Urticarial vasculitis (UV) is considered a clinicopathologic entity consisting of two elements:
●Clinical manifestations of urticaria
●Histopathological evidence of cutaneous leukocytoclastic vasculitis (LCV) of the small vessels, largely involving the postcapillary venules [1-4]
UV may predominantly involve the skin or affect other organ systems . Hypocomplementemia, when present, may be associated with extensive vasculitis and systemic features that most commonly involve the musculoskeletal, pulmonary, renal, and/or gastrointestinal systems. Although UV is most commonly idiopathic, it can occur in association with autoimmune diseases, drug reactions, infections, or malignancy. Discussion of UV is confounded by the lack of accepted criteria for distinguishing UV from other cutaneous vasculitides and associated conditions.
The epidemiology, clinical features, laboratory and biopsy findings, differential diagnosis, treatment, and prognosis of UV are reviewed here. A more general discussion of urticaria and related conditions is presented elsewhere. (See "Chronic urticaria: Clinical manifestations, diagnosis, pathogenesis, and natural history".)