Postherpetic neuralgia

Skin | Dermatology | Postherpetic neuralgia (Disease)


Description

Neuralgia is severe pain along the course of a nerve. PHN may lead to fatigue, insomnia, anxiety, and depression. Because of the severity and complexity of the disease, treatment is initiated at the onset of the rash and may be necessary months to years later. Topical analgesics are commonly used for the short-term relief of PHN.

Causes and Risk factors

The pain occurs because of a change in neurological structure or function due to irritation or damage of a nerve. Postherpetic neuralgia is a painful condition which affects the nerve fibers and skin.

Postherpetic neuralgia is a complication of shingles. The persistent pain associated with herpes zoster is variable in nature, and can be characterized as any of the following: burning background pain with fluctuating severity; sudden, sharp shooting pain; mechanical or thermal allodynia (pain produced by non-noxious stimulus). As a result of this severe, often debilitating pain, a patient’s quality of life is often adversely affected. In addition to interfering with activities of daily living,

Diagnosis and Treatment

Capsaicin cream, applied 3-4 times daily, is commonly prescribed and functions to reduce pain by depleting substance P via neurogenic vasodilatation. Side-effects include intolerable burning pain. A topical 5% lidocaine patch can also provide relief of PHN for approximately 12 hours after application.

Side-effects are mild and include local skin reactions such as erythema. Tricyclic antidepressants (TCAs) have been used extensively for the treatment of PHN, as they have been shown to provide moderate-to-excellent pain relief.

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