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

April 27, 2026 updated by: Mona El Radi Kamal Mohamed Emam, Zagazig University

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

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
45

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Egypt
    • Zagazig
      • Zagazig, Zagazig, Egypt, 44519

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Time Frame
Change in Pain Severity Using the Visual Analog Scale
Time Frame: Baseline and final treatment session, approximately 6 weeks after baseline
Baseline and final treatment session, approximately 6 weeks after baseline

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Time Frame
Change in Neuropathic Pain Scale Score
Time Frame: Baseline, final treatment session, 3 months after last session, and 6 months after last session
Baseline, final treatment session, 3 months after last session, and 6 months after last session

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Zagazig University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 2, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 6, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
November 11, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 27, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 27, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 4, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 4, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 27, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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