Postherpetic neuralgia. A review.

Postherpetic pain persisting one month or longer occurs in 9% to 14% of patients with herpes zoster, diminishing with time. The incidence and duration are directly related to age. The pathologic features have been described but the pathogenesis of postherpetic neuralgia is unknown. Treatment remains difficult. It is reasonable to hope for a reduction in pain from severe to mild in two of three cases. There is evidence to support the use of low doses of tricyclic antidepressants, especially amitriptyline hydrochloride, with gradual small increments, and also the use of phenothiazines. Corticosteroids may exert a preventive effect when used in the acute phase. There is some support for the use of local physical modalities. Neurosurgical procedures are a possibility in failed medical cases. Controlled studies of newer approaches are necessary.