Recurrent Lyme Disease Rash in Treated Patients Usually Due to Reinfection, Not Relapse

Repeat bouts of erythema migrans after treatment of Lyme disease are most likely reinfections, as opposed to relapses of incompletely treated infections, according to a study in the New England Journal of Medicine.

Researchers in New York analyzed 17 patients who had 22 pairs of consecutive episodes of erythema migrans caused by Borrelia burgdorferi. All episodes were treated with standard antibiotic therapy.

None of the paired consecutive episodes had the same ospC genotype, leading the researchers to conclude that patients had been reinfected with a different strain. In addition, all the recurrent infections occurred 1 year or longer after the initial infection, lending support to reinfection.

An editorialist concludes: "Although B. burgdorferi infection may persist for years in untreated patients, the weight of evidence is strongly against persistent infection as the explanation for persistent symptoms in antibiotic-treated patients with Lyme disease."