Herpes zoster (HZ) is characterized by a painful dermatomal rash and significantly affects quality of life, with acute pain increasing the risk of postherpetic neuralgia. Although early antiviral therapy limits viral replication, its analgesic effect is insufficient, and many patients experience inadequate relief despite stepwise use of non-opioids and opioids. Topical NSAIDs offer a promising alternative by delivering localized analgesia with reduced systemic exposure. Therefore, investigators hypothesize that flurbiprofen patch may effectively reduce the severity of HZ pain without significantly increasing adverse events.