Keratoderma with pseudo-Quincke's pulse

The physical examination sign known as Quincke's capillary pulse is elicited by pressing lightly on the distal edge of a fingernail. When the vasculature of the nailbed is partly blanched, Quincke's pulse appears as alternating flashes of red and white that reveal arterial pulsations. This sign is seen in many normal persons, but it is most prominent in individuals with widened pulse pressures, such as aortic insufficiency. This case report describes a patient with keratoderma and sclerodactyly whose fingernails exhibited rapid color changes, mimicking Quincke's pulse. The visible pulsations were due to sclerodactylous compression of the nailbeds, and not to any primary hemodynamic process.