Histopathological and clinical evaluation of chronic spontaneous urticaria patients with neutrophilic and non-neutrophilic cutaneous infiltrate

Background: Chronic urticaria has an expressive prevalence in general population, especially in adults, and is defined by the presence of intermittent hives for six weeks or longer. Our study aims to characterize the histological patterns of chronic spontaneous urticaria, based on the inflammatory cell infiltrate, and correlate them to laboratory exams. Methods: It was performed a retrospective analysis of laboratory, histopathology and direct immunofluorescence data of 93 patients with chronic urticaria. For histopathological analysis, cell count was performed in four fields at high magnification (×400) for each specimen. The resulting cell count medians were submitted to statistical analysis and, then, were correlated to laboratorial findings. Results: We found a female predominance (76.34%) of chronic urticaria cases, and an average age of 42.5 years (SD ± 15). Two histological groups were distinctive: 1) chronic urticaria with predominance of neutrophils or eosinophils – N (%) = 39 (42.4%) – and 2) chronic urticaria with predominance of lymphocytes – N (%) = 53 (57.6%). There was not significant correlation between histological groups and laboratorial tests. Moreover, direct immunofluorescence was positive in 21 (33,87%) from 62 patients. Conclusions: There is not enough scientific evidence to support neutrophilic urticaria as a solid, separate entity