User:Mr. Ibrahem/Erythema multiforme

Erythema multiforme (EM) is a skin condition that classically appears as target lesions. The skin or mouth can be involved. These come on over a couple of days and resolve within 3 to 6 weeks. Often they are most clearly seen on the palms and soles. Other symptoms may include fever and joint pain. Some have recurrent episodes.

The most common trigger is a herpes simplex (HSV) infection. Other triggers may include infections such as cytomegalovirus, Epstein-Barr virus, and SARS-CoV-2; medications such as NSAIDs, antibiotics, and vaccines; and other problems such as inflammatory bowel disease, leukemia, and other cancers. The underlying mechanism is believed to involve the immune system. Diagnosis is based on symptoms and may be confirmed by tissue biopsy. There are two types erythema multiforme minor and erythema multiforme major.

Treatment is generally supportive or based on the underlying trigger. In those with HSV sunscreen or valacyclovir may be used. In more severe cases corticosteroids, dapsone, or cyclosporine may be used. Outcomes are generally good.

Erythema multiforme is uncommon. It most commonly occurs in the second and third decades of life. Males are more commonly affected than females. It was first described by von Hebra in 1860.