Erythema migrans (EM) or “bull’s-eye” rash at bite site.
Less than 50% of people, bitten by a deer tick, who contract Lyme disease, develop an erythema migrans (EM) rash. 1 About 9% get the typical bullseye rash, which is one subset of the EM rash. Some people do not get any rash at all.
Image typical EM Rash. Image courtesy of Ed Masters
1 R. Smith et al Annals of Internal Medicine 2002;421:421-428, 477-479;
A. Pachner Reviews of Infectious Diseases-Vol. II, supplement 6 – September-October 1989 Neurologic Manifestations of Lyme Disease, the new “Great Imitator;
B.J.M. Johnson, Ph.D., Chief, Public Health, NPS Ticks and Disease