Epidermolysis Bullosa Oropharyngeal Severity (EBOS) score: A multicenter development and reliability assessment

Background: Epidermolysis bullosa (EB) is a genetic mucocutaneous disorder characterized by blister formation upon mild trauma. All 4 EB types may show oropharyngeal lesions involving either hard or soft tissues. Currently, there are very few data on EB scoring that include the oropharyngeal cavity. Objectives: We sought to develop an oropharyngeal severity score that was objective, valid, reliable, reproducible, easy to perform, and appropriate for all EB types. Methods: In this study, oral medicine specialists developed a new score, the EB Oropharyngeal Severity (EBOS) score. 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 interobserver and intraobserver reliability were assessed. Results: The EBOS mean total score was 12.9 ± 10.9 (range: 0-34). Both interobserver and intraobserver reliability for total score on all patients with EB were considered excellent (intraclass correlation coefficient 0.94; 95% confidence interval 0.90-0.96 and intraclass correlation coefficient 0.90; 95% confidence interval 0.84-0.94, respectively). Even analyzing each single parameter of the disease activity and structural damage, a substantial to excellent correlation was found in the interobserver (except for 4 sites) and intraobserver 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. Limitations: The sample size was small and the number of EB subtypes was limited. Conclusions: The EBOS score seems to represent an instrument capable of truly quantifying the oropharyngeal severity in different types/subtypes of EB, demonstrating excellent interobserver and intraobserver reliability.