Clinical and morphological characteristics of patients with urticarian rasches

BACKGROUND: The most common diagnosis given to patients with chronic urticarial rashes is chronic spontaneous urticaria (prevalence in the population is 0.1–1.4%). However, similar symptoms can also be observed in other rarer diseases: urticarial vasculitis, hypocomplementemic urticarial vasculitis syndrome, cryopyrine-associated syndromes and Schnitzler's syndrome.

AIM: to analyze the clinical features and histological characteristics of skin biopsies in patients with chronic urticarial rashes to optimize the management and improve differential diagnosis.

MATERIALS AND METHODS: At a retrospective stage, 9 patients with chronic urticarial rashes and a histological examination were selected from the archival data of the Clinic of Skin and venereal fiseases named after V.A. Rakhmanov Sechenov University from January 2019 to April 2022. Prospective patient recruitment was from January 2022 to September 2023 and included 11 patients who underwent skin biopsy. Data obtained from the analysis of demographic characteristics are presented as median and interquartile range. Histological parameters were assessed by qualitative and quantitative methods.

RESULTS: The study included 20 patients (16 women and 4 men) aged 23 to 63 years, 36.5. Depending on the clinical and histological characteristics, the patients were divided into three groups: 9 patients with chronic spontaneous urticaria, disease duration from 2 to 132 months, 24 months [18; 33]; 9 patients were diagnosed with urticarial vasculitis, the duration ranged from 7 to 180 months, 30 [24; 84]. There were 2 patients diagnosed with hypocomplementemic urticarial vasculitis syndrome; the duration of the disease was 24 months. Clinically, chronic spontaneous urticaria was distinguished by a shorter duration of the disease and a shorter duration of existence of individual elements. Standard or increased doses of antihistamines were effective in five patients with chronic spontaneous urticaria. In addition, patients with chronic spontaneous urticaria also had atypical signs of rashes, which indicates a transition group between chronic spontaneous urticaria and urticarial vasculitis. In patients with urticarial vasculitis and hypocomplementemic urticarial vasculitis syndrome, clinical features such as longer duration of blistering, burning and soreness, residual hyperpigmentation, and resistance to antihistamine therapy were more often observed. When conducting a histological examination, the main histological features for urticarial vasculitis were leukocytoclasia, fibrin deposits and damage to the vascular walls with fibrin deposition; fibrinoid necrosis was rarely visualized, which, in combination with the above features, was present in only two patients with hypocomplementemic urticarial vasculitis syndrome.

CONCLUSION: This study presents the results of our own observations, analysis of the clinical and histological characteristics of patients with various diseases (chronic spontaneous urticaria, urticarial vasculitis, hypocomplementemic urticarial vasculitis syndrome). The results obtained may be useful for optimizing the differential diagnosis of diseases accompanied by urticarial rashes.