EPIDERMOLYSIS BULLOSA OROPHARYNGEAL SEVERITY SCORE (EBOS): A MULTICENTRIC DEVELOPMENT AND RELIABILITY ASSESSMENT

Background: Epidermolysis bullosa (EB) is a rare genetic disorder characterized by constant formation of mucocutaneous blisters upon trivial trauma. All four EB types may show oropharyngeal lesions involving either hard or soft tissues. Currently, there are very few data on EB scoring including the oropharyngeal cavity. Objectives: To set up an oropharyngeal severity score that was objective, valid, reliable, reproducible, easy to perform, and appropriate for all EB types. Methods: In this multicentric study, oral medicine specialists developed a new score, the Epidermolysis Bullosa Oropharyngeal Score (EBOS). This measured oropharyngeal disease activity (erythema, atrophy, blisters, erosion/ulceration) and structural damage (microstomia, ankyloglossia, scarring phenotype beyond microstomia and ankyloglossia, enamel hypoplasia). It was tested on 92 patients with different types/subtypes of EB, and inter- and intra-observer reliability were assessed. Results: The EBOS mean total score was 12.9±10.9 (range 0†"33.5). Both inter-and intra-observer reliability for total score on all EB patients were considered excellent (ICC: 0.94; 95% confidence interval (CI): 0.90†"0.96 and ICC: 0.90; 95%CI: 0.84†"0.94, respectively). Even analyzing each single parameter of the disease activity and structural damage, a substantial-excellent correlation was found in the inter-observer (except for four sites) and intra-observer reliability. A significant correlation was found between EB types/subtypes and the EBOS median score (p< .001), but not between age and the EBOS mean total score in each group. Conclusions: The EBOS score seems to represent an instrument capable to truly quantify the oropharyngeal severity in different types/subtypes of EB, demonstrating an excellent inter- and intra-observer reliability.