Beau's Lines and COVID-19; A Systematic Review on Their Association.

BACKGROUND: Beau's lines are transverse grooves in the nail plate that result from transient interruption of the growth of the proximal nail matrix after severe disease. The aim of this study is to systematically report all evidence on the association of Beau's lines with COVID-19 infection or vaccination against COVID-19.

METHODS: PubMed and Scopus databases were searched up to January 2024 for articles reporting Beau's lines associated with COVID-19 infection or vaccination for COVID-19.

PROSPERO ID: CRD42024496830.

RESULTS: PubMed search identified 299 records while Scopus search identified 18 records. After screening the bibliography, nine studies including 35 cases were included in our systematic review. The studies were reported from different areas around the world. Included studies documented Beau's lines following COVID-19 vaccination (two studies) or after COVID-19 infection (seven studies). High variability was recorded in onset and resolution times among included cases, averaging 3 months and 6 months after COVID-19 infection, respectively. In the two studies reporting Beau's lines after vaccination, onset was at 7 days and 6 weeks and resolution occurred after 8 and 17 weeks, respectively.

CONCLUSIONS: To the best of our knowledge, this is the first systematic review reporting the association of Beau's lines with COVID-19 infection and vaccination. Severe immune response can result in the formation of these nail disorders. Of importance, Beau's lines represent a potential indicator of prior severe COVID-19 infection or vaccination for COVID-19, as well as a sign of long COVID-19 syndrome.