Incidence of herpes zoster and postherpetic neuralgia in Italian adults aged ≥50 years: A prospective study.

ABSTRACT

Herpes zoster (HZ) mainly affects older adults and immunocompromised individuals and is usually characterized by a unilateral painful skin rash. Its most common complication, postherpetic neuralgia (PHN), may cause chronic debilitating pain lasting for months or years. This study (ClinicalTrials.gov Identifier NCT01772160) aimed to estimate the HZ incidence and the proportion of HZ patients with PHN in the Italian population aged 50 years or older. From 2013 to 2016, HZ-patients were recruited when presenting with acute HZ at 75 reporting general practitioners in Italy, covering 43,875 persons aged ≥50 years. PHN was defined as 'worst pain' rated ≥ 3 on the Zoster Brief Pain Inventory persisting or appearing over 90 days after rash onset. The overall HZ incidence rate per 1000 person-years (PY) was estimated as 6.46 (95% confidence interval [CI] 5.99-6.95), increasing with age to 9.12/1000 PY (95% CI 7.50-10.99) in 75-79 year-olds. Among 391 HZ-patients who completed the study, the overall proportion with PHN was 10.23% (95% CI 7.41-13.67) and the highest proportion was 15.56% (95% CI 6.49-29.46) for the 75-79 year-olds. Among the 128 patients (32.7%) who reported at least one pre-existing medical condition, 35.9% reported diabetes mellitus and 32.0% reported emotional problems, stress or depression. The study confirms previous findings that HZ and PHN cause an important clinical burden in older Italian adults. It also confirmed the age-related increasing risk of HZ and PHN.