Introduction: Nicolau syndrome (NS), also known as livedo-like dermatitis or embolia cutis medicamentosa, is a very rare complication of intramuscular and intraarticular injection of various drugs.
Case report: We herein report a case of NS developing approximately 2 h after the intramuscular administration of vitamin K1 in an extremely low birth weight premature newborn. To our knowledge, this patient is the youngest case suffering from such a livedoid skin necrosis and the first case of neonatal NS developing due to intramuscular administration of vitamin K1.