classic pyoderma gangrenosum
A rare subtype of pyoderma gangrenosum disease characterized by rapidly progressive, single or multiple, painful, aseptic ulcers which present overhanging, violaceous and undermined borders, surrounding induration and erythema, and granulation tissue (occasionally necrotic tissue and/or a purulent exudate) at the base, mainly affecting the legs (but other body surfaces may also be involved), leading to chronic ulcerations and often regressing with cribriform mutilating scars. The disease presents a chronic relapsing course and systemic features (e.g. fever, malaise, arthralgia, myalgia) may be associated.