Post-herpetic Neuralgia: a Review

Post-herpetic neuralgia (PHN) is a chronic neuropathic pain condition that persists 3 months or more following an outbreak of shingles. Shingles, also known as acute herpes zoster, is associated with the reactivation of the dormant varicella zoster virus in an individual who has experienced chicken pox. PHN is associated with persistent and often refractory neuropathic pain. Patients may experience multiple types of pain including a constant deep, aching, or burning pain; a paroxysmal, lancinating pain; hyperalgesia (painful stimuli are more painful than expected); and allodynia (pain associated with typically non-painful stimuli). The pharmacological treatment of PHN may include a variety of medications including alpha-2 delta ligands (gabapentin and pregabalin), other anticonvulsants (carbamazepine), tricyclic antidepressants (amitriptyline, nortriptyline, doxepin), topical analgesics (5 % lidocaine patch, capsaicin) tramadol, or other opioids. The considerable side effect profiles of the commonly used oral medications often limit their practical use, and a combination of both topical and systemic agents may be required for optimal outcomes. Physicians and other treatment providers must tailor treatment based on the response of individual patients.