label: Acute Erythema Nodosum
label_lc: acute erythema nodosum
description: A septal panniculitis characterized by the sudden onset of painful, firm, erythematous nodules or plaques that most commonly erupt on the pretibial extensor surfaces. Though generally idiopathic and self-limited, this disorder may be a sign of a co-morbid systemic disease or the sequela of the use of certain medications.