Could a cryoprotein explain ‘COVID toe’?

Patients with ‘COVID toe’ may have an abnormal cryoprotein in their blood, a study suggests.
The research shows almost two thirds of 54 patients who presented at a hospital in northern Spain with chilblains at the height of the pandemic tested positive for cryofibrinogen.
The abnormal protein signals cryofibrinogenaemia — a rare disorder that can be primary or secondary to another disorder including infections, collagen diseases, vasculitis and malignancy.
The study was carried out at a tertiary hospital in Santander between April and May 2020.