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

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.

We sought to develop an oropharyngeal severity score that was objective, valid, reliable, reproducible, easy to perform, and appropriate for all EB types.

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.

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.

The sample size was small and the number of EB subtypes was limited.

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.