Postherpetic Neuralgia

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

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

Severity of pain correlates with intensity of zoster outbreak

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

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