 Neonatal jaundice spreads in a cephalo-caudal pattern, affecting the face and neck before spreading down to the trunk and lower extremities in more severe cases.Other symptoms may include drowsiness, poor feeding, and in severe cases, unconjugated bilirubin can cross the blood-brain barrier and cause permanent neurological damage (kernicterus).The most common cause of jaundice in infants is normal physiologic jaundice.