[Spectrum of morphological changes in chronic spontaneous urticaria and urticarial vasculitis].

The prevalence of chronic spontaneous urticaria (CSU) in the population is 0.5%-1%. According to modern guidelines for the management of patients with urticaria, the diagnosis of CSU does not require histological examination. However, in controversial clinical setting requiring differential diagnosis with urticarial vasculitis (UV), pathologists discover a wide range of pathomorphological changes in skin preparations in the absence of generally accepted differential diagnostic criteria. In this connection, it is of interest to study the spectrum of morphological changes in chronic spontaneous urticaria and urticarial vasculitis.

Objective: To analyze morphological changes in CSU and UV to improve differential diagnosis in clinical practice.

Material and methods: The material of 15 patients with urticarial rashes was analyzed. Comparative analysis of the number of neutrophils and mast cells in skin samples from patients with chronic spontaneous urticaria and urticarial vasculitis was performed.

Results: The material of 15 patients with urticarial rashes was analyzed. The group of patients with CSU (n=5) was characterized by the absence of signs of leukocytoclastic vasculitis; endothelial cells and mild of moderate swelling were visualized in all samples, the perivascular infiltrate was located in the upper layer of the dermis and was sparse. And when stained with toluidine blue, a large number of mast cells were noted. In the group of patients with UV (n=10), signs of leukocytoclastic vasculitis of varying severity, dense and deep perivascular neutrophilic infiltrates with a small number of mast cells were visualized.

Conclusion: Considering the wide range of morphological changes in the skin in CSU and UV, for the differential diagnosis of diseases, a comprehensive histological examination of preparations in combination with an assessment of the number of mast cells in the dermis and an assessment of the composition of the cellular infiltrate for the number of neutrophils can be recommended.