How many Lyme disease patients get erythema migrans?
A number of published studies have shown that the proportion of diagnosed Lyme disease patients who present the characteristic rash erythema migrans (EM) is within the range 85 to 95%. The journal Clinical Infectious Diseases (Krause 2002) examines patients suspected of early Lyme disease, babesiosis, and/or anaplasmosis. Among confirmed Lyme disease patients who are not coinfected with other tick-borne diseases, 90% exhibit an EM. Another study published in the New England Journal of Medicine (Gerber 1996) finds that among children (mean age: 7 years) diagnosed with Lyme disease, 89% exhibit an EM.
