LAUSR

Herpes zoster (HZ) results from the reactivation of latent varicella-zoster virus in the dorsal root ganglion neurons. The most common complication of HZ is post-herpetic neuralgia (PHN), characterized by persisting neuropathic pain in the affected dermatome after the rash recedes. The immune system is more compromised in older people, which leads to an increase in the incidence of HZ and PHN. Several studies have revealed that HZ or PHN is associated with an increased risk of malignancy in immune-suppressed patients. An 83-year-old man visited our pain clinic with facial pain 6 months after he was diagnosed with recurred HZ on the right V1 dermatome. He was diagnosed with HZ on the right C2 dermatome 5 years ago. He could not perform a right lateral gaze for the past 3 months. Moreover, the symptoms did not improve and the pain was aggravated on the face and head. We considered two possibilities: HZ affecting motor neuron and occult malignancy. Brain magnetic resonance imaging and magnetic resonance angiography showed a mass lesion that should have been differentiated, and his blood was positive for prostate specific antigen. The probability of occult malignancy should be taken into account in elderly patients with HZ or PHN.