251 Natural history of wounds in patients with recessive dystrophic epidermolysis bullosa

Abstract

Recessive dystrophic epidermolysis bullosa (RDEB) patients suffer from recalcitrant, painful blistering and open wounds, however, a systematic natural history of RDEB wounds with patient reported outcomes such as pain and itch has not been conducted. We hypothesized that RDEB patients have 2 major types of wounds, chronic wounds, defined as those that stay open for ≥ 12 weeks, and recurrent wounds, which heal but reblister easily, and that these wounds differ in size, pain, and itch. Recruited from Stanford's EB clinic, 40 patients completed a questionnaire to evaluate the size, duration, and associated symptoms of chronic and recurrent wounds. To validate the accuracy of patients’ self-assessment, we also serially photographed, classified, and measured target wounds on 25 patients. In comparison, patients' self-assessments of wound type and size were moderately reliable (chronic/recurrent: 0.54, 95% CI 0.30-0.77; size: 0.52, 95% CI 0.27-0.70). Based on photographs taken over a mean of 37 weeks (2 – 153), we classified 24% of wounds as chronic and 76% as recurrent. Patients’ survey results indicated that 100% of patients’ recurrent wounds routinely close and reopen, closing within an average of 7 weeks and opening within an average of 5 weeks. Both survey results (N=40 patients) and photographs (N=25 patients) confirmed that chronic wounds were significantly larger than recurrent wounds (66.3 vs. 44.7 cm2, p=0.005). Chronic wounds were more painful than recurrent wounds (4.31 vs. 3.59, 0-10 Wong Baker FACES™ Pain Rating Scale, p=0.05). Chronic wounds were also itchier than recurrent ones (2.36 vs. 1.65, 0-4 Itch Man Scale, p=0.11). Within each wound type, larger size correlated with more pain and itch. These results confirm that there are 2 types of RDEB wounds with different size, pain, and itch traits, and that patients reliably assess wound type and size. Results from this natural history study further demonstrate that chronic and recurrent RDEB wounds have distinct clinical outcomes and clinical trial endpoints.