For more than 100 years, the connection between viral infections and the occurrence and exacerbation of urticaria has been known. As a result of the COVID-19 pandemic, our knowledge of the role of viral infection in acute and chronic urticaria has expanded, but the pathogenesis and cause-and-effect relationships between urticaria and viral infections remain not fully understood. Viral infections, including COVID-19, can provoke the onset of acute and exacerbation of chronic urticaria. This article presents two clinical cases of patients with chronic spontaneous urticaria, in whom an exacerbation of the disease developed against the background of COVID-19 or after an infection. The authors demonstrated variants of the course of the disease and features of the response to biological therapy with omalizumab. Possible predictors of fast and slow response to targeted therapy were analyzed, and the influence of concomitant diseases on the course of chronic urticaria was shown. Today, questions about the need to develop reliable clinically significant biomarkers of response to therapy in patients with chronic spontaneous urticaria continue to be relevant. Issues of cause-and-effect relationships and pathogenetic aspects of the influence of viral infections on the course of urticaria require further research.

Keywords: COVID-19 viral infection, chronic urticaria, omalizumab, biomarkers