erythema migrans a bullseye rash at the portal of entry is associated with

Erythema migrans, a bull’s-eye rash at the portal of entry, is associated with Lyme disease. Lyme disease is a bacterial infection transmitted by ticks. The bull’s-eye rash is the most characteristic symptom of Lyme disease, although not everyone with Lyme disease will develop it.

The rash typically appears 7-14 days after a tick bite and expands slowly over a few days or weeks. It can reach up to 12 inches in diameter. The center of the rash may clear, creating a bull’s-eye appearance. The rash is usually painless, but it may be warm to the touch.