• The image depicts deep dermal tissue with inflammatory cells in a perivascular location, between collagen bundles.
•Believed to be a hypersensitvity reaction to varied
•The precise cause of erythema nodosum is unknown, but it can often occur as a sequel to bacterial infections, in response to some drugs and accompanying some fungal infections.
•It characterisically presents as an exquisitely
tender, erythematous lesion.
•Erythema nodosum is usually self-limiting.
•Any underlying associated diseases are treated.
|General Gross Description|
•Erythema nodosum is one form of acute inflammation of
the soft tissue of the skin (panniculitis).
•The lesion is often not clearly visible, but can palpated as an area of induration in the subcutaneous tissues.
|General Micro Description|
•Histologically, there are two patterns.
•If the inflammation primarily involves the septa
separating the subcutaneous adipose tissue into lobules,
there is some thickening of these septa with the
presence of inflammatory cells.
•If the inflammation attacks primarily the nodules of fat, areas of fat necrosis with accumulation of inflammatory cells and macrophages is seen.
•Robbins and Cotran: Pathologic Basis of Disease, 7th ed., 2005, p. 1265.