Quincke’s sign, also known as Quincke’s pulse, represents the visualization of capillary pulsations upon light compression applied to the tip of the fingernail bed. It is an eponym associated with chronic severe aortic insufficiency. A patient exhibiting this sign will have alternating reddening and blanching of the nailbed with each pulsation. This sign can be further enhanced with the use of illumination.
Quincke’s sign was named after Dr. Heinrich Quincke, who first coined the term in 1868. He was a German physician who contributed numerous medical discoveries, including identifying angioedema, the technique of the lumbar puncture, and the description of what is now known as idiopathic intracranial hypertension.