Lyme arthritis is rare in Eastern Denmark.

Area of Science:

• Infectious Diseases
• Rheumatology
• Clinical Microbiology

Background:

• Lyme borreliosis is a multi-organ disease that can manifest as arthritis, primarily affecting large joints.
• Currently, no established guidelines exist for diagnosing Lyme arthritis (LA).
• The incidence of LA in Denmark is unknown but presumed to be low.

Purpose of the Study:

• To quantify Borrelia burgdorferi serological tests requested in Danish primary and secondary care.
• To determine the frequency of Lyme arthritis diagnoses.
• To assess the need for diagnostic guidelines for LA.

Main Methods:

• A register-based study analyzing Borrelia burgdorferi serological tests from Hvidovre and Herlev Hospitals over two years.
• Categorization of test requests into primary and secondary care.
• A medical record review of newly referred rheumatology patients to develop and apply a diagnostic model for LA.

Main Results:

• Primary care requested the majority of Borrelia burgdorferi tests.
• Of 118 newly referred rheumatology patients tested, three had possible LA and one had likely LA, with no final LA diagnoses.
• Rheumatologists did not commonly overdiagnose Lyme arthritis.

Conclusions:

• A significant number of Borrelia burgdorferi tests are performed, particularly in primary care.
• There is a clear need for standardized diagnostic guidelines for Lyme arthritis in both primary and secondary care settings.
• The study highlights potential challenges in diagnosing Lyme arthritis accurately.