ascorbic-acid and Neuralgia--Postherpetic

Herpes zoster (HZ) is an acute inflammatory neurocutaneous disease caused by the reactivation of varicella-zoster virus. It is estimated that the incidence of postherpetic neuralgia following HZ is 10-20%. The leading risk factors of the prognosis are aging and immunity dysfunction. Vitamin C plays a pivoted role in enhancing white blood cell function. Epidemiological evidence and clinical studies have indicated an association between pain and suboptimal vitamin C status. At present, vitamin C has been used as an additional option in the treatment of HZ-associated pain. Despite the current controversy, case reports and randomized controlled studies have indicated that both acute- and postherpetic neuralgia can be dramatically alleviated following intravenous vitamin C infusions.. The use of vitamin C appears to be an emerging treatment alternative for attenuating HZ and PHN pain. Hence, we recommend the addition of concomitant use of intravenously administered vitamin C into therapeutic strategies in the treatment of HZ-associated pain, especially for therapy-resistant cases. Furthermore, animal studies are required to determine analgesic mechanisms of vitamin C, and more randomized clinical trials are essential to further determine the optimal dose and timing of administration of vitamin C.

Topics: Administration, Intravenous; Aged; Ascorbic Acid; Female; Herpes Zoster; Herpesvirus 3, Human; Humans; Infusions, Intravenous; Male; Neuralgia, Postherpetic

Plasma vitamin C concentrations have been suggested to be related to pain modulation in postherpetic neuralgia (PHN), an intractable neuropathic pain syndrome. In this study, we first compared plasma concentrations of vitamin C between healthy volunteers and PHN patients and then designed a symptom-based and mechanism-based approach to assess the analgesic effect of intravenous vitamin C on spontaneous and brush-evoked pain.. Study 1 was cross-sectional that enrolled 39 healthy volunteers and 38 PHN patients. Study 2 was a double-blinded, placebo-controlled intervention study, which comprised 41 patients randomly allocated into the ascorbate group and placebo. Each patient received normal saline infusion with or without ascorbate on days 1, 3, and 5 and answered questionnaires that included side effects; numeric rating pain scale (NRS) on spontaneous and brush-evoked pain on days 1, 3, 5, and 7; and patient global impression of change on spontaneous and brush-evoked pain on day 7.. Study 1 revealed that plasma concentrations of vitamin C were significantly lower in patients with PHN than in healthy volunteers (P<0.001). Study 2 showed that ascorbate treatment effectively restored plasma vitamin C concentrations in the patients and decreased spontaneous pain by 3.1 in NRS from baseline to day 7, as compared with a decrease of 0.85 in NRS by placebo treatment (P<0.001). Conversely, ascorbate treatment did not significantly affect brush-evoked pain. Ascorbate treatment also resulted in a better efficacy than placebo in patient global impression of change on spontaneous pain (P<0.001) on day 7 and did not affect brush-evoked pain. No side effects were observed.. Plasma vitamin C status plays a role in PHN, and intravenous ascorbate helps relieve spontaneous pain in PHN.

Topics: Adult; Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; Cross-Sectional Studies; Double-Blind Method; Female; Humans; Injections, Intravenous; Male; Middle Aged; Neuralgia, Postherpetic; Pain Measurement; Pain Threshold; Physical Stimulation; Statistics, Nonparametric; Time Factors

Vitamin C deficiency increases the risk of postherpetic neuralgia (PHN). In this cross-sectional study, the relationships among plasma vitamin C concentrations, pain and Leeds assessment of neuropathic symptoms and signs (LANSS) items were investigated during their first pain clinic visit of 120 PHN patients. The factors associated with vitamin C deficiency were determined. Independent predictors of vitamin C deficiency were presented as adjusted odds ratios (AOR) and 95% confidence intervals (CI). The patients had a high prevalence (52.5%) of vitamin C deficiency. Their plasma vitamin C concentrations were negatively associated with spontaneous pain and tingling, prickling or pins and needles sensation according to the LANSS questionnaire. Based on the receiver operator characteristic curve, the cutoffs for plasma vitamin C to predict moderate-to-severe and severe symptoms of sharp sensation were <7.05 and <5.68 mg/L, respectively. By comparison, the patients well-nourished with vitamin C had lower incidences of sharp sensations, sharp pain, and reddish skin. Multivariate analyses revealed that vitamin C deficiency was associated with the low intake of fruit/vegetables (AOR 2.66, 95% CI 1.09-6.48,

Topics: Adult; Aged; Aged, 80 and over; Ascorbic Acid; Ascorbic Acid Deficiency; Cross-Sectional Studies; Diet; Diet Surveys; Female; Humans; Incidence; Male; Middle Aged; Multivariate Analysis; Neuralgia, Postherpetic; Odds Ratio; Pain Measurement; Paresthesia; Prevalence; Prospective Studies; Risk Factors; ROC Curve; Surveys and Questionnaires; Young Adult

Acute herpetic neuralgia (AHN) due to a reactivated varicella zoster virus infection is a common problem. Furthermore, about 18% of all patients with confirmed herpes zoster (HZ) develop postherpetic neuralgia (PHN). The leading factors of the prognosis and persistence of symptoms are patient age and the size of the lesions. Animal studies came to a similar conclusions that in both AHN and PHN, inflammatory cytokines such as IL-6 and IL-8 could serve as predictive markers and that a positive influence of vitamin C administration, by modifying cytokine metabolism, could be demonstrated.. Two patients (females aged 67 and 53 years) from an average and unselected patient group of a general practice with confirmed AHN were observed in the course of their illness. They received the basic analgesic (according to the WHO step scheme) and viral-static therapy. Furthermore, 15 g of vitamin C was administered intravenously every second day over a period of two weeks. Sudden and total remission of the neuropathic pain (measured on the basis of the visual analogous-scale, VAS) could be observed. Remission of the cutaneous lesions was noted within 10 days.. The use of the vitamin C appears to be an interesting component of alternative therapeutic strategies in the treatment of HZ. Especially for therapy-resistant cases of PHN, vitamin C administration should be examined as an additional option. To test and confirm the clinical findings, randomized clinical studies concerning the use of vitamin C in the concomitant treatment of zoster-associated neuralgia should be performed.

Topics: Aged; Ascorbic Acid; Female; Humans; Middle Aged; Neuralgia, Postherpetic

Topics: Aged; Ascorbic Acid; Humans; Injections, Intravenous; Male; Neuralgia, Postherpetic