Herpes zoster is a viral infection which may affect the cranial or peripheral nerves. The virus may lie dormant (inactive) in the nerves for many decades, and typically reactivates in the elderly.

Shingles presents with constant burning pain and is followed a few days later by redness of the skin and a characteristic vesicular rash. At that stage the affected skin is hypersensitive and may be numb.

Antiviral medications should be commenced as soon as possible, to both reduce the pain and minimise the chance of developing post-herpetic neuralgia.