Cutaneous Endothelial Dysfunction and Complement Deposition in COVID-19

Bullous dermatosis on the hands following SARS‐CoV‐2 infection

“…Vascular lesions encompassing chilblain‐like lesions and acral necrosis have been largely associated with COVID‐19 1 . The reported occurrence of vascular lesions supports the hypothesis that endothelial dysfunction plays a key role in organ injury 2 . Many hypotheses have been advanced to explain the onset of endothelial damage in COVID‐19 patients: It has been considered as an immunological reaction to viral antigens deposition; also, immune activation, especially high level of IL‐6, and the stimulation of the coagulation system due to viral load have been proposed as possible triggers 3 …”

“…The novel coronavirus SARS‐CoV‐2, which causes Coronavirus disease 2019 (COVID‐19), can lead to heterogeneous symptoms which range from interstitial pneumonia to generalized disturbances characterized by severe immune responses and aberrant inflammation, which may be associated to various dermatologic manifestations 1,2 …”

Chilblains-Like Lesions in Pediatric Patients: A Review of Their Epidemiology, Etiology, Outcomes, and Treatment

“…The gross descriptions of biopsies noted edema in 33 cases ( 6 , 10 – 12 , 18 , 29 , 31 , 33 , 35 , 41 ). Additional findings included vacuolar changes in 36 cases, spongiosis changes in 27 cases, mucin deposits in 22 cases, red cell extravasation in 18 cases, fibrin deposition in eight cases, purpura in seven cases, vascular ectasia in three cases, dilated blood vessels in two cases, necrosis in two cases, and degeneration of endothelial cells in one case ( 6 , 10 , 11 , 18 – 20 , 22 , 26 , 35 , 41 , 45 , 51 , 52 ). Eight biopsies demonstrated swollen endothelial cells, and an unspecified number of samples had tubule-reticular inclusions within the endothelial cells ( 10 , 18 , 19 , 41 ).…”

“…Lymphocytes were commonly reported as the dominant tissue infiltrate and were present in 129 instances; CD3+ T lymphocytes were reported in 14 samples ( 6 , 10 – 12 , 17 – 20 , 22 , 29 , 31 , 33 , 35 , 41 , 45 , 51 , 52 ). The infiltrate was perivascular in 75 cases, perieccrine in 42 cases, and periadenexal in 3 cases ( 6 , 10 – 12 , 18 – 20 , 22 , 31 , 33 , 35 , 41 , 45 , 51 , 52 ). CD20+ B cells were also reported in 12 instances ( 18 ).…”

Vascular Endothelial Glycocalyx Damage and Potential Targeted Therapy in COVID-19

“…Early in COVID-19, SARS-CoV-2 enters pulmonary epithelial cells via surface angiotensin-converting enzyme 2 (ACE2) receptors, resulting in viral pneumonia, followed by a systemic inflammatory phase [ 1 , 2 , 3 ]. Typical clinical symptoms of SARS-CoV-2 infection includes acute respiratory distress syndrome (ARDS), systemic inflammatory response syndrome (SIRS), multiple organ failure (MOF), and disseminated intravascular coagulation (DIC) [ 2 , 4 , 5 ]. Some other clinical events usually observed in COVID-19 patients, including high blood pressure, thrombosis kidney disease, pulmonary embolism, Kawasaki disease, cerebrovascular and neurologic disorders, mesenteric ischemia, and cutaneous vasculitis, all indicating that the virus impairs vascular endothelial function [ 6 , 7 ].…”