Understanding Lab Tests for False Positive Lyme Disease
Written by Private MD Labs Medical Writing Team • Last Updated: September 8, 2025
A false positive Lyme disease result occurs when initial screening tests suggest Lyme disease infection, but the patient doesn't actually have the condition. This can happen because other infections or autoimmune conditions can produce antibodies that cross-react with Lyme disease screening tests, leading to misleading results.
Recommended Test
Lyme Disease Antibody with Reflex to Antibodies IGG & IGM Blot
This comprehensive test includes both initial screening and automatic reflex to confirmatory Western blot testing when the screen is positive. The Western blot analysis helps distinguish true Lyme disease infection from false positive results caused by cross-reactive antibodies from other conditions like syphilis, anaplasmosis, or autoimmune diseases.
2907 reviews
Why False Positives Occur in Lyme Disease Testing
Lyme disease testing relies on detecting antibodies the immune system produces in response to the Borrelia bacteria. However, conditions such as syphilis, anaplasmosis, and certain autoimmune diseases can trigger the production of similar antibodies, causing initial screening tests to appear positive even without a true Lyme infection.
Confirmatory Testing to Rule Out False Positives
When a Lyme disease screening test is positive, confirmatory testing with more specific methods is essential to distinguish between a true infection and a false positive result. This two-tiered approach helps ensure accurate diagnosis and prevents unnecessary treatment.
Understanding Your Results
If your initial Lyme screening is positive but confirmatory testing is negative, this likely indicates a false positive result. Your healthcare provider will consider your clinical symptoms, exposure history, and other factors to determine if additional testing for other conditions is needed.
Important Considerations
The information here is for educational purposes only and is not a substitute for professional medical advice. Always consult with a healthcare provider for proper interpretation of test results and appropriate follow-up care.
