Impact of PDT and Topical Corticosteroids on Taste Perception and Salivary Oxidative Stress Markers in Patients With OLP

Oral lichen planus (OLP) is a long-term inflammatory disease affecting the lining of the mouth. It may cause pain, burning sensations, discomfort, and changes in the appearance of the oral mucosa. Some patients may also notice changes in their ability to recognize different tastes.

The aim of this study is to compare two treatments used for OLP: photodynamic therapy (PDT) and topical corticosteroid therapy. PDT is a light-based treatment in which a special gel containing 5-aminolevulinic acid is applied to the affected areas and then activated using a medical light device. Topical corticosteroids are anti-inflammatory medicines applied directly to the oral lesions.

Participants are randomly assigned to receive one of these two treatments. Their ability to recognize sweet, sour, salty, and bitter tastes is assessed using special taste strips before treatment and immediately after therapy is completed. The size of the oral lesions and the severity of symptoms, such as pain and burning, are also evaluated.

Saliva samples are collected before treatment, immediately after treatment, and 3, 6, and 12 months after therapy. These samples are used to measure cortisol and several substances related to inflammation and cellular stress, including malondialdehyde, advanced oxidation protein products, peroxynitrite, nitrotyrosine, and advanced glycation end products.

The results may help researchers better understand how photodynamic therapy and topical corticosteroids affect taste perception, oral symptoms, lesion healing, and biological changes in the saliva of patients with OLP. The findings may also support the selection of the most appropriate treatment in clinical practice.

Study Overview

• Status: Completed
• Conditions: Oral Lichen Planus
• Intervention / Treatment: Drug: 5-Amino Levulinic Acid; Drug: Clobetasol Propionate 0.05% Cream

Detailed Description

Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa that is 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 effects of different therapeutic approaches on taste perception and salivary biomarkers of oxidative, nitrosative, and carbonyl stress remain insufficiently investigated.

The aim of this randomized clinical trial is to evaluate and compare the effects of 5-aminolevulinic acid-based photodynamic therapy (ALA-PDT) and topical corticosteroid therapy (CT) on gustatory function, clinical outcomes, and selected salivary biomarkers 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, sour, salty, and bitter taste perception, with scores ranging from 0 to 4 for each taste modality and a total taste score ranging from 0 to 16. Taste perception is evaluated before treatment initiation and immediately after completion of therapy.

Salivary concentrations of cortisol, malondialdehyde (MDA), advanced oxidation protein products (AOPP), peroxynitrite, nitrotyrosine (NT), and advanced glycation end products (AGEs) are assessed before treatment, immediately after therapy completion, and at 3, 6, and 12 months following each therapeutic intervention. These measurements are intended to evaluate longitudinal changes in psychological stress and oxidative, nitrosative, and carbonyl stress associated with OLP and its treatment.

Additional clinical outcomes include changes in lesion size and subjective symptom severity assessed using a 10-point Visual Analog Scale (VAS).

This study aims to provide evidence on the comparative effectiveness of ALA-PDT and topical corticosteroid therapy in modulating taste perception, clinical manifestations, and salivary stress-related biomarkers in patients with OLP. The findings may contribute to a better understanding of the biological effects of both therapeutic approaches and support evidence-based treatment decision-making.

• Study Type: Interventional
• Enrollment (Actual): 65
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Change in taste function	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

Outcome Measure	Measure Description	Time Frame
Change in pain intensity (VAS)	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	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)
Change in salivary biomarkers of stress and oxidative, nitrosative, and carbonyl damage	Salivary concentrations of cortisol, malondialdehyde (MDA), advanced oxidation protein products (AOPP), peroxynitrite, nitrotyrosine (NT), and advanced glycation end products (AGEs) will be measured to assess changes in stress-related responses and oxidative, nitrosative, and carbonyl damage associated with oral lichen planus and its treatment.	Measurements will be performed before treatment, immediately after therapy completion, and at 3, 6, and 12 months after treatment.

Collaborators and Investigators

• Sponsor: Medical University of Bialystok

Study record dates

Study Major Dates

• Study Start (Actual): September 30, 2021
• Primary Completion (Actual): January 10, 2023
• Study Completion (Actual): July 10, 2023

Study Registration Dates

• First Submitted: April 7, 2026
• First Submitted That Met QC Criteria: April 15, 2026
• First Posted (Actual): April 17, 2026

Study Record Updates

• Last Update Posted (Actual): July 14, 2026
• Last Update Submitted That Met QC Criteria: July 13, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: oxidative stress; corticosteroids; taste perception; pdt; carbonyl stress; nitrosative stress; olp
• Additional Relevant MeSH Terms: Mouth Diseases; Stomatognathic Diseases; Lichenoid Eruptions; Skin Diseases, Papulosquamous; Skin Diseases; Skin and Connective Tissue Diseases; Lichen Planus; Lichen Planus, Oral; Amino Acids, Peptides, and Proteins; Organic Chemicals; Carboxylic Acids; Polycyclic Compounds; Amino Acids; Steroids; Fused-Ring Compounds; Steroids, Fluorinated; Betamethasone; Keto Acids; Levulinic Acids; Aminolevulinic Acid; Clobetasol
• Other Study ID 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