Characteristics of erythema migrans in Borrelia afzelii and Borrelia garinii infections.

Erythema migrans is the most common manifestation of stage I Lyme borreliosis. This study investigated the relation between the subspecies of Borrelia burgdorferi involved, the time of development and the appearance of the manifestation. The study comprised 33 cases of erythema migrans yielding B. burgdorferi sensu lato by culture of skin biopsy. The species was determined by polymerase chain reaction analysis of the cultivated spirochaetes. In 22 of the cases, B. afzelii was demonstrated, whereas 11 yielded growth of B. garinii. All 11 erythemas associated with B. garinii were homogeneous, whereas 20 of the 22 associated with B. afzelii were annular. The garinii erythemas developed more rapidly, and were generally larger than the afzelii erythemas. The observations call for comparison with other geographical areas with similar, and with different, borrelial infection spectra.