Impact of Photodynamic Therapy With Curcumin on Tissue Repair and Quality of Life in Patients With Epidermolysis Bullosa, and Identification of Salivary Biomarkers

Epidermolysis bullosa (EB) is a rare condition that causes extreme fragility of the skin and mucous membranes, leading to the formation of painful blisters. It can be hereditary (HEB) or autoimmune (AEB), and its diagnosis requires invasive procedures such as biopsies. Saliva emerges as a promising alternative for diagnosis and monitoring, as it is easy to collect and contains relevant biomarkers. The disease has no cure, and care focuses on improving the daily lives of those affected. Lesions in oral soft tissues are common and affect functions such as chewing and speech. Photodynamic therapy (PDT), especially with curcumin, has shown positive results in treating oral lesions in other conditions due to its antimicrobial and anti-inflammatory properties. However, it has not yet been specifically studied in people with EB. The primary objective of this study is to evaluate the efficacy of PDT with curcumin in repairing oral lesions in people with EB. Secondary objectives are to assess the impact of photodynamic therapy on the quality of life of people with EB and to identify potential salivary biomarkers and their correlation with the current gold-standard markers of EB. Participant selection and research will be carried out at the Reference Center for Neurodevelopment, Care and Rehabilitation of Children (NINAR), in São Luís, Maranhão, in July 2025. Children, adolescents and adults diagnosed with EB who feed orally, as well as people without EB, will be included in the study. A single calibrated evaluator will be responsible for administering the questionnaires, performing the clinical examination, collecting saliva, and carrying out PDT. Demographic and socioeconomic information will be collected from participants and guardians. Dietary intake will be assessed using a 77-item food frequency questionnaire (FFQ) validated by ELSA-BRASIL (Chor et al., 2013). The following clinical data will be collected: dental caries, using the ICDAS system [scores 0 (healthy tooth), 5 (visible dentinal cavity) and 6 (extensive cavity)] (Ismail et al., 2007); molar-incisor hypomineralization (MIH), using the SES-MIH index (Cabral et al., 2019); soft tissue lesions (ulcers, vesicles, bullae), coloration (whitish, yellowish, reddish, etc.) and location (lips, tongue, palate, buccal mucosa, gingiva, etc.). Unstimulated saliva will be collected from EB participants at the NINAR facility and from non-EB participants (control) at the Ana Lúcia Chaves Fecury Clinical School. Saliva samples will be obtained using a 1 mL syringe between 7:00 and 10:00 AM, stored in Eppendorf tubes under refrigeration and subsequently in an ultrafreeze unit (-80°C) at the University of Ceuma. PDT will be performed with 0.1% curcumin gel, applied to the oral mucosal lesions for 5 minutes, followed by irradiation with a blue LED (Radii-CAL CX, 440/480 nm) for one and a half minutes. The procedure will be repeated for three consecutive days. Pain intensity will be monitored before and for seven days after treatment using the Wong-Baker FACES Scale (0 to 5). To assess the impact of treatment on the quality of life of children, the short-form Parental-Caregiver Perceptions Questionnaire (P-CPQ) will be completed by their parents or guardians. For adolescents (aged 12 and above) and adults, the Oral Health Impact Profile-14 (OHIP-14) will be applied. Both questionnaires will be administered before the 1st, 2nd, and 3rd PDT sessions. The reparative efficacy of PDT on lesions will be measured through clinical evaluation. Biochemical analyses will be performed at the laboratories of the Federal University of Uberlândia (UFU), including: metabolite extraction, mass spectrometry (ESI-MS and HPLC-MS), spectroscopy (ATR-FTIR), chemometric analysis, and identification of salivary biomarkers with the aid of artificial intelligence algorithms. Data will be subjected to descriptive analysis of qualitative variables (absolute and relative frequency) and quantitative variables (mean, standard deviation, median, and interquartile range). Statistical tests will be applied for intragroup comparison regarding treatment reparative efficacy and quality of life impact (before and after treatment days) and between groups (with and without EB) regarding salivary biomarkers. Statistical analyses will be conducted at a 5% significance level. SPSS for Windows (Version 20.0; SPSS Inc., Chicago) will be used for data analysis.