BackgroundData on the epidemiology and cost of herpes zoster (HZ) and post-herpetic neuralgia (PHN) in Italy are limited. This retrospective, population-based study was designed to determine the incidence of HZ and the proportion developing PHN in Italy and the associated medical resource utilisation and costs. It focused primarily on immunocompetent patients aged ≥50 years who would be eligible for preventive vaccination.MethodData were extracted from a primary-care database and national hospital-discharge records covering four major regions in Italy for 2003-2005. Cases of HZ and PHN (1 and 3 months' duration; PHN1 and PHN3) were identified by ICD9-CM codes and, additionally for PHN, prescription of neuropathic pain medication.ResultsOver 3 years, 5675 incident cases of HZ were documented in adults, of which 3620 occurred in immunocompetent patients aged ≥50 years (incidence of 6.31 per 1000 person-years [95% CI: 6.01-6.62]). Of the immunocompetent patients aged ≥50 years with HZ, 9.4% (95% CI: 8.2-10.7) and 7.2% (95% CI: 6.2-8.2) developed PHN1 and PHN3, respectively. Increasing age, female sex, and being immunologically compromised conferred increased risk for both HZ and PHN. Overall, about 1.3% of HZ and almost 2% of PHN cases required inpatient care, with 16.9% of all HZ-related hospitalisations due specifically to PHN. In patients aged ≥50 years, mean stay was 7.8 ± 5.4 days for HZ and 10.2 ± 8.6 days for PHN, and direct costs associated with inpatient care were more than 20 times outpatient costs per HZ case (mean ± SD: €2592 ± €1313 vs. €122.68 ± €97.51) and over 5 times more per episode of PHN (mean ± SD: €2806 ± €2641 vs. €446.10 ± €442.97). Total annual costs were €41.2 million, of which €28.2 million were direct costs and €13.0 million indirect costs.ConclusionsThis study, the largest to date on the epidemiology and economic impact of HZ and PHN in Italy, confirms the considerable disease and economic burden posed by HZ. As HZ and PHN disproportionately affect the elderly, without intervention this problem is likely to grow as the proportion of elderly in the Italian population continues to increase.

Postherpetic neuralgia is an exceptionally drug-resistant neuropathic pain. To investigate the pathophysiological mechanisms underlying postherpetic neuralgia we clinically investigated sensory disturbances, pains and itching, with an 11-point numerical rating scale in 41 patients with ophthalmic postherpetic neuralgia. In all the patients we recorded the blink reflex, mediated by non-nociceptive myelinated Abeta-fibers, and trigeminal laser evoked potentials (LEPs) related to nociceptive myelinated Adelta- and unmyelinated C-fiber activation. We also sought possible correlations between clinical sensory disturbances and neurophysiological data. Neurophysiological testing yielded significantly abnormal responses on the affected side compared with the normal side (P<0.001). The blink reflex delay correlated with the intensity of paroxysmal pain, whereas the Adelta- and C-LEP amplitude reduction correlated with the intensity of constant pain (P<0.01). Allodynia correlated with none of the neurophysiological data. Our study shows that postherpetic neuralgia impairs all sensory fiber groups. The neurophysiological-clinical correlations suggest that constant pain arises from a marked loss of nociceptive afferents, whereas paroxysmal pain is related to Abeta-fiber demyelination. These findings might be useful for a better understanding of pain mechanisms in postherpetic neuralgia.

Post-herpetic neuralgia is the most challenging and debilitating complication of herpes zoster in the immunocompetent host. Because the effect of treatment is disappointing once the syndrome has developed, it is important to know which factors predict post-herpetic neuralgia occurrence to facilitate selection of herpes zoster patients with a higher risk of developing neuralgia and undertake preventative strategies. The present study aimed at identifying demographic, clinical and psychosocial correlates of postherpetic neuralgia in a sample of 219 immunocompetent patients, who were examined by dermatologists in private practice in Italy and who completed a questionnaire designed to evaluate their clinical and psychosocial profile at the time of clinical diagnosis of herpes zoster and at a follow-up visit 6 months later. In a univariate analysis, post-herpetic neuralgia was associated significantly with older age, longer duration of prodromal pain, greater acute pain intensity, greater extent of rash, presence of abnormal sensations and use of systemic antiviral therapy. Compared to the values at herpes zoster onset, at the follow-up visit patients with post-herpetic neuralgia presented with similar high mean scores of pain intensity, anxiety and depression and greatly reduced quality of life, whereas patients without neuralgia presented with improved scores. In a multivariate model, older age, greater acute pain intensity, greater extent of rash and longer duration of prodromal pain were independently associated with postherpetic neuralgia. The results of this study may help physicians to identify patients with a higher risk of developing post-herpetic neuralgia and undertaking preventative strategies.

Tapentadol prolonged release was well tolerated and effective for managing severe, chronic low back pain with or without a neuropathic pain component.