Lyme Disease Misdiagnosed as CIDP: When Negative Tests Delay Diagnosis
Weakness and paresthesias suggested a neurologic disorder
Lyme tests were negative and the diagnosis was ruled out
Months later, Lyme disease was confirmed—and treatment led to recovery
A woman presented with asthenia, weakness, and diffuse paresthesias. Electromyography revealed mild demyelination, raising concern for a neurologic disorder.
Lyme disease was ruled out based on negative serum and cerebrospinal fluid serologic tests.
When Lyme Disease Mimics CIDP
The patient was diagnosed with chronic inflammatory demyelinating polyneuropathy (CIDP) and treated with intravenous immunoglobulin (IVIG) on eight occasions. She experienced only a partial response, followed by relapse.
CIDP is a neurological disorder involving inflammation of nerve roots and peripheral nerves, leading to destruction of the myelin sheath and resulting in progressive weakness and sensory dysfunction.
Negative Tests Do Not Always Rule Out Lyme Disease
Despite negative initial testing, Lyme disease may still be present. As discussed in our Lyme test accuracy guide, serologic tests can miss infection depending on timing, immune response, or disease stage.
In this case, Lyme disease was diagnosed 10 months after symptom onset when a serum polymerase chain reaction (PCR) test detected Borrelia (100 copies/mL).
Recovery After Correct Diagnosis
The patient was treated with 6 weeks of doxycycline and hydroxychloroquine. She experienced “a dramatic clinical improvement” with complete resolution of neurologic symptoms, according to Perronne.
This outcome highlights the importance of reconsidering Lyme disease in patients with persistent neurologic symptoms—especially when initial diagnoses do not fully explain the clinical course.
Why This Matters
Misdiagnosis can delay effective treatment. Cases like this reflect broader patterns seen in delayed Lyme disease diagnosis, where negative tests or overlapping conditions lead clinicians away from the correct diagnosis.
Lyme disease should not be excluded solely on the basis of negative serologic tests—especially when symptoms remain unexplained or treatment responses are incomplete.
Related Articles:
References:
- Perronne C, Lacout A, Marcy PY, El Hajjam M. Errancy on Lyme Diagnosis. Am J Med. 2017;130(5):e219. View study
- Cameron DJ. Consequences of treatment delay in Lyme disease. J Eval Clin Pract. 2007;13(3):470-472.
- National Center for Advancing Translational Sciences. rarediseases.info.nih.gov
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
I had a positive IGG western blot test in May 2020 after receiving multiple ticks bites in the Dordogne region of France over a period of several years. No rash was ever detected.
Symptoms elevated in the last 3 months seem to be an exact replica of those described in this article, however the doctors in Norway, where my my MRI and lumbar puncture were performed expressed that the mild demyelination that showed was indicative of a “ normal” result for my age (55). Even though borrelia antibodies were found in the spinal fluid it was assessed as being negative for borreliosis. It seems very difficult to confer with a LLMD in Europe and they do not exist in Scandinavia. I am currently still on a two month waiting list with a LLMD in the Netherlands. It would be so helpful to speak with someone who has expertise in this field.
How are you doing now Lisa? Were you able to locate a reputable physician(s) interested in considering your case of CIDP related to Lyme borreliosis? Please be careful regarding so called LLMD’s. They are often self-proclaimed and are prone to self-promotion through dubious methods. Be particularly wary of doctors who demand payment, some in cash, upfront. That’s a clear indicator in the US at least, that the physician probably uses treatment(s) that are considered “alternative” at best and most importantly, have not been subjected to scientific scrutiny. I pray you are doing better.