Lyme disease causes a rash.
Erythema chronicum migrans ( New Latin , literally , `` chronic migrating redness '' ) refers to the rash often ( though not always ) seen in the early stage of Lyme disease . Lyme disease . The most common sign of infection is an expanding area of redness on the skin , known as erythema migrans , that begins at the site of a tick bite about a week after it has occurred .