Publisher Summary Vasculitis refers to inflammation and necrosis of blood vessels, whether they are arteries, veins or both. It can be local or systemic, and may be primary or secondary to another disease process. The classic cutaneous manifestation of vasculitis is palpable purpura; however, the clinical manifestation greatly depends on the size of the vessel affected. Leukocytoclastic vasculitis is a pathological description used to describe inflammation of post-capillary venules and is clinically more correctly termed “cutaneous small vessel vasculitis (CSVV).” CSVV occurs equally in both sexes and at all ages. It is estimated that 10% of affected patients are children. The histopathologic pattern is that of a leukocytoclastic vasculitis—angiocentric, segmental inflammation with nuclear dust, endothelial-cell swelling, and fibrinoid necrosis. The American College of Rheumatology (ACR) has proposed criteria for the diagnosis of hypersensitivity vasculitis, which corresponds to CSVV.