Incidence and antibiotic treatment of erythema migrans in Norway 2005-2009.

The first stage of Lyme borreliosis (LB) is mainly the typical skin lesion, erythema migrans (EM), which is estimated to comprise 80-90% of all LB cases. However, the reporting of, and the actual incidence of LB varies throughout Europe. Studies from Sweden and Holland have found EM incidences varying from 53 to 464 EM/100,000 inhabitants/year.