Vasculitis syndromes: the pathogenic roles of COVID-19 and related vaccinations.

Infection by SARS-CoV-2 has contributed to more than four million deaths worldwide. Based on clinical observations, it has been revealed that the virus can easily disturb the function of various organs in the body. Besides its main damage to the respiratory system, the extra-pulmonary manifestations are deemed to be common in affected patients even after COVID-19 vaccination. COVID-19 has been accompanied by various types of skin manifestations, including varicella-like exanthemas, dengue-like petechial rashes, or urticarial eruptions. However, not only have viral rashes been related to COVID-19, but also other types of skin symptoms that are reminiscent of a vascular disease, such as acro-ischaemic lesions. This literature review aims to provide information on various forms of COVID-19-induced vasculitis and vasculitis following vaccination. It has been hypothesized that various forms of vasculitis can be considered as pathological consequences following SARS-CoV-2 infection. Numerous suggested mechanisms are involved in vasculitis, including the deregulation of the immune system, increased activation of mastocyte, augmented production of proinflammatory cytokines, which in turn lead to indirect endothelial damage, complement system activation, recruitment of neutrophils, and deposition of immune complexes. Based on previous studies, the mRNA-based COVID-19 vaccine is much more implicated in relation to vasculitis. SARS-CoV-2 and COVID-19 vaccination lead to the onset and relapse of different types of vasculitis that should be clinically evaluated by exact monitoring.