Importance of anticomplement immunofluorescence antibody titration for diagnosing varicella-zoster virus infection in Bell's palsy.

Anticomplement Immunofluorescence was used for antibody titration against varicella-zoster virus (VZV) in 43 patients with peripheral facial palsy. Nine of 31 patients (29%) with Bell's palsy and eight of 12 patients (75%) with Ramsey-Hunt syndrome had anticomplement immunofluorescence antibody titres of greater than or equal to 1/10. On the other hand, none of 14 patients with herpes simplex virus (HSV) infection and 51 healthy adults showed anticomplement immunofluorescence antibody titres of greater than or equal to 1/10. The anticomplement immunofluorescence antibody titre in two patients with Ramsey-Hunt syndrome increased later and decreased sooner than the indirect immunofluorescence antibody titre, becoming undetectable at 66 and 104 days, respectively, after onset of the disease. There was no cross reaction between anti-VZV and anti-HSV antibodies in the patients who showed a positive antibody rise for VZV. As the acute stage of VZV infection is obscure in the patients with peripheral facial palsy without herpes the screening of anticomplement immunofluorescence antibody to VZV at titres greater than or equal to 1/10 may be useful for the diagnosis of VZV infection in patients with peripheral facial palsy.