Covid19 disease is still widely unknown and we are progressively learning its complications and manifestations. Necrotizing vasculitis has been described as a common histopathological finding in SARS-CoV-2 infected patients [4], with typical features. Enteric and bowel involvement, however, is not yet clear: some authors suggest it is present in up to 50% of the cases [5]. Furthermore, SARS- Cov-2 has been detected in samples from faeces suggesting that virus can actively infect and replicate in the GI tract [6] leading to different forms of colitis; a common feature for the other member of coronavirus family. Nowadays, exact mechanism of viral infection causing intestinal symptomatology is not yet understood, Angiotensin-Converting Enzyme 2 (ACE 2) receptor, known as the SARS CoV-2 receptor on human, is expressed not only by lung but also by intestinal epithelium: mouse models shows that ACE2 receptor modifications can be associated with higher rate in colitis, suggesting that receptor modification due to virus infection can increase risk of developing intestinal inflammation and colitis [5]. It is also known that COVID-19 patient, especially with more severe forms of disease, suffered for an acute systemic inflammatory response due to cytokine storms that can develop a multiple organs injury [7], often driven by vasculitis as initial damage. In our case Clostridium Difficile (CD) Pseudomembranous colitis has been the first suspicion: the surgical specimen was suggestive and the patient presented predisposing factors such as in-hospital length of staying, advanced age, illness severity and prolonged antibiotic therapy. Since laboratory tests were always negative and the patient showed improvement without CD specific therapies, we identified the cause of pseudomembranous colitis and perforation in necrotizing vasculitis, closely related to Covid19[6]. Its presence on histopathology on the surgical piece and the presence of viral RNA in the gastric fluid strongly support the hypothesis of an enteric localization of SARS-Cov-2: our laboratory, unfortunately, is not able to detect the viral presence in the stool.
We, here, describe a possible critical complication of the still largely unknown disease related to SARS-CoV-2 infection. Many Covid 19 patients presents GI symptoms together with respiratory ones (2,5). Gastro-enteric involvement may be due to enteric virus replication. Necrotizing vasculitis is a histopathological pattern commonly found in Covid-19 patients in several organs. Clostridium difficile negative pseudomembranous colitis due to a necrotizing vasculitis, in our case, may be a SARS-CoV-2 infection complication too.
This case highlights how our Covid-19 related clinical findings knowledge is still incomplete, and suggests the need to be aware for every symptom to quickly diagnose and prevent possible complications.
Further data are needed to confirm our observations.