About Post Herpetic Neuralgia
Approximately 20% of those who experience a shingles (herpes zoster) outbreak develop pain in the nerve endings one or more months after the episode has healed. This condition is called post herpetic neuralgia, or PHN. The pain often returns sporadically at unknown intervals. This can also occur from those who have experienced an outbreak of genital herpes or oral herpes (cold sores).
The pain of PHN results from peripheral nerve injury, typically occurring at the site of the initial episode. The affected area is extremely sensitive to any stimuli; even the pressure of clothing can produce unbearable pain. Spontaneous remission of PHN occurs for many patients within a few months. In some cases, the pain can last for several years.
PHN has been difficult to treat. Antivirals and other drugs such as corticosteroids and local and regional anesthesia have been tried without much success, although some drugs may reduce the duration of pain. Western medications are therefore based on managing the neuralgia once it develops.