Introduction -- Risk factors for extremity ulcer -- Pathogenesis of extremity ulcer -- Common lower limb ulcers -- Approach to uncommon lower limb ulcer -- Hypertensive ulcer -- Rheumatoid ulceration -- Necrobiosis lipoidica -- Systemic sclerosis -- Livedoid vasculopathy -- Warfarin-induced skin necrosis -- Heparin-induced necrosis -- Coagulopathy -- Cholesterolembolism -- Septic emboli -- Calciphylaxis -- Cryofibrinogenaemia -- Cryoglobulinaemia -- Levamisole-adulterated cocaine vasculopathy -- Tropical ulcer -- Buruli ulcer -- Lepromatous ulcer -- Lupus vulgaris -- Dermal leishmaniasis -- Fungal infection & foot ulcer -- Extravasation ulcers following chemotherapy -- Tubercular ulcers -- Amoebic ulcers -- Diathermy burn ulcers -- Covid related ulcers -- Neuropathic ulcers -- Drug induced ulceration.