Purpuric Skin Rash in a Patient Undergoing Pfizer-BioNTech COVID-19 Vaccination: Histological Evaluation and Perspectives

The COVID-19 pandemic has affected the entire planet, and within about a year and a half, has led to 174,502,686 confirmed cases of COVID-19 worldwide, with 3,770,361 deaths. Although it is now clear that SARS-CoV-2 can affect various different organs, including the lungs, brain, skin, vessels, placenta and others, less is yet known about adverse reactions from vaccines, although more and more reports are starting to emerge. Among the adverse events, we focused particularly on skin rashes. In this short report, we describe the case of a patient vaccinated with Comirnaty, who developed a purpuric rash resistant to oral steroid therapy after 2 weeks. To date, this is one of the very few cases in which skin biopsy was performed to better characterize the histopathological picture of this rash. Finally, we conduct a literature review of the cases of rashes from SARS-CoV-2 vaccines described in the literature, with the aim of laying foundations for future, larger case studies.