Long-Term Efficacy of 5-ALA Photodynamic Therapy in Oral Lichen Planus Patients

Background: Oral lichen planus (OLP) is a chronic mucosal disease associated with a risk of malignant transformation. Although topical corticosteroids are the standard therapy, prolonged administration may result in local and systemic complications. Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) has been proposed as a less invasive and safer alternative. Methods: In this prospective study, 44 patients with histologically verified OLP underwent a protocol consisting of ten consecutive weekly PDT sessions, each comprising a single irradiation. A 5% ALA formulation was topically applied, followed by illumination with a 630 nm red light device. Clinical outcomes were evaluated at baseline, immediately after therapy, and at 12- and 48-month follow-ups. Changes in lesion surface, REU index, and pain intensity on a visual analog scale (VAS) were analyzed. Results: Significant improvements were noted, with progressive and sustained decreases in lesion extent, REU scores, and VAS values throughout the 4-year observation period. The therapeutic response was consistent across different mucosal sites (keratinized and non-keratinized). No treatment-related adverse reactions were recorded. Conclusions: Long-term follow-up indicates that ALA-mediated PDT is a safe and effective management option for both reticular and erosive variants of OLP. Its durable clinical benefits and favorable safety profile support its role as an alternative to corticosteroid therapy.