Background: Controversy exists over the significance and even the existence of post-Lyme disease symptoms because of the high rate of similar background symptoms in the general population.
Methods: A European, prospective clinical trial in which doxycycline and cefuroxime axetil were compared in the treatment of adult patients with erythema migrans included a control group to address this question. Evaluations of patients were conducted at baseline, 14 days, and 2, 6, and 12 months after enrollment. Control subjects were evaluated at baseline and at 6 and 12 months. Subjective symptoms that newly developed or intensified since the onset of erythema migrans or the date of enrollment for controls were referred to as "new or increased symptoms."
Results: Doxycycline and cefuroxime axetil had comparable efficacy. At both 6 and 12 months, the frequency of new or increased symptoms in patients with erythema migrans did not exceed the frequency of such symptoms in a control group of individuals of similar gender and age without a clinical history of Lyme disease. At 12 months after enrollment, only 5 (2.2%) of 230 evaluable patients reported new or increased symptoms, and in none of the patients were these symptoms of sufficient severity to be functionally disabling.
Conclusion: No significant differences were identified between doxycycline and cefuroxime axetil in the treatment of European patients with erythema migrans. The frequency of nonspecific symptoms in patients did not exceed that of a control group at > or =6 months after enrollment. We advocate inclusion of appropriate non-Lyme disease control groups in future studies in which nonspecific subjective symptoms are assessed after antibiotic therapy.
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