This is a prospective, single-arm, open-label, pilot clinical study to evaluate the efficacy and safety of topical 10% high-concentration 35 kDa hyaluronan (HA35) gel in subjects with herpes zoster-associated pain (ZAP). Eligible participants will receive a single topical application of the study gel. The primary objective is to assess rapid pain reduction within 2 minutes and 24hours after application. Secondary objectives include evaluation of analgesic duration, local tolerability, erythema improvement, and overall safety throughout the observation period. This is a minimal-risk, non-pharmacological supportive care intervention.

This prospective, single-center, single-arm, open-label pilot clinical study investigates the analgesic efficacy and safety of topical 10% high-concentration 35 kDa hyaluronan (HA35) gel for the management of herpes zoster-associated pain (ZAP), including acute zoster pain and postherpetic neuralgia (PHN).

Eligible subjects will receive a single topical application of HA35 gel to the affected skin area. Pain intensity will be evaluated using a 0-10 Numeric Rating Scale (NRS) at baseline, 2 minutes, 20 minutes, 4 hours, 8 hours, 12 hours, and 24 hours after application.

Local skin reactions, erythema, swelling, and all adverse events will be monitored for safety assessment.

This study uses a non-invasive, non-pharmacological topical intervention with minimal risk to participants. All procedures will be conducted in accordance with the Declaration of Helsinki, and written informed consent will be obtained from all subjects prior to enrollment.

Inclusion Criteria:

• Age 18-85 years, male or female
• Clinically diagnosed with herpes zoster-associated pain (acute ZAP or PHN)
• Baseline pain NRS score ≥5
• Ability to understand and complete NRS assessments
• Signed written informed consent

Exclusion Criteria:

• Acute bacterial skin infection at the application site
• Use of topical analgesics or antiviral therapy within 24 hours
• Systemic analgesic use within 6 hours
• Known hypersensitivity to hyaluronan or gel components
• Pregnant or lactating women
• Severe systemic disease or malignant tumor