Intradermal Exosomes, Platelet-Rich Plasma, and Steroids for Post-Herpetic Neuralgia

A Comparative Study of Intradermal Injection of Exosomes, Platelet-Rich Plasma and Steroids in the Treatment of Post-Herpetic Neuralgia

This randomized controlled clinical trial will evaluate and compare the efficacy and safety of intradermal injection of exosomes, platelet-rich plasma, and corticosteroid in patients with post-herpetic neuralgia. Forty-five adult patients with dermatomal pain persisting for at least 90 days after herpes zoster will be enrolled from outpatient clinics. Participants will be assigned to one of three groups: intradermal exosome injection, intradermal autologous platelet-rich plasma injection, or intradermal triamcinolone acetonide injection. Each group will receive four treatment sessions every two weeks. Outcomes will include pain severity, neuropathic pain characteristics, quality of life, patient satisfaction, and adverse effects, assessed at baseline, at the final session, and during follow-up visits at 3 and 6 months after the last session.

Study Overview

• Status: Recruiting
• Conditions: Postherpetic Neuralgia ( PHN )
• Intervention / Treatment: Biological: Exosomes; Biological: PRP; Drug: Corticosteroids

• Study Type: Interventional
• Enrollment (Estimated): 45
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: mona Elradi; Phone Number: +201067070550; Email: monaelradi@medicine.zu.edu.eg

Study Locations

• Egypt
  • Zagazig
    • Zagazig, Zagazig, Egypt, 44519
      • Recruiting
      • Zagazig university hospitals
      • Contact: mona Elradi; Phone Number: 01067070550; Email: monaelradi@medicine.zu.edu.eg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients with post-herpes zoster persistent dermatomal pain consistent with post-herpetic neuralgia for at least 90 days.

Male or female patients. Age 18 years or older. Willingness to comply with study procedures and attend follow-up visits. Ability and willingness to provide written informed consent

Exclusion Criteria:

• History of hypersensitivity to any of the study treatments. Pregnancy. Any type of skin infection involving the affected dermatome. Immunocompromised patients, including patients with cancer or HIV. Patients with bone marrow aplasia. Patients with known bleeding tendency, platelet dysfunction, or thrombocytopenia, defined as platelet count less than 150 × 10⁹/L.

Regular use of anticoagulant or antiplatelet drugs.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Corticosteroids	Drug: Corticosteroids; Intradermal triamcinolone acetonide 10 mg/mL, 0.1 mL per 1 cm² square of the affected dermatome, every two weeks for four sessions
Experimental: Exosomes; Participants will receive intradermal injections of exosome product into the affected dermatome. The dermatome will be marked and divided into 1 cm² squares, and 0.1 cc will be injected intradermally into each square using an insulin syringe. Treatment will be given every two weeks for a total of four sessions, followed by visits at 3 and 6 months after the last session.	Biological: Exosomes; Intradermal injection of 0.1 cc exosome product per 1 cm² square into the affected dermatome, every two weeks for four sessions.
Experimental: PRP; Participants will receive intradermal injections of autologous platelet-rich plasma into the affected dermatome. Ten mL of blood will be collected under aseptic conditions and centrifuged at 1000 rpm for 10 minutes. The lower 1-2 cc of plasma will be used as platelet-rich plasma concentrate. The affected dermatome will be marked into 1 cm² squares, and 0.1 cc PRP will be injected intradermally into each square. Treatment will be given every two weeks for four sessions, followed by visits at 3 and 6 months after the last session.	Biological: PRP; Autologous platelet-rich plasma prepared from 10 mL patient blood by centrifugation at 1000 rpm for 10 minutes, injected intradermally at 0.1 cc per 1 cm² square every two weeks for four sessions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in Pain Severity Using the Visual Analog Scale	Baseline and final treatment session, approximately 6 weeks after baseline

Secondary Outcome Measures

Outcome Measure	Time Frame
Change in Neuropathic Pain Scale Score	Baseline, final treatment session, 3 months after last session, and 6 months after last session

Collaborators and Investigators

• Sponsor: Zagazig University

Study record dates

Study Major Dates

• Study Start (Actual): February 2, 2025
• Primary Completion (Estimated): August 6, 2026
• Study Completion (Estimated): November 11, 2026

Study Registration Dates

• First Submitted: April 27, 2026
• First Submitted That Met QC Criteria: April 27, 2026
• First Posted (Actual): May 4, 2026

Study Record Updates

• Last Update Posted (Actual): May 4, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Nervous System Diseases; Neuromuscular Diseases; Peripheral Nervous System Diseases; Neuralgia; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Neuralgia, Postherpetic; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Adrenal Cortex Hormones
• Other Study ID Numbers: 984/5-1-2025

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No