A 60-Year-Old Swiss Woman Presenting with Migratory Radicular Pain Diagnosed with Lyme Disease by Western Blot.

BACKGROUND Many diagnostic guidelines have been established to support the diagnosis of Lyme disease, but a recent meta-analysis did not find that 2-tier tests were better than individual tests. Here, we present the case of a patient who was diagnosed by immunoblot only, a second-line test that is usually not performed if the first-line test is negative. CASE REPORT A 60-year-old Swiss woman, without relevant comorbidities, presented to our clinic with 1-week symptoms of migratory radiculitis in the L1, L2, and L5-S1 right dermatomes. Blood analysis and lumbar and brain MRI did not show any significant abnormalities. However, unexpected results were obtained after testing Lyme serologies. They were performed first with LIAISON® test (Diasorin, Italy) then with Borrelia VIRAstripe® immunoblot (Viramed, Germany) and a positive IgM result was only obtained with the latter. Consequently, doxycycline 100 mg 2×/day was initiated and the symptoms completely resolved after 6 weeks of treatment. Ever since, and more than 1 year after the initial presentation, the patient remains symptom-free. CONCLUSIONS As shown, it was possible to diagnose this patient and treat her successfully by testing all the available serologies. Furthermore, we were surprised to find out after a review of the literature that the IgM sensitivity in neuroborreliosis with the LIAISON® test is only 43.9-46% versus 90-100% with VIRAstripe®. Hence, clinicians need to understand the pitfalls of these tests before excluding Lyme disease.