PHOTODYNAMIC THERAPY AS SUPPORT OF PHARMACOLOGICAL THERAPY IN A CASE OF PARTICULAR REFRACTORY ORAL LICHEN PLANUS: A CASE REPORT.

Aim: Lichen planus (LP) is a chronic autoimmune mucocutaneous condition, primarily affecting the oral and genital mucous membrane, skin, nails, and scalp. The oral lichen planus (OLP) affects approximately 2% of the population. OLP, in general, may arise in > 70% of persons with skin lesions. The frequency of malignant change ranges from 0.4% to 3.3%. OLP is seen worldwide, mostly in the fifth to sixth decades of life, and is twice as prevalent in women as in men. OLP has demonstrated numerous systemic connotations such as diabetes mellitus (DM), hypertension, metabolic syndrome (MS), thyroid diseases, psychosomatic ailments, chronic liver disease, gastrointestinal diseases, and genetic susceptibility to cancer. The treatment options for OLP are numerous and include topical and systemic agents. Topical corticosteroids remain the mainstay of therapy. Case report: A 62-year-old woman came to our observation for a lesion present for about 1 year extended to the hard palate and the upper vestibular gingival mucosa. In the anamnesis she reported osteoporosis and gastro-esophageal reflux. On objective examination there were erosion areas of different width and depth interspersed with erythematous and rare areas white patterns. The patient also reported the formation of bubbles that in a very short time exploded. The negative Nickolsky sign on physical examination did not testify for a diagnosis of vesicular-bullous disease. An incisional biopsy was performed in the palatine area. The subsequent histological evaluation and immunofluorescence were significant for the diagnosis of lichen planus bullous. Topical therapy prescribed with Clobetasol 0.05% 2 times a day and topical Nystatin (100.000 ul/ ml) 3-4 times a day for 3 weeks brought an evident improvement; however an erosive lesion persisted in the area 22-23. It was decided to proceed with a photodynamic support therapy with 460 nm diode light, 4 watts (FlashMax P4 CSM Dental, Copenhagen, Denmark) and 3% hydrogen peroxide. Mucous surface was wetted with hydrogen peroxide then illuminated with diode light 20 times for 3 seconds, subsequently the hydrogen peroxide was removed with a sterile gauze. This treatment was repeated 3 times every 7 days. Results: One week later there was an important clinical improvement, the subsequent therapeutic sessions allowed an almost complete remission of the lesion unresponsive to corticosteroid treatment. Numerous invasive and non- invasive therapeutic methods including local and systemic corticosteroids, laser therapy, and surgical intervention for the treatment of OLP are suggested. Extended use of corticosteroids for chronic OLP may have certain local and systemic complications, which includes opportunistic candidiasis, mucosal atrophy, adrenal insufficiency, gastrointestinal disorders, hypertension, and diabetes. To surmount the side effects of steroid therapy, photodynamic therapy (PDT) has been proposed as an alternative treatment strategy for OLP. PDT uses a photosensitizing agent which, when activated by the energy of light, creates a photodynamic reaction that is cytotoxic. A systematic review of the literature assessed the effectiveness of PDT in the management of OLP. PDT also showed an increase in the bactericidal activity of hydrogen peroxide in a case of refractory hairy tongue. Conclusions: Photodynamic therapy appears to have some effect in the symptomatic treatment of OLP in adult patients. However, further randomized controlled trials with standardized PDT parameters are needed.