Publication date: Feb 15, 2025

It is understood that microvascular dysfunction plays a key role in the pathogenesis of SARS-CoV-2 coronavirus disease (COVID-19). The aim of this study was to evaluate the usefulness of an automated, quantitative nailfold capillaroscopy system in identifying microvascular changes in those confirmed with or having had COVID-19. Ninety-seven participants were enrolled into this study and grouped as follows: 52 participants with acute COVID-19 (further grouped by disease severity) and 45 participants with convalescent COVID-19 (further grouped into long COVID i. e. symptoms beyond 12 weeks, and fully recovered). Nailfold capillaroscopy images were obtained from the bilateral ring fingers using a Dino-Lite CapillaryScope 200 Pro, a small USB handheld microscope. Images were assessed quantitatively using bespoke automated measurement software and the number of haemorrhages noted for each participant. Capillaries were predominantly ‘normal’ in appearance with narrow capillary loops and evenly distributed, but with an increased number of haemorrhages (40 % in the convalescent group and 17 % in the acute group, p = 0. 007). There was no statistically significant difference in the mean width of capillaries (20. 9-21. 8 μm) or vessel density (9. 6-9. 9 caps/mm; acute and convalescent group, respectively). This study has demonstrated the feasibility of nailfold capillaroscopy at the critical care bedside. Capillary structure appeared normal across all groups of individuals affected by COVID-19. Although the small differences in the microvasculature in recovered patients compared to in acutely unwell patients may suggest delayed structural change due to COVID-19, these differences are unlikely to be clinically relevant. Longitudinal studies would be required to explore this in more detail.

Original Article