Retiform purpura

etiform purpura is characterized by nonblanchable, hemorrhagic skin lesions caused by compromised blood vessels, leading to ischemia, necrosis, and subsequent leakage of red blood cells into the skin. 1 ''Retiform'' refers to the net-like appearance of the lesions, while ''purpura'' indicates the presence of extravasated red blood cells.The etiology includes thrombotic, vascular disruption, and metabolic causes.Thrombotic causes involve vascular occlusion leading to ischemia.Retiform purpura has been observed post-thrombectomy in COVID-19 patients, likely due to thrombotic vasculopathy (Figs 1 to 3).Disseminated intravascular coagulation causes widespread thrombosis, leading to profound purpura, violaceous necrosis, and ischemic damage, often in the setting of bacteremia (Figs 4 to 6 ).Arterial thrombosis, such as left external iliac artery occlusion, can also contribute (Fig 7).Vascular disruption following surgical interventions may result in localized ischemia.Retiform purpura can develop around surgical incisions post laparotomy due to vascular injury (Figs 8 and 9).Metabolic disorders, particularly calciphylaxis, lead to vascular calcification and thrombosis.Calciphylaxis, seen in uremic and nonuremic patients, results in severe retiform purpura with necrosis, ulceration, and inflammation (Figs 10 to 13). 2The healing process follows a distinct pattern.Lesions initially present as dusky plaques, progressing to necrotic plaques with central eschar and ultimately resolving with dissolving eschar (Figs 14 to 16).