Lyme disease, a condition caused by the bacterium Borrelia burgdorferi, is transmitted to humans through the bite of infected ticks. This illness can manifest in various ways, affecting multiple body systems. Lyme disease can indeed cause arthritis, a condition specifically known as Lyme arthritis.
Lyme Arthritis Connection
Lyme arthritis develops when Borrelia burgdorferi bacteria, introduced through a tick bite, disseminate throughout the body and invade joint tissues. The presence of these bacteria in the synovial fluid and surrounding joint structures triggers an immune response. This response leads to inflammation within the joints.
The inflammation is largely an immune-mediated process, where the body’s immune system, while fighting the infection, inadvertently contributes to arthritic symptoms. This direct link makes Lyme arthritis a recognized manifestation of Lyme disease, especially in later stages.
Characteristics of Lyme Arthritis
Lyme arthritis typically presents as intermittent or persistent joint swelling and pain. The condition often affects one or a few large joints, with the knee being involved in up to 90% of cases. Other large joints, such as the shoulder, ankle, elbow, hip, and wrist, can also be affected.
Joint swelling can be noticeable, sometimes disproportionate to the pain. The affected joints may feel warm to the touch, and movement can be limited. Episodes of joint inflammation can appear weeks to months after the initial infection, and they may subside on their own, only to recur later. Unlike some other forms of arthritis, Lyme arthritis is rarely a symmetric condition involving small joints.
Diagnosis of Lyme Arthritis
Diagnosing Lyme arthritis involves a combination of clinical assessment and laboratory testing. A healthcare provider will consider the patient’s history, including potential exposure to ticks, and conduct a physical examination to evaluate joint symptoms like swelling, warmth, and pain.
Laboratory testing for Lyme disease primarily relies on serologic assays designed to detect antibodies to Borrelia burgdorferi. The most common approach is a two-step testing process. The first step typically uses an enzyme-linked immunosorbent assay (ELISA) to screen for antibodies. If the ELISA result is positive or indeterminate, a second, more specific test, such as a Western blot, is performed to confirm the presence of antibodies. A positive result requires both steps to be reactive.
Treatment Approaches for Lyme Arthritis
The primary treatment for Lyme arthritis is antibiotic therapy, which targets the underlying bacterial infection. Oral antibiotics such as doxycycline, amoxicillin, or cefuroxime axetil are commonly prescribed. For an initial episode of Lyme arthritis, a 4-week course of oral antibiotics is typically recommended.
Antibiotics eliminate the Borrelia burgdorferi bacteria, addressing the root cause of joint inflammation. Supportive care for joint pain and inflammation may also be used.