Labor and Delivery Practice Test

Harlequin color change is a benign vasomotor disturbance of the newborn’s skin vessels that creates a sharp, midline boundary between two halves of the body. One side becomes red due to relative vasodilation, while the opposite side becomes pale from vasoconstriction. This gives the characteristic half-and-half appearance.

The phenomenon stems from immature autonomic control of cutaneous blood flow. It can be triggered by changes in position or temperature and usually resolves on its own within minutes to hours without any treatment. It’s most commonly observed in newborns during the first day or so of life.

It differs from acrocyanosis, which is a symmetrical blue discoloration of the hands and feet due to peripheral slow perfusion and is not a midline half-and-half pattern. Icterus neonatorum refers to jaundice from bilirubin buildup, presenting as yellowing rather than a sharp red/pale split. Vernix caseosa is the white, cheesy coating on the skin, not a color change.