RT Book, Section A1 Hardin, J. Matthew A2 Knoop, Kevin J. A2 Stack, Lawrence B. A2 Storrow, Alan B. A2 Thurman, R. Jason SR Print(0) ID 1177132232 T1 Erythema Nodosum T2 The Atlas of Emergency Medicine, 5e YR 2021 FD 2021 PB McGraw-Hill PP New York, NY SN 9781260134940 LK accessemergencymedicine.mhmedical.com/content.aspx?aid=1177132232 RD 2021/01/21 AB Erythema nodosum (EN) can present at any age but is most common in young, adult females. Most typical is bilateral, erythematous, subcutaneous, tender nodules on the pretibial and lateral lower extremities (usually spares the posterior calves). Rarely, the nodules can be found on the thighs, upper extremities, and face. Concomitant symptoms include lower extremity edema and arthralgias. Systemic symptoms can include fever, headache, and gastrointestinal complaints. Generally, the nodules resolve over days to weeks with flattening and a change in color to a blue-green (like a deep bruise). There is no ulceration, and the skin slowly returns to normal. Recurrence occurs in up to one-third of cases.