Impact of PDT and Topical Corticosteroids on Taste Perception in Patients With OLP

April 15, 2026 updated by: Magdalena Sulewska, Medical University of Bialystok

Impact of Photodynamic Therapy and Topical Corticosteroids on Taste Perception in Patients With Oral Lichen Planus

Oral lichen planus (OLP) is a chronic inflammatory disease that affects the lining of the mouth and may cause pain, burning sensations, and discomfort. Some patients also report changes in their ability to taste different flavors.

The aim of this study is to compare two commonly used treatments for OLP: photodynamic therapy (PDT) and topical corticosteroids. PDT is a light-based treatment that uses a special gel applied to the affected areas, followed by illumination with a medical light device. Topical corticosteroids are anti-inflammatory medications applied directly to the lesions.

Participants in this study are randomly assigned to receive one of these two treatments. Before starting therapy and immediately after its completion, patients undergo a simple taste test using special strips that assess the ability to recognize sweet, sour, salty, and bitter tastes. In addition, the size of oral lesions and the intensity of symptoms such as pain or burning are evaluated.

The results of this study may help to better understand how different treatments for oral lichen planus affect taste perception and overall patient well-being, and may support the selection of the most appropriate therapy in clinical practice.

Study Overview

Status

Status

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

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.

Detailed Description

Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa, frequently associated with pain, burning sensations, and impaired quality of life. Alterations in gustatory function have also been reported in patients with OLP; however, the impact of different therapeutic approaches on taste perception remains insufficiently investigated.

The aim of this randomized clinical trial is to evaluate and compare the effects of ALA (5-aminolevulonic acid) -based photodynamic therapy (PDT) and topical corticosteroid therapy (CT) on gustatory function in patients with clinically and histologically confirmed OLP.

Participants are randomly allocated to one of two parallel treatment groups: (1) ALA-PDT using a 5% 5-aminolevulinic acid mucoadhesive emulgel followed by irradiation with a 630 nm LED light source, administered in five weekly sessions; or (2) topical corticosteroid therapy with clobetasol propionate applied twice daily for two weeks.

Gustatory function is assessed using standardized taste strips, evaluating sweet(0-4), sour(0-4), salty(0-4), and bitter (0-4) taste perception, as well as total taste score (0-16), before treatment initiation and immediately after therapy completion. Secondary outcomes include changes in lesion size and subjective symptom severity assessed using the Visual Analog Scale (VAS) (0-10).

This study aims to provide evidence on the comparative effectiveness of PDT and topical corticosteroids in modulating taste perception and clinical outcomes in patients with OLP, thereby supporting evidence-based therapeutic decision-making.

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 (Actual)

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.
65

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 Locations

  • Poland
    • Podlaskie Voivodeship
      • Bialystok, Podlaskie Voivodeship, Poland, 15-089
        • Medical University of Bialystok

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:

  • age 18 years or older
  • clinically and histologically confirmed diagnosis of oral lichen planus

Exclusion Criteria:

  • pregnancy or lactation presence of systemic diseases, including dermatologic diseases, oncologic diseases, or severe liver disorders known allergies use of immunomodulatory or immunosuppressive drugs use of antidepressants use of bone anti-metabolites photosensitivity allergy to the components of the photosensitizer treatment for oral lichen planus within the previous 6 months inability to attend follow-up visits presence of oral lesions other than oral lichen planus

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: Single

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.
Experimental: Photodynamic therapy

Patients with clinically and histologically confirmed oral lichen planus receive photodynamic therapy using a proprietary 5% 5-aminolevulinic acid (ALA) mucoadhesive emulgel (patent P.443813, Poland). After drying the oral mucosa, a 2 mm layer of the ALA emulgel is applied to the lesion and surrounding tissue twice, 40 and 20 minutes prior to irradiation. The treated area is covered with an occlusive dressing secured with gauze.

Irradiation is performed using a FotoSan® 630 LED lamp (CMS Dental, Denmark) with a wavelength of 630 nm for 6 minutes per cm² of lesion area. The treatment consists of five sessions conducted at weekly intervals.

Gustatory function is assessed using standardized taste strips before the initiation of therapy and immediately after completion of the treatment.
Drug: 5-Amino Levulinic Acid
A 5% 5-aminolevulinic acid (ALA) mucoadhesive formulation is applied topically to oral lichen planus lesions. The preparation is administered twice (40 and 20 minutes prior to light irradiation) under occlusive conditions to enhance tissue penetration.
Active Comparator: Corticosteroid therapy

Patients with clinically and histologically confirmed oral lichen planus receive topical corticosteroid therapy with clobetasol propionate cream (0.5 mg/g; Bausch Health, Poland). The medication is applied directly to the lesions twice daily for a period of two weeks, in accordance with standard clinical practice.

Gustatory function is assessed using standardized taste strips before the initiation of therapy and immediately after completion of the treatment.
Drug: Clobetasol Propionate 0.05% Cream
Clobetasol propionate 0.05% (Clobederm) is applied topically to oral lichen planus lesions twice daily for a period of 5 weeks, according to standard clinical practice.

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
Measure Description
Time Frame
Change in taste function
Time Frame: Baseline (Day 1) and after treatment (Day 14 for CT group and Day 35 for PDT group)
Change in gustatory function assessed using Taste Strips, including identification of sweet, sour, salty, and bitter tastes, and total taste score.
Baseline (Day 1) and after treatment (Day 14 for CT group and Day 35 for PDT group)

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
Measure Description
Time Frame
Change in pain intensity (VAS)
Time Frame: Baseline (Day 1) and after treatment (Day 14 for CT group and Day 35 for PDT group)
Change in patient-reported pain intensity assessed using a 10-point (0-10) Visual Analog Scale (VAS) from baseline to post-treatment.
Baseline (Day 1) and after treatment (Day 14 for CT group and Day 35 for PDT group)
Change in lesion size
Time Frame: Baseline (Day 1) and after treatment (Day 14 for CT group and Day 35 for PDT group)
Change in oral lesion surface area (cm²) measured clinically between baseline and post-treatment.
Baseline (Day 1) and after treatment (Day 14 for CT group and Day 35 for PDT group)

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.
Medical University of Bialystok

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.
September 30, 2021

Primary Completion (Actual)

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.
January 10, 2023

Study Completion (Actual)

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.
July 10, 2023

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 7, 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 15, 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.
April 17, 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.
April 17, 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 15, 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

Keywords

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.
  • APK.002.372.2021

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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