Erythema nodosum (EN) is a delayed-type hypersensitivity reaction that most often presents as erythematous, tender nodules on the shins (picture 1A-D). Common triggers for EN include infection, drugs, pregnancy, malignancy, and inflammatory conditions, such as sarcoidosis or gastrointestinal diseases; however, many cases are idiopathic (table 1). Erythema nodosum migrans (subacute nodular migratory panniculitis, migratory panniculitis): asymmetrical, unilateral and distributed solely on the legs; marked female predominance; older age group Chronic erythema nodosum : nodules appear over months / years; otherwise indistinguishable from typical condition Erythema nodosum (EN) is a common acute nodular septal panniculitis, characterized by the sudden onset of erythematous, firm, solid, deep nodules or plaques painful on palpation and mainly localized on extensor surfaces of the legs. These nodules are characterized by a typical histological appearance regardless of the etiology, marked by acute inflammation of the dermo-hypodermic junction and interlobular septa of the hypodermic fat, evolving without necrosis or sequelae.[1][2][3] Erythema nodosum is a skin condition that causes tender, red bumps on the shins or other parts of the body. It may be a reaction to an infection, medicine, or pregnancy. Learn how to diagnose and treat this condition from Johns Hopkins Medicine.
