BASCULE syndrome in a child with prior asymptomatic COVID-19 infection.

BASCULE syndrome, characterized by Bier anemic spots, cyanosis, and an urticaria-like eruption, has been described as a benign vasomotor dermatosis that occurs in the setting of transient tissue hypoxia. It has been postulated that dermal ischemia triggers an exaggerated vasoconstrictive arteriolar reaction, which then causes a paradoxical urticarial rash by an unknown mechanism. In patients with COVID-19, there is evidence of angiocentric inflammation leading to vasoconstriction, endothelial damage, and thrombosis.