This is an engorged deer tick (Ixodes dammini) embedded in the skin of a human host. In the United States, these ticks are the primary source of Lyme disease. (Image courtesy of the Centers for Disease Control and Prevention and M. Fergione.)
Review Date 6/30/2019
Updated by: Jacob L. Heller, MD, MHA, Emergency Medicine, Emeritus, Virginia Mason Medical Center, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.