The investigators will compare the outcome of three groups of erythema migrans patients treated with doxycycline: a group without any accompanying symptoms, with mild symptoms and with severe symptoms that require lumbar puncture.

Patients with erythema migrans treated with doxycycline for two weeks will be followed-up for one year (at 2 weeks, 2, 6 and 12 months) clinically and also by filling in the questionnaire to assess the presence of certain symptoms. Also the control group of their friends or relatives without a history of Lyme borreliosis will be included. The presence of their (unspecific) symptoms will also be recorded by the questionnaire at the time of enrollment and at 6 and 12 months.

Inclusion Criteria:

• presence of erythema migrans
• >15 years old
• informed consent

Exclusion Criteria:

• pregnancy
• lactation
• multiple erythema migrans
• already treated with antibiotic for this episode of Lyme borreliosis
• allergy to doxycycline
• treatment with drugs with known interactions with doxycycline
• cerebrospinal fluid pleocytosis

Patients with erythema migrans reffered to Lyme Borreliosis outpatient clinic of the University Medical Center Ljubljana, Slovenia, Department of Infectious Diseases.