Clinical features and pathophysiologic mechanisms of postherpetic neuralgia.

Postherpetic neuralgia is an unfortunate aftermath of shingles, and is most likely to develop, and most persistent, in elderly patients. Pain, allodynia, and sensory loss in the affected dermatome are the cardinal manifestations of the disorder. The pathophysiology of postherpetic neuralgia is not well known, but recent observations suggest multiple changes in the afferent pathways at both peripheral and central nervous system levels.