[Diagnosis and treatment of Lyme arthritis. Recommendations of the Pharmacotherapy Commission of the Deutsche Gesellschaft für Rheumatologie (German Society for Rheumatology)].

These guidelines summarize the current evidence for diagnosis and treatment of Lyme arthritis and the most frequent skin manifestations of Borrelia burgdorferi infections. Lyme arthritis is a monoarticular or oligoarticular form of arthritis that typically involves the knee. A positive enzyme-linked immunosorbent assay (ELISA) for IgG antibodies should be followed by an IgG immunoblot. A positive PCR test from synovial fluid adds increased diagnostic certainty. Serum positivity for antibodies to Borrelia burgdorferi without typical symptoms does not justify antibiotic treatment. Oral antibiotic treatment for erythema migrans is recommended using doxycycline, 200 mg once per day for 10-21 days, alternative choices are amoxicillin, cefuroxime and azithromycin. For children below 8 years of age, amoxicillin is recommended.Lyme arthritis can usually be successfully treated with orally administered antimicrobial agents. Doxycycline, 1 × 200 or 2 × 100 mg for 30 days is the antibiotic agent of choice. Amoxicillin (3 × 500-1000 mg) can be alternatively chosen. Patients who have persistent or recurrent joint swelling after a recommended course of oral antibiotic therapy should be treated intravenously. In this situation, ceftriaxone at 2 g per day for 14-21 days is recommended. There is no evidence to recommend long-term and combined treatments.