erythema anulare centrifugum

er·y·the·ma an·u·lare cen·tri·fu·gum

(er'i-thē'mă an-yū-lā'rē sen-trif'yū-gŭm)
A chronic, recurring erythematous eruption consisting of small and large anular lesions, with a scant marginal scale, usually of unknown cause.