Urticarial vasculitis: a histopathologic and clinical review of 72 cases.
BACKGROUND: Urticarial vasculitis is a subset of vasculitis characterized clinically by urticarial skin lesions and histologically by necrotizing vasculitis. OBJECTIVE: A review of patients with urticarial vasculitis was undertaken to further characterize the clinical and histologic findings and to differentiate this disorder from urticaria and other types of cutaneous vasculitis. METHODS: Seventy-two cases of biopsy-proven urticarial vasculitis were selected for a review of medical records, laboratory data, and histologic findings. Fifty cases of simple urticaria were also reviewed for purposes of comparison. RESULTS: Systemic symptoms in patients with urticarial vasculitis included angioedema in 30 patients (42%), arthralgias in 35 (49%), pulmonary disease in 15 (21%), and abdominal pain in 12 (17%). Twenty-three patients (32%) had hypocomplementemia. Forty-six of 72 patients (64%) had lesions that lasted more than 24 hours, 23 of 72 (32%) had painful or burning lesions, and 25 of 72 (35%) had lesions that resolved with purpura. Sixteen biopsy specimens from the 23 patients with hypocomplementemia showed dermal neutrophilia in addition to the perivascular infiltrate. Of the 23 patients with hypocomplementemia, 20 (87%) had fluorescence of the blood vessels and 16 (70%) had fluorescence of the basement membrane zone as determined by routine direct immunofluorescence. CONCLUSION: Patients with hypocomplementemia were more likely to have systemic symptoms such as urticaria that resolved with purpura, arthralgias, abdominal pain, and chronic obstructive pulmonary disease. The histologic pattern associated with hypocomplementemia is interstitial neutrophilic infiltrate of the dermis and an immunofluorescent pattern of immunoglobulins or C3 in the blood vessels and along the basement membrane zone.