National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Erythema multiforme



Other Names:
EM; Erythema polymorphe, erythema multiforme type; Erythema multiforme bullosum; EM; Erythema polymorphe, erythema multiforme type; Erythema multiforme bullosum; Dermatostomatitis, erythema multiforme type; Febrile mucocutaneous syndrome; Herpes iris, erythema multiforme type See More
Categories:

Erythema multiforme (EM) refers to a group of hypersensitivity disorders characterized by symmetric red, patchy lesions, primarily on the arms and legs. The cause is unknown, but EM frequently occurs in association with herpes simplex virus, suggesting an immunologic process initiated by the virus. In half of the cases, the triggering agents appear to be medications, including anticonvulsants, sulfonamides, nonsteroidal anti-inflammatory drugs, and other antibiotics. In addition, some cases appear to be associated with infectious organisms such as Mycoplasma pneumoniae and many viral agents. Erythema multiforme is the mildest of three skin disorders that are often discussed in relation to each other. It is generally the mildest of the three. More severe is Stevens-Johnson syndrome. The most severe of the three is toxic epidermal necrolysis (TEN).[1]
Last updated: 11/14/2011

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Erythema multiforme. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease


These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • DermNet NZ is an online resource about skin diseases developed by the New Zealand Dermatological Society Incorporated. DermNet NZ provides information about this condition.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Erythema multiforme. Click on the link to view a sample search on this topic.

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  1. Erythema multiforme. National Organizations for Rare Disorders (NORD). 2005; http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/280/viewAbstract. Accessed 11/14/2011.