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 complaints that newly developed or intensified since the onset of erythema migrans or since the date of enrollment for controls were referred to as "new or increased symptoms"(NOIS).

Inclusion Criteria:

• typical solitary erythema migrans as defined by the United States Centers for Disease Control and Prevention. In addition, patients with skin lesion <5 cm in diameter were also included if they recalled a recent tick bite at the site of the skin lesion, had a symptom-free interval between the bite and the onset of the lesion, and reported an expanding skin lesion prior to diagnosis.

Exclusion Criteria:

• Lyme disease previously
• pregnancy or lactation
• immunocompromised
• serious adverse reaction to a beta-lactam or tetracycline drug in the past
• received an antibiotic with known anti-borrelial activity within 10 days
• multiple erythema migrans lesions
• presence of an extracutaneous manifestation of Lyme disease