Erythema Multiforme (EM)

Acute mucocutaneous hypersensitivity reaction of variable severity characterized by symmetrical skin eruptions, with or without mucous membrane lesions.

(Figure)

(Figure)

(Figure)

(Figure)

Erythema Polyforme (French appellation); EM.

EM minor form or EM major form (Stevens-Johnson syndrome).

The terminology of the disorder is confusing, and the many names represent the spectrum of one disease that is part of mucocutaneous syndromes. Historically, erythemas were first described by Willan in 1808, but the fact that they are different clinical presentations of the same entity was first noted by Hebra in 1860. Then, in 1916 Rendu described mucosal lesions with or without skin lesions, which were later named “ectodermosis erosiva pluriorificialis" by Fiessinger in 1923. Meanwhile, in 1922 the American and English literature reported the association of skin and mucosal lesions with a systemic reaction, the Stevens-Johnson syndrome. The common nature of all these conditions was noticed in 1965 by Ströhm, who gave them the term “mucocutaneous fever.” Currently, this entity is considered an immunologic disease that may be linked to the presence of HLA-B15.

The reported incidence of EM is 0.03 to 0.1% in the general population. Males are affected more often than females (ratio of 3:1). The majority of cases occur in individuals younger than 20 years. The disease is almost nonexistent in those younger than 3 years and older than 50 years. The disease is recurrent in approximately 30% of cases. The incidence of drug-related cases of EM major is equal in males and females.

Not a genetic disorder, although a genetic predisposition has been discussed.

Can be caused by drugs (nonsteroidal antiinflammatory drugs (e.g., ibuprofen, naproxen, valdecoxib, oxaprozin), sulfonamides, penicillins, cephalosporins, erythromycin, tuberculostatics, salicylates, pyrazolones, carbamazepine, phenobarbital, phenytoin), viral (e.g., adenovirus, herpes simplex virus, Epstein-Barr virus, cytomegalovirus, hepatitis A and B virus, measles virus, varicella virus, mumps virus, influenza virus, coxsackie virus B5), bacterial (e.g., Proteus species, Salmonella species, Mycobacterium species, Brucella species, Corynebacterium diphtheriae), fungal (e.g., histoplasmosis), parasitic (e.g., coccidiosis) or mycoplasma infections, endocrine factors, neoplasms, ...