Post-herpetic neuralgia

Neuropathic pain is defined as spontaneous pain and hypersensitivity to pain associated with damage to or pathologic changes in the peripheral nervous system as in painful diabetic peripheral neuropathy (DPN), acquired immunodeficiency syndrome (AIDS), polyneuropathy, post-herpetic neuralgia (PHN) or pain originating in the central nervous system (CNS), that which occurs with spinal cord injury, multiple sclerosis, and stroke. Functional pain, a relatively newer concept, is pain sensitivity due to an abnormal processing or function of the central nervous system in response to normal stimuli. Several conditions considered to have this abnormal sensitivity or hyperresponsiveness include fibromyalgia and irritable bowel syndrome. 

DPN, diabetic peripheral neuropathy PHN, post-herpetic neuralgia TCA, tricyclic antidepressant. 

Later in life, approximately 15% of the population will develop herpes zoster. Herpes zoster is the reactivation of latent varicella zoster virus in the sensory ganglia. Approximately 20% of persons with herpes zoster will develop post-herpetic neuralgia, which is a painful debilitating condition that can persist for months after resolution of the herpes zoster rash. 

Other Uses in Geriatric Patient Neuropathic Pain, Post-Herpetic Neuralgia, Essential Tremor... 

Treatment of varicella (chickenpox) and herpes zoster (shingles) infections. Early treatment of shingles with acyclovir can reduce the incidence of post-herpetic neuralgia (zosterassociated pain). 

Eide, P. K., Jorum, E., Stubhaug, A., Bremmes, J., Breivik, H. Relief of post-herpetic neuralgia with the N-methyl-D-aspartic acid receptor antagonist ketamine a double-blind, cross-over comparison with morphine and placebo, Pain 1994, 58, 347-354. 

Watson, C.P., Evans, R.J., Watt, V.R. Post-herpetic neuralgia and topical capsaicin, Pain 1988, 33, 333-340. 

Pain resulting from non-inflammatory dysfunction of the peripheral or central nervous system without nociceptor stimulation or trauma. Examples include post-herpetic neuralgia, complex regional pain syndromes, phantom pain and trigeminal neuralgia. 

Klepstad P. and Borchgrevink P. C. (1997). Four years treatment with ketamine and a trial of dextromethorphan in a patient with severe post-herpetic neuralgia. Acta Anaesthesiol. Scand. 41 422-426. 

A large, multicenter, randomized, double-blind, placebo-controlled study evaluated the treatment effect of famciclovir on herpes zoster and post-herpetic neuralgia in immunocompetent participants and found faster resolution of post-herpetic neuralgia, faster lesion healing, and a safety profile similar to the placebo group (Tyring et al.). 

A 60-year-old woman with post-herpetic neuralgia developed asterixis after having taken gabapentin for 4 days (18). The authors proposed that the mechanism was GABAergic. 

The analgesic effects of single and repeated applications of Emla over six consecutive days have been studied in 11 patients with post-herpetic neuralgia (20). There was no evidence of systemic adverse effects, but four patients developed mild erythema at 30 minutes, which may have been due to the occlusive dressing, and one patient had pruritus on day 7. 

Altai N, Brasseur L, Chauvin M, Bouhassira D. Effects of single and repeated applications of a eutectic mixture of local anaesthetics (EMLA) cream on spontaneous and evoked pain in post-herpetic neuralgia. Pain 1999 81(l-2) 203-9. 

Indications Neuropathy, Post-herpetic neuralgia, Partial epilepsy... 

Treatment recommendations for post herpetic neuralgia were published in 1996 by Kost and colleagues. Several reviews on the treatment of back pain have been recently published. Treatment guidelines for migraine were published in 1999. In 1998, a review of the treatment of bum pain was published by Ulmer and colleagues. 

Eide, K., Stubhaug, A., Oye, I., Breivik, H., 1995. Continuous subcutaneous administration of the N-methyl-o-aspartic acid (NMDA) receptor antagonist ketamine in the treatment of post-herpetic neuralgia. Pain 61, 221-228. 

A study confirming the value of carbamazepine and clomipramine in the treatment of post-herpetic neuralgia found that carbamazepine appeared to raise both clomipramine plasma levels and those of its major metabolite (desmethylclomipramine). ... 

Gerson GR, Jcmes R , Luscombe DK. Studies on the conccxnitant use of caitama pine and clomiiramine for the relief of post-herpetic neuralgia. PostgradMedJ ( 9TT) 53 (Suppl 4), 104-9. 

Morris, G. C., Gibson, S. J., and Hehne, R. D. 1995. Capsaidn-induced flare and vasodilatation in patients with post-herpetic neuralgia. Pain 63 93—101. Laskaridou-Monnerville, A. 1999. Determination of capsaicin and dihydrocapsaicin by micellar electrokinetic capillary chromatography and its application to various species of Capsicum, Solanaceae. J. Chromatogr. A. 838 293-302. 

Garcia JB, Ferro LS, Carvalho AB, da Rocha RM, de Souza LM. Severe carbamazepine-induced cutaneous reaction in the treatment of post-herpetic neuralgia. Case report. Rev Bras Anestesiol 2010 60(4) 429-37. 

Capsaicin cream 0.075 % Pain relief at peripheral neuropathy e.g. post-herpetic neuralgia or shingles, reduction of itching and inflammation at psoriasis... 

Bernstein JE (1989) Treatment of chronic post-herpetic neuralgia with topical capsaicin. Am J Dermatol 21 265-270... 

---