[Neutrophilic urticaria or urticaria with predominantly neutrophilic inflammatory infiltrate: study of its clinical and histopathologic characteristics and its possible association with rheumatic disease].

INTRODUCTION Neutrophilic urticaria, described by Winkelmann in 1985, has yet to be completely defined and its clinical significance is poorly understood. Nevertheless, recent publications suggest that it could be a marker for rheumatic disease. The primary objective of this study was to compare the prevalence of rheumatic disease in 2 groups of patients with urticaria: those with conventional urticaria (non-neutrophilic inflammatory infiltrate) and those with neutrophilic urticaria. MATERIAL AND METHODS We retrospectively reviewed all biopsy samples taken from urticarial lesions in our hospital between January 1, 1999 and June 28, 2009. Urticaria was classified according to predefined morphologic and histopathologic patterns. We compared the clinical and histologic characteristics of neutrophilic urticaria with those of conventional urticarias in the 84 patients included. RESULTS Of the 84 patients, 57.1% had neutrophilic urticaria. We did not find significant differences between the percentages of patients with rheumatic disease between the neutrophilic and nonneutrophilic urticaria groups. In patients with acute urticaria, we found a significantly higher proportion of samples with histopathologic signs of neutrophilic urticaria as opposed to conventional histopathology. Patients with neutrophilic urticaria also had higher white blood cell counts. CONCLUSIONS The percentage of samples with neutrophilic urticaria in this series (57.1%) is higher than the percentages reported in the literature, possibly because we tended to biopsy recent lesions. We highlight that the presence of neutrophils in the biopsies of urticaria is a common finding and does not appear to be associated with other diseases.