The cause of postherpetic neuralgia is the varicella zoster virus that remained after the initial chickenpox infection and revived again with the shingles infection. The damaged nerve fibers of the skin continue to send pain signals to the brain, long after the blisters have healed.

Postherpetic neuralgia has the following symptoms:

• occurs at the site of the initial shingles outbreak — usually on the trunk, but sometimes on the face
• the chronic pain can be described as unbearable, aching, stabbing, burning or sharp
• pain can be triggered by a light touch — such as clothing brushing against the area
• less commonly, itchiness or numbness may occur

Other complications that often arise from postherpetic neuralgia include:

• depression that can come from a person isolating themselves to avoid pain triggers
• fatigue from sleep difficulties associated with the neuralgia
• concentration problems
• loss of appetite