Description
Erythema migrans is a red papule that slowly expands and typically reaches a diameter of at least 5 cm. The enlarging papule often clears centrally to create a annular rash at the site of the tick bite. It is the first sign of Lyme disease in about 90% of cases. [CCDM, p. 315] A similar rash has been described in cases of Southern tick-associated rash illness (STARI). [CDC] Also called "erythema chronicum migrans";