In a study published in the American Journal of Pathology, researchers revealed the use of a minimally invasive test to find blood clots in small blood vessels in the skin of patients who had severe COVID-19. These clots appeared normal and were not present in the skin of patients who had other types of severe infectious lung diseases or in people who only had mild or moderate COVID-19.

A skin biopsy, according to the researchers, can aid in determining the extent of COVID-19-related tissue damage as well as helping in separating this blood vessel disease from other severe respiratory infections. The study also included biopsy samples from 9 hospitalized patients who had severe or critical respiratory or kidney diseases and passed away prior to the COVID-19 era. Also, MxA an antiviral protein which can stop SARS-CoV-2 growth was detected in all the 6 mild to moderate COVID-19 patients. 

Microthrombi or small blood clots were seen in 13 of the 15 patients with severe or critical COVID-19 while no microthrombi were found in the biopsies of patients with mild to moderate COVID-19 or the pre-COVID-19 era patients with severe respiratory sickness or kidney disorders. The scientists stated that these microvascular changes may be a unique characteristic of COVID-19 respiratory disorder compared to other acute respiratory diseases. (Hindustan Times, Jul 15, 2022)