Pseudo-blue lunula and beyond: a normal variant

A 12-hour-old newborn was noted by his parents and primary care team to have distinctive blue nail color changes. The blue color extended from the proximal nail bed to the mid-nail bed region. This did not resolve over the next 2 days, and dermatology was consulted. The child was born full term, and he and his mother had no medical history. He had an Apgar score of 9, and regular pulse oximeter showed > 97% saturation. No signs of cyanosis were noted on full skin and mucosa examination. Complete blood cell count and basic metabolic panel results were unremarkable. The blue discoloration (Figure) was not blanchable and did not resolve with warming of the hands. Physical examination was otherwise unremarkable and no murmur was appreciated. Due to the lack of physical or laboratory alterations, observation was recommended as the best approach. On discharge, the blue discoloration continued and was still noted by the pediatrician on day 7. The parents eventually noted clearance at 2 weeks.