What is postherpetic neuralgia (PHN)?
Postherpetic neuralgia (PHN) is a painful, long-lasting condition. It is more likely to develop in older patients after an attack of shingles (varicella-zoster virus). Even after the severe rash of shingles lessens, pain can continue in shingles-affected areas. This condition is known as PHN when the pain continues for longer than 4 months after the onset of the rash. PHN occurs most often in older adults and in patients whose immune systems have been compromised.
Symptoms and Causes
What causes postherpetic neuralgia (PHN)?
The pain of PHN, which occurs in the same area as the pain and rash of shingles, results from damage to nerve fibers during the shingles infection. Shingles is caused by a recurrence of the varicella-zoster virus, the same virus that causes chickenpox. Anyone who has had chickenpox can get shingles, but the disorder is most common in people over the age of 60.
What are the symptoms of postherpetic neuralgia (PHN)?
In PHN, pain is intense and may be described as burning, stabbing, or gnawing. Affected areas of the body may be hypersensitive or may have decreased sensation. Areas formerly affected by shingles may show evidence of skin scarring.
Diagnosis and Tests
How is postherpetic neuralgia diagnosed (PHN)?
PHN usually is diagnosed when a patient’s pain lasts more than 30 days after an attack of shingles or for more than 90 days after rash onset.
Management and Treatment
How is postherpetic neuralgia (PHN) treated?
Patients with PHN should receive treatment to control serious symptoms and prevent problems. PHN is treated with medications including:
- Capsaicin cream and patch
- Lidoderm cream and patch
In some cases, there is a tendency for PHN to improve over time without treatment, but that improvement usually levels off after 1 year from the start of symptoms.