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Urticarial Vasculitis

Urticarial vasculitis is a subset of vasculitis characterized clinically by urticarial skin lesions and histologically by necrotizing vasculitis. Immune complex deposition (a type II immune complex reaction) in the postcapillary venules is the probable cause. There is a spectrum of clinical and laboratory features.

Many patients have minimal signs or symptoms of systemic disease. Systemic symptoms include angioedema (42%), arthralgias (49%), pulmonary disease (21%), and abdominal pain (17%). Thirty-two percent have hypocomplementemia, 64% have lesions that last more than 24 hours, 32% have painful or burning lesions, and 35% have lesions.

Urticarial plaques in most patients with typical chronic urticaria resolve completely in less than 24 hours and disappear while new plaques appear in other areas. Urticarial vasculitis plaques persist for 24 to 72 hours and may have residual changes of purpura, scaling, and hyperpigmentation. The lesions are burning and painful rather than itchy.  


Biopsy shows a histologic picture that is indistinguishable from that seen in cutaneous necrotizing vasculitis (palpable purpura). Fragmentation of leukocytes and fibrinoid deposition occur in the walls of postcapillary venules, a pattern called leukocytoclastic vasculitis. There is an interstitial neutrophilic infiltrate of the dermis. Anti-C1q autoantibody develops in disorders.

Patients with hypocomplementemia may have an immunofluorescent pattern of immunoglobulins or C3 as determined by routine direct immunofluorescence. As with typical cutaneous vasculitis, most patients have an elevated erythrocyte sedimentation rate. Patients with more severe involvement have hypocomplementemia (hypocomplementemic urticarial vasculitis syndrome) with depressed CH50 , C1q, C4, or C2. Direct immunofluorescence in patients with hypocomplementemia shows deposition of Ig and C3; 87% have fluorescence of the blood vessels, and 70% have fluorescence.


Prednisone in dosages exceeding 40 mg/day.

Other medications reported to be effective are indomethacin (25 mg three times daily to 50 mg four times daily), colchicine (0.6 mg two or three times daily), dapsone (up to 200 mg/day), low-dose oral methotrexate.