Erythema nodosum

Last updated: September 9, 2020

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Erythema nodosum (EN) is an inflammation of subcutaneous fat caused by a delayed hypersensitivity reaction. Women in early adulthood are commonly affected. Most cases are idiopathic, but an association with a variety of diseases, including infections and autoimmune disorders (e.g., ulcerative colitis), is possible. The characteristic lesions are painful nodules on the lower legs (particularly shins). EN is a clinical diagnosis. The condition typically heals spontaneously within a few weeks and, therefore, generally requires no more treatment than supportive care (e.g., analgesia).

Epidemiologytoggle arrow icon


Epidemiological data refers to the US, unless otherwise specified.

Etiologytoggle arrow icon


Pathophysiologytoggle arrow icon


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Diagnosticstoggle arrow icon


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  • Symptomatic treatment
  • Treat underlying disease
  • In severe or refractory cases: systemic steroids


Prognosistoggle arrow icon

  • Usually self-limiting (within 2–8 weeks), or resolves earlier with effective treatment of underlying disease
  • Recurrence following discontinued treatment is common


Referencestoggle arrow icon

  1. Hebel JL, James WD. Erythema Nodosum . Erythema Nodosum . New York, NY: WebMD. Updated: March 3, 2016. Accessed: June 7, 2017.
  2. Kroshinsky D, Callen J, Ofori AO, Romain PL. Erythema Nodosum. In: Post TW, ed. UpToDate. Waltham, MA: UpToDate. Last updated: November 30, 2016. Accessed: June 23, 2017.
  3. Paller AS, Mancini AJ. Hurwitz Clinical Pediatric Dermatology. Elsevier Health Sciences ; 2015
  4. Gupta M, Singh K, Lehl SS, Bhalla M. Recurrent erythema nodosum: a red flag sign of hidden systemic vasculitis. BMJ Case Rep. 2013.doi: 10.1136/bcr-2013-009507 . | Open in Read by QxMD

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