Post-herpetic neuralgia (PHN) is caused by damage that occurs to the peripheral nerve fibers during a shingles infection. On average, one out of every five patients with shingles develops PHN. However, the risk of having the condition increases with age — older people who have suffered from shingles have as much as a 50 percent chance of developing PHN.

Each year, about 1 million people in North America develop shingles, also called herpes zoster, a painful skin rash caused by the reactivation of a dormant chicken pox virus. Roughly 10 percent of those with shingles suffer long-lasting pain called post-herpetic neuralgia (PHN). Although most people have shingles for about a month, the pain and skin sensitivity of PHN can continue for months or even years.

Pain associated with PHN can be very intense, often described by patients as deep, aching and unbearable. In some cases, even a light touch, like the pressure of a shirt or gust of wind, can cause intense pain.

Because the pain of PHN can be so awful, it interferes with a person’s life. Some PHN patients have to stop their normal activities for months. Also, depression is common because of the severe pain and social isolation that can occur.

Treatment for post-herpetic neuralgia depends on the type and characteristics of pain experienced by the patient. Pain control is essential to a patient’s comfort level. Treatments include:

• Antiviral agents given at the onset of attacks of shingles to shorten the clinical course and to help prevent complications such post-herpetic neuralgia. However they have no role to play following the acute attack if PHN has become established
• Analgesics
• Pain modification therapy such as antidepressants and anticonvulsants
• Corticosteroids

Although some people must live with PHN the rest of their lives, most people can expect the condition to gradually disappear on its own within five years.