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

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: 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, 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: 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)

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): April 17, 2026
• Last Update Submitted That Met QC Criteria: April 15, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: corticosteroids; taste perception; pdt; 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