Accurate estimation of the incidence and prevalence of each subtype of epidermolysis bullosa (EB) is essential before clinical trials can be designed and sufficient funding allocated by government agencies and third-party insurers for the care of these individuals.
To determine the incidence and prevalence of inherited EB stratified by subtype in the United States during a 16-year period.
Design, Setting, and Participants
Prospective cross-sectional and longitudinal study. Data were obtained from 3271 patients consecutively enrolled in the National Epidermolysis Bullosa Registry from January 1, 1986, through December 31, 2002, using a detailed instrument created with the assistance of the National Institutes of Health. Analyses were performed in January 1999 and April 2015. Participants were patients of all ages with EB.
Main Outcomes and Measures
Extensive clinical and laboratory data were collected on patients who were subclassified and serially revalidated based on published diagnostic recommendations by an international panel of experts. Pertinent to this report, estimates were made of the incidence and prevalence during 2 time frames.
During the first 5 years of funding of the registry, the overall incidence and prevalence of inherited EB were 19.60 and 8.22 per 1 million live births, respectively. When reassessed over the entire 16 years of the study, the prevalence rose to 11.07, whereas the overall incidence remained unchanged at 19.57 cases. Changes were also observed within some disease subsets as increased numbers of patients were identified, recruited, followed up longitudinally, and resubclassified as needed over time. For example, in 2002, the prevalence of EBS overall and localized EBS had increased considerably by 30.4% and 25.5%, respectively, whereas the prevalence of generalized intermediate EBS declined by 76.7% as a result of later subclassification of some of those patients into other subtypes. In contrast, no significant change was noted in the overall prevalence of JEB or generalized severe JEB, although there was a 73.0% decline in the prevalence of generalized intermediate JEB.
Conclusions and Relevance
Precise estimates of the incidence and prevalence of each major subtype of inherited EB in the United States are now available that should assist investigators in choosing which subtypes are amenable to properly designed, large-scale, clinical trials.