Immunoglobulin M immunoblot for diagnosis of Borrelia burgdorferi infection in patients with acute facial palsy

We used immunoblotting to improve the specificity of the serologic diagnosis of Lyme borreliosis in cases of acute facial palsy. Twelve of 15 patients (80%) with suspected Lyme borreliosis, versus 0 of 10 controls, were positive by immunoglobulin M immunoblotting of acute-phase sera and 3 were negative, including 2 with borderline enzyme immunoassay results. Immunoglobulin M immunoblotting is a useful test to confirm Borrelia burgdorferi infection in patients with acute facial palsy and a positive enzyme immunoassay result.