Effectiveness and safety of lidocaine patch 5% to treat herpes zoster acute neuralgia and to prevent postherpetic neuralgia.

Herpes zoster is often associated to acute neuralgia and postherpetic neuralgia (PHN). Their therapeutic management is still challenging: among therapeutic options, lidocaine patch 5% was rarely used in acute neuralgia on lesional skin, and its efficacy to prevent PHN was never studied. The efficacy and tolerability of lidocaine patch 5% was evaluated in 38 patients with acute neuralgia (19) and PHN (19). Pain intensity was investigated using DN4 questionnaire and NRS-11 scale at baseline and at week 2, 4, and 8. The use of rescue therapy was also evaluated. A significant reduction of DN4 and NRS-11 was observed already at W2, with further improvement at W4 and W8. A complete response to treatment (DN4 and NRS-11 = 0) at week 8 was higher in patients with acute neuralgia (63.2%) than PHN (31.6%). Rescue therapy gradually decreased in acute neuralgia patients from week 2 (57.9%) to week 8 (10.5%), with only two patients needing neuroleptics. In PHN patients rescue therapy remained stable (68.4%). According to our results, lidocaine patch 5% applied on lesional skin was well tolerated and ensured a rapid pain relief in acute neuralgia; if early used, it prevented PHN in almost all patients.