[Cutaneous vasculitis].

Vasculitis is a term that refers to damage and inflammation of the walls of blood vessels of any size. The classification of types of cutaneous vasculitis continues to be a challenge, probably because of our lack of understanding of the etiology and pathogenesis of this condition. Changes in the vessel wall will be visible on microscopy and will enable the different clinical forms to be distinguished according to the caliber of affected vessels, the type of cell that predominates in the inflammatory infiltrate, or the presence of such key findings as extravascular granulomas. Skin manifestations (macules, papules, nodules, livedo reticularis, etc) correlate with the size of the vessel affected. The prognosis in cases of vasculitis with skin involvement will be determined by the presence or absence of extracutaneous disease. Systemic vasculitis shows a predilection for certain organs, such as the kidney or lung. The introduction of immunosuppressant drug treatments has led to evident improvement in survival rates for patients with vasculitis. This review covers practical aspects of the pathophysiology, histopathology, treatment, and differential diagnosis of the main clinical presentations of vasculitis with cutaneous involvement.