Approximately 90% of the adult population have been infected with VZV and are thus at risk for the development of herpes zoster (shingles). It is estimated that one in four adults will develop shingles in their lifetime.

Typically shingles occurs on the trunk, or face, on either the left or right side of the body, not both sides. A complication of shingles, PHN is a painful condition that affects the nerve fibres and skin.

After recovery from chickenpox, the virus can be dormant in a nerve root. Reactivation of latent infection causes shingles – a localised, painful blister-like rash, in the area supplied by that nerve

CAUSE

VZV causes chickenpox and shingles. Chickenpox follows initial exposure to the virus and is typically a relatively mild, self-limited childhood illness. Reactivation of the dormant virus results in the characteristic painful dermatomal rash of shingles, which is often followed by pain in the distribution of the rash (post-herpetic neuralgia).

POST-HERPETIC NEURALGIA

“The most important complication of shingles is post-herpetic neuralgia (PHN)” said clinical virologist Dr Allison Glass. “This is chronic nerve pain over the affected site that persists for at least three months after the rash resolves. The pain may however last indefinitely and can severely impact on quality of life. PHN is more common if shingles occurs after the age of 50 years.” Patients describe the pain as an intense sensation of tingling, burning, and shooting that doesn’t let up.

TREATMENT

No single treatment relieves post-herpetic neuralgia for everyone. It often takes a combination of treatments to reduce the pain. According to current SA clinical practice guidelines, systemic reviews concur that gabapentin, pregabalin, TCAs, and lidocaine patches (now available in SA) have strong evidence of efficacy in PHN.