Erythema chronicum migrans
Erythema chronicum migrans is caused by an infection with Borrelia secondary to the bite of the Ixodes tick.
It is an expanding ring of erythema with central clearing.
It is very similar to erythema annulare centrifugum, except that the advancing edge is frequently broader, up to a centimeter of raised erythema.
It is associated with an arthritis known as Lyme arthritis.
- The treatment of choice is the use of penicillin or another antibiotic to which Borrelia is sensitive. Such treatment should be continued for 2-4 weeks.