Keywords: PHI, postherpetic itch; PHN, postherpetic neuralgia; PP-NRS, peak pruritus numerical rating scale; chronic pruritus; herpes zoster; intranasal butorphanol; itch; neuropathic pruritus; opioid; postherpetic itch; postherpetic neuralgia; pregabalin; pruritus; risperidone; scratch; shingles; ulcer.