A reassessment of diagnostic criteria and treatment of idiopathic urticarial vasculitis: a retrospective study of 47 patients.

Summary Background.  Urticarial vasculitis (UV) is an uncommon type of chronic urticaria (CU), which exhibits leucocytoclastic vasculitis. Painful and long-lasting (> 24 h) weals associated with purpura or bruising are considered indicative of UV. It is often responsive to oral corticosteroids and poorly to oral antihistamines. Hypocomplementaemia and systemic involvement are also commonly reported. Aims.  To diagnose patients with UV histologically and then compare their clinical features and response to various treatment regimens. Methods.  Biopsies were taken from 312 subjects with CU unresponsive to oral antihistamines; of these, 47 were histologically diagnosed as having UV. Biopsies were taken irrespective of the clinical features of weal eruption. Other diseases known to be associated with small-vessel vasculitis had previously been excluded. Results.  Individual weals lasted < 24 h in 57.4% of patients, and pain or tenderness was reported only by 8.6%. Extracutaneous features were present in 81%, hypocomplementaemia in 11% and abnormalities of other laboratory parameters (i.e. raised erythrocyte sedimentation rate, microscopic haematuria) in 76.6%. Hydroxyzine was effective in only one patient. Both oral corticosteroids and cinnarizine were effective in a high percentage of the patients. Conclusion.  This diagnostic approach allowed us to identify a large group (47 patients) with UV. Most did not present the clinical (prolonged duration of weals and bruising) and laboratory features that have previously been described as characteristic of UV. Cinnarizine was found to be a valuable treatment option.