URTICARIAL VASCULITIS is a form of leukocytoclastic vasculitis defined clinically by urticarial wheals that tend to be painful or to cause a burning sensation, last longer than 24 hours, and resolve with purpura. It is often associated with hypocomplementemia and autoimmune disorders, primarily systemic lupus erythematosus. Those patients with serum hypocomplementemia in particular are more likely to have an associated autoimmune disease. The course of the disease is often chronic and must be differentiated from chronic urticaria. Histologically, urticarial vasculitis shows evidence of small vessel damage, including endothelial swelling, necrosis, and fibrin deposition.1 These histologic changes characteristically evolve as the lesions develop thus making this disease a suitable model for the study of the early changes in leukocytoclastic vasculitis.
Mehregan DR, Gibson LE. Pathophysiology of Urticarial Vasculitis. Arch Dermatol. 1998;134(1):88-89. doi:10.1001/archderm.134.1.88