigmentation or hyperpigmentation and rarely scarring due to a secondary infection. Ocular involvement may lead to keratitis, conjunctival scarring, and visual impairment in rare cases.
The disorder is believed to be caused by a number of different factors that can vary from case to case . In about half of the reported cases of the disorder there is no one identifiable factor behind the occurrence of the EM and it is considered to be idiopathic. Certain medications such as antibiotics, anticonvulsants or antituberculoids can trigger the the disorder and bacterial, viral, parasitic and fungal infections are also a common cause of the condition. There are records of EM related to post-vaccinations including the Bacille Calmette-Guerin vaccination, the oral polio vaccine, and the tetanus/diphtheria vaccine. Erythema multiforme may also be associated with radiation, autoimmune diseases, and malignancies.
On an international scale EM is uncommon and the incidence is reported to be 00.1% to 1% of the population. Erythema multiforme occurs predominantly in adults between 20 and 40 years of age, although it can affect individuals of all ages. Men and women are equally affected.
It is believed that EM is an immunological disorder that results from a hypersensitive reaction triggered by various etiologic agents. However, the complete pathogenesis of erythema multiforme is not yet fully understood .
The pathogenesis of erythema multiforme due to herpes simplex virus has been investigated and is consistent with a delayed-type hypersensitivity reaction. It is however unclear, whether a similar mechanism is responsible for the development of the disorder related to other etiologic factors.
There may be a genetic predisposition in the development of EM. Especially HLA-DQB1*0301 was detected more frequently in patients with erythema multiforme. Other HLA types may play a role as well.
There is no way to prevent EM from occurring . When a person develops EM, it is important to figure out what triggered the disorder. This will allow them to better prevent recurrences.
Erythema multiforme (EM) is a self-limited, acute skin condition possibly mediated by of a type IV hypersensitivity that is associated with various infections or drug exposure . This disorder can vary in severity based on the affected person and can be triggered by different catalysts. EM is divided in two forms: Erythema multiforme minor and erythema multiforme major .
Erythema multiforme (EM) is a skin condition that is caused by various factors, but is mainly caused by a reaction to a medication, vaccine or infection. There are two forms of the disorder, a minor and a major form. Each form varies in intensity and can take anywhere from one week to six weeks to clear up. The minor form of EM is a slight skin disorder that clears up quickly while the major form of EM can be severe and, in some cases, life threatening. EM is characterized by lesions that look like targets. They appear on the extremities and inside of the mouth. The severity of the individual case will usually determine the type of medical treatment needed.