Background: Comparison of clinical efficacy and adverse effects of treatment with azithromycin and amoxicillin in children with solitary erythema migrans (EM).
Methods: Consecutive patients younger than 15 years with untreated solitary EM referred to our institution 2002-2003 were included in this unblinded prospective clinical study in which patients were alternatively treated with either azithromycin for 5 days or amoxicillin for 14 days. The efficacy of treatment of acute disease, development of minor and major manifestations of Lyme borreliosis and adverse effects of treatment were surveyed by follow-up visits during the first year after inclusion.
Results: Eighty-four patients received azithromycin and 84 amoxicillin. Pretreatment characteristics in the 2 groups were comparable with the exception that patients in azithromycin group more often reported a tick bite at the site of later EM (69% versus 52%; P = 0.0400), had more often EM on the trunk (50% versus 26%; P = 0.0025) and reported longer duration of symptoms (median 3 versus 2 days; P = 0.0283). The posttreatment period revealed no significant differences between azithromycin and amoxicillin groups including the duration of EM (median 3 days; P = 0.8984) and the appearance of minor (12% versus 21%; P = 0.2146) and major manifestations (2.6% in each group) of Lyme borreliosis. Adverse effects of treatment were observed in 21% of patients treated with azithromycin and in 16% treated with amoxicillin, and the appearance of Jarisch-Herxheimer reaction was recorded in 7% and 15%, respectively (P = 0.1438).
Conclusions: Comparison of azithromycin and amoxicillin for the treatment of children with solitary EM revealed comparable efficacy and adverse effects of treatment.