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 nodosum, idiopathic


Other Names:
Idiopathic erythema nodosum; Erythema nodosum of unknown etiology
Categories:
Erythema nodosum (EN) is a skin condition in which red bumps (nodules) form on the shins. Less commonly, the nodules form on other areas of the body such as the thighs and forearms.[1][2] The lesions begin as firm, hot, red, painful lumps and progress to a purplish color.[1] EN is a type of inflammatory disorder affecting the layer of fat under the skin (panniculitis).[2][3] Other symptoms that may accompany the skin findings include the following: fever, a general feeling of being ill. joint aches, and swelling of the affected area.[1] In many cases, EN is presumed to be a delayed reaction to antigens associated with various infections, drugs, and certain systemic diseases.[3] In some cases, however, EN has no identifiable cause (idiopathic); in these cases, clinical follow-up is needed to rule out certain conditions including inflammatory bowel disease, sarcoidosis, lymphoma, and Behcet's disease.[3] Treatment may include rest, nonsteroidal anti-inflammatory drugs (NSAIDS), steroids, hot or cold compresses, potassium iodide solution, and supportive bandages or compression stockings.[1][2] Symptoms usually resolve within six weeks, but EN may become a chronic disorder lasting for months and, occasionally, for years.[1][2] Approximately 30% cases of idiopathic EN may last more than 6 months.[4]
Last updated: 9/24/2015

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.

Patient Registry

  • The Autoimmune Registry supports research for Erythema nodosum, idiopathic by collecting information about patients with this and other autoimmune diseases. You can join the registry to share your information with researchers and receive updates about participating in new research studies. Learn more about registries.

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 Providing General Support

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.

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 nodosum, idiopathic. Click on the link to view a sample search on this topic.

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  1. Erythema nodosum. MedlinePlus. October 18, 2013; https://www.nlm.nih.gov/medlineplus/ency/article/000881.htm. Accessed 9/24/2015.
  2. Erythema nodosum. DermNet New Zealand Trust. August 1, 2015; http://www.dermnetnz.org/vascular/erythema-nodosum.html. Accessed 9/24/2015.
  3. Shojania, Kaveh. Erythema nodosum. UpToDate. November 27, 2013; http://www.uptodate.com/contents/erythema-nodosum. Accessed 9/24/2015.
  4. Hebel, Jeanette. Erythema Nodosum. Medscape Reference. April 13, 2015; http://emedicine.medscape.com/article/1081633-overview. Accessed 9/24/2015.