Post-herpetic neuralgia (PHN) is the most common complication of herpes zoster (HZ) and is difficult to treat. The role of antiviral agents and nonpharmacologic procedures in preventing PHN is not entirely clear. Recent retrospective study showed that transcutaneous electrical nerve stimulation (TENS) may completely prevent PHN. The aim of our study was to identify predictors for PHN and evaluate the treatment with antiviral agents and TENS.
We conducted a multicenter prospective, randomized intervention study in patients with a new onset of HZ. Immunocompromised patients were excluded. Patients were randomly assigned to four groups (TENS, Antiviral agents, TENS and Antiviral agents, and Control Group). At the inclusion, the following criteria were recorded: age, gender, duration of pain before the onset of the rash, the number of efflorescence, the intensity of pain, and the analgesic prescribed. During the follow-up, we recorded a spontaneous pain sensation, pain intensity, and presence of allodynia, hyperalgesia, or paraesthesia.
With each additional year of age, the odds for the presence of PHN with unchanged values of other predictors increase (odds ratio (OR) = 1.03 [1.01; 1.05], p = 0.001). The same is true for the initial intensity of the pain (OR = 1.25 [1.09; 1.43], p = 0.002). The odds for acute and subacute herpetic neuralgia are greater than for PHN. The odds for subacute herpetic neuralgia are the lowest in the group treated with TENS (OR = 0.15 [0.05; 0.47], p = 0.001).
PHN cannot be completely prevented. TENS as a single therapy was found the most successful among the tested treatments in reducing the incidence of subacute herpetic neuralgia.