A benign subcutaneous tumor composed of fat and blood vessels that is characteristically tender to palpation.
An autoimmune disorder that can cause livedo reticularis, purpura, and painful, 'punched-out' ulcerative lesions on the legs due to thrombosis.
A condition leading to intensely painful, violaceous, retiform purpura that progresses to necrotic ulcers with black eschars, typically in patients with renal failure.
Can present as a chronic, verrucous (wart-like) or ulcerative nodule on the leg that fails to heal.
Common in diabetics, presenting as multiple, asymptomatic, reddish-brown, atrophic, scar-like macules on the shins ('shin spots').
A benign sweat gland tumor, often on the sole of the foot, presenting as a solitary, moist, red, often pedunculated nodule.
A lobular panniculitis, often associated with tuberculosis, presenting as tender, violaceous nodules on the posterior lower legs (calves) that frequently ulcerate.
A septal panniculitis presenting as the sudden onset of tender, erythematous, non-ulcerating subcutaneous nodules on the anterior lower legs (shins).
A vascular tumor that presents as distinctive violaceous or brown patches, plaques, or nodules, which are common on the lower extremities.
A panniculitis associated with lupus, presenting as firm, deep, subcutaneous nodules that heal with a characteristic depressed, atrophic scar.
Inflammation of subcutaneous fat associated with pancreatic disease, presenting as tender nodules that can ulcerate and discharge an oily, necrotic substance.
A medium-vessel vasculitis that can cause tender, subcutaneous erythematous nodules, livedo reticularis, and 'starburst' purpura along the course of an artery.
Can present as infiltrated, violaceous or reddish-brown plaques and nodules (Darier-Roussy sarcoid) on the legs.
An eczematous rash on the lower legs caused by chronic venous insufficiency, with associated edema, reddish-brown discoloration (hemosiderin), and lipodermatosclerosis.
Inflammation of a superficial vein, presenting as a tender, linear, erythematous cord on the leg.
Inflammation of small blood vessels causing characteristic palpable purpura (non-blanching red/purple spots) on the lower legs.