The authors present the case of a patient 75-year-old woman with ischemic optic neuropathy (ION) caused by varicella zoster virus (VZV) without zoster rash. They demonstrate that early VZV infection of the temporal artery adventitia occurs in VZV vasculopathy, suggesting that extracranial arteries become infected transaxonally after VZV reactivates from ganglia. They conclude that it is important to distinguish between VZV vasculopathy-associated ION and giant cell arteritis (GCA)-associated (arteritic) ION in patients with headache, vision loss and elevated erythrocyte sedimentation (ESR) rate, since treatment with high-dose steroids would be contraindicated or aggravate disease in VZV vasculopathy.
Before diagnosis, the patient was treated with steroids for presumed GCA and noted transient improvement of pain and vision, perhaps due to decreased inflammation. However, only two weeks later, she became blind in the affected eye, most likely because she did not receive antiviral treatment for VZV infection that might have been potentiated by steroid treatment.
The patient was not clinically symptomatic for GCA. VZV antigen was identified in the adventitia of the temporal artery, and the biopsy specimen was pathologically negative for GCA. Anti-VZV IgG antibody was detected in the cerebrospinal fluid (CSF).
VZV vasculopathy can be distinguished from GCA histologically since VZV primarily affects the adventitial layer of the artery and GCA primarily affects the media layer of the artery. In addition, VZV antigen is not found in temporal arteries of pathologically verified cases of GCA.
The authors say this case expands the spectrum of disease produced by VZV without rash to ION, reveals ipsilateral GCA-negative temporal artery VZV infection useful in diagnosis, and confirms early VZV infection of adventitia in VZV vasculopathy, providing additional evidence that extracranial arteries become infected transaxonally after VZV reactivates from ganglia.
Because both GCA and VZV vasculopathy without rash present with headache, vision loss and elevated ESR, it is important to consider and diagnose VZV vasculopathy since long-term steroid treatment for presumed GCA may aggravate disease. Virologic confirmation requires either detection of VZV DNA or anti-VZV antibody in CSF or detection of VZV antigen in temporal artery biopsy. Lack of detection of productive VZV infection in patients with GCA is not surprising since both necrosis and inflammation in media are characteristically seen in acute GCA, while only inflammation is seen in adventitia of early VZV vasculopathy.
The authors say that because VZV can be found in GCA-negative temporal artery in ION, even without rash, it would be prudent to examine GCA-negative temporal artery biopsies for VZV antigen, particularly since VZV infections respond to antiviral therapy.