TY - CHAP M1 - Book, Section TI - Erythema Migrans A1 - Hardin, J. Matthew A2 - Knoop, Kevin J. A2 - Stack, Lawrence B. A2 - Storrow, Alan B. A2 - Thurman, R. Jason PY - 2021 T2 - The Atlas of Emergency Medicine, 5e AB - Borrelia burgdorferi is the tick-borne spirochete responsible for Lyme disease, and erythema migrans is the 1st cutaneous sign. Erythema migrans typically presents 1 to 2 weeks after the bite. The initial prodromal symptoms of fever, myalgias, arthralgias, and headache are followed by a macule or papule progressing to a plaque at the bite site. This plaque expands (usually to 5 cm or larger) its red, raised border as it clears centrally, leading to an annular appearance (“bull’s eye”). The plaque may burn and is rarely pruritic. Less frequently, secondary erythema migrans–like lesions can appear due to multiple bites or spirochetemia. Erythema migrans is seen in 60% to 90% of patients and represents the early localized stage. SN - PB - McGraw-Hill CY - New York, NY Y2 - 2024/03/28 UR - accessemergencymedicine.mhmedical.com/content.aspx?aid=1181043836 ER -