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

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.