Pigmentary lines of the newborn: a case report and review of the literature.

Various diseases of pigmentation in the newborn are known, such as congenital or acquired linear hyperpigmentation. Pigmentary lines of the newborn are counted among the transient benign cutaneous lesions in the newborn and appear to be rather rare. This paper reports on a newborn with pigmentary lines in the creases of the abdomen. The 5-month-old boy is the first case observed so far in the University Hospital of Basel in Switzerland. He was born at term and healthy, without any congenital abnormalities. The horizontally arranged linear hyperpigmentation appeared shortly after birth and faded spontaneously after 5 months. Pigmentary lines of the newborn are rare and the non-hormonal cause may be flexion in utero or other mechanically induced stimulation. So far, only eight similar cases have been reported, which are listed in a table.