Early antiviral treatment fails to completely prevent herpes-related pain

Objectives. - Antiviral therapy does not completely relieve herpes zoster (HZ)-related pain, including post-herpetic neuralgia (PHN). The 12-month longitudinal prospective observational ARIZONA study was conducted in primary care in France between November 20, 2006 and September 12, 2008. The ARIZONA study included data from 1358 patients 50 years of age or more, presenting with acute eruptive HZ. This article focuses on the relationship between antiviral therapy and HZ-related pain in this large population.Patients and methods. - Six hundred and forty-four family physicians (FPs) consecutively included all patients 50 years of age or more presenting with acute HZ in the eruptive phase. The FP documented every patient's demographic and medical characteristics, HZ characteristics, and prescribed drugs at inclusion, and the presence of HZ-related pain on day 15 and at months 1, 3, 6, 9, and 12.Results. - One thousand two hundred and fifty-eight (92.6%) of the 1358 included patients (mean 67.7 years [SD 10.7]; 62.2% female patients) were given antiviral drugs. The prevalence of HZ-related pain was 43.6%, 27.0%, 11.7%, 8.7%, 7.4%, and 6.0%, on day 15 and at months 1, 3, 6, 9, and 12, respectively. HZ-related pain was at least as frequent in patients treated by antiviral therapy within 72 hours following HZ-rash onset as in patients treated later or who did not receive antiviral treatment, and more frequent in patients whose diagnosis was made within 24 hours following HZ-rash onset.Conclusions. - Antiviral therapy, even early, does not prevent HZ-related pain and PHN, probably because patients quickly identified and treated were those with severe forms and potentially at high risk of pain. Preventive strategies are thus needed.