Postherpetic Neuralgia

Key Features

• Past history of herpes zoster (shingles)

• Occurrence of pain for months or years in the same dermatomal distribution as was affected by the herpes zoster

Clinical Findings

• Severe pain, sometimes burning or tingling and quite disabling, occurs in areas of prior shingles

• Severity of pain correlates with intensity of zoster outbreak

Diagnosis

• A history of shingles and the presence of cutaneous scarring resulting from shingles aid in the diagnosis

Treatment

• Acyclovir (800 mg five times daily) or valacyclovir (1000 mg three times daily) reduces the incidence of postherpetic neuralgia by almost half when given within 72 of rash onset

• Management of the established complication is with simple analgesics

• If simple analgesics fail to help, a trial of a tricyclic antidepressant (eg, amitriptyline or nortriptyline, up to 100–150 mg/day) is often effective

• Other patients respond to gabapentin (up to 3600 mg/day) or pregabalin (up to 300 mg/day)

• Topical application of capsaicin cream or topical lidocaine patch may be helpful