Superficial epithelial necrosis ranging toward full-thickness tissue destruction.
Color: brown, black.
Size: mm to cm.
May involve any area of skin.
Favours areas served by a terminal vessel with few collaterals.
May develop into ulcer.
Heals with atrophy or scarring.
Comment / Explanation
Secondary infections possible.
May follow: venous leg ulcer, peripheral arterial occlusion, diabetic foot ulcer, deep thermal or chemical burn (3°), deep infections, tumors, autoimmune vasculitis, cryoglobulinemia and cold agglutinins.
Site of entry for anthrax, rickettsial diseases (eschar).
Massive tissue destruction through: tumor outgrowing its vascular supply, infection, obstructive vascular disease, late stage Raynaud.
Trauma: extensive damage.
Exogenous noxious agents: chemicals (acids or bases), burns, frost bite.