A case of glossopharyngeal zoster diagnosed by detecting viral specific antigen in the pharyngeal mucous membrane

Glossopharyngeal nerve paralysis caused by varicella zoster virus reactivation is rare. We present a case of glossopharyngeal zoster confirmed by direct immunofluorescence staining for virus antigens. A 35-year-old man presented with right-sided, severe swallowing pain and dysgeusia. Physical examination showed a loss of ipsilateral gag reflex. White spots on the posterior wall of the right pyriform sinus were seen by laryngofibroscopy, and a loss of taste on the right posterior part of the tongue was confirmed by gustometry using the filter paper disc method. The varicella zoster virus antigen was revealed by direct immunofluorescence staining by fluorescein isothiocyanate labelled mouse monoclonal antibody specific for varicella zoster virus glycoprotein, using samples obtained from the mucosal lesion by abrasion with a cotton swab. The patient was treated by intravenous administration of acyclovir. His throat pain and dysgeusia completely resolved. We discuss the advantages of direct immunofluorescence staining for varicella zoster virus antigen for the diagnosis of glossopharyngeal zoster.