[Immunopathology in 35 cases of chronic urticaria].

Although urticaria is usually held to be a type 1 hypersensitivity reaction, it may also be the cutaneous manifestation of vasculitis mediated by immune complexes. In this study of 35 patients with chronic urticaria, the authors attempted to specify the prevalence of vasculitis and its possible correlations with particular clinical and/or immunological findings. In 10 cases, lymphocyte subpopulations were also studied, using monoclonal antibodies. Patients included 21 women and 14 men, aged 19 to 80. In each patient: a) systemic signs were looked for by history taking and physical examination; b) a skin biopsy was examined by optic microscopy and direct immunofluorescence; c) the following biological investigations were done: blood count, sedimentation rate, protein electrophoresis and immunoelectrophoresis, IgE, B virus markers, circulating immune complexes, anti-nuclei and anti-ADN antibodies, latex and Waaler-Rose tests, total complement, C3, C4, and C1 esterase inhibitor. Visceral involvement and various immunological disorders are most common in those patients with leukoclastic (n = 7) or mononuclear (n = 9) vasculitis. These patients, as well as those recently studied in the literature, have idiopathic chronic urticaria, the least severe of urticarial vasculitis.