Erythema nodosum

    Clinical Features:

    • A hypersensitivity reaction pattern that occurs secondary to multiple causes, including gastrointestinal, fungal and other infections; inflammatory bowel disease; sarcoidosis; oral contraceptive pills; malignancy and certain drugs.
    • Female predominance with a peak age between 20 and 30 years
    • Acute onset of tender bright red nodules, most commonly on the anterior shins, resolving in a few weeks

    Histologic Features:

    • Septal panniculitis comprised mainly of neutrophils, often with some admixed lymphocytes and eosinophils
    • The septa also display some degree of edema and/or hemorrhage.
    • The inflammation extends into the adjacent periphery of the fat lobules, but the lobules are otherwise largely unaffected.
    • Older lesions show thickening of the septa with a predominantly mononuclear infiltrate progressing to eventual granulomatous inflammation and greater involvement of the lobules.
    External Links:

     

    Cases associated with this book:

  • Erythema nodosum
    Author: Artur Zembowicz M.D. Ph.D.

    Conference: DermatopathologyConsultations.com Teaching Collection
  • Erythema nodosum
    Author: Stephen Lyle, M.D., Ph.D.

    Conference: DermatopathologyConsultations.com Teaching Collection