Clinical outcome of erythema migrans after treatment with phenoxymethyl penicillin.

In a 5 y retrospective follow-up study in southern Sweden of 708 adult individuals with erythema migrans as the single manifestation of Lyme borreliosis, the clinical outcome and the antibiotic treatment were studied. 80% were treated with phenoxymethyl penicillin, 15% with doxycycline and 5% with other antibiotics. Phenoxymethyl penicillin and doxycycline were extremely effective: 98 and 94% of the individuals reported complete recovery without complications. Few individuals reported the development of new symptoms following treatment and none developed any late manifestation of Lyme borreliosis during the observation period. Thus, in the area studied the treatment of the early localized manifestation of Lyme borreliosis (erythema migrans) with antibiotics was extremely successful. The current Swedish recommendation to use phenoxymethyl penicillin, when no sign of disseminated infection or coinfection with other tick-borne pathogens is present, seems excellent.