572 Defining chronic wound types in recessive dystrophic epidermolysis bullosa patients for clinical outcome assessment

Abstract

The natural history of wounds in RDEB is not well defined. Serial photography and patient surveys were used to evaluate 213 wounds in 37 RDEB patients from EB Clinical Research Consortium and Stanford EB clinic. Mean size of chronic open wounds was 62 ± 55 cm2 with a mean duration of 5 ± 4 years. In contrast, recurrent wounds (mean size 51 ± 44 cm2) healed within 4 ± 3 weeks but re-blistered in 5 ± 6 weeks. The wound area was confirmed with photographs (N=17 wounds), where patients reliably self-reported wounds into two categories (0-39cm2 vs >40cm2), showing 92.3% agreement with investigator photographs, kappa 0.85. The distinct time course of chronic open wounds (N =7) and recurrent wounds (N =10) was also serially photographed for 8 months in 17 patients. Separate Fishers exact test analyses were performed for the two types of wounds. Larger chronic open wounds were on the trunk (p = 0.05) and more recurrent wounds were on the lower extremities (p = 0.035). Mean pain score was 4/10 ± 3) for both types; however, chronic open wounds had more frequent infections (p = 0.024). On multivariate analysis, including age and COL7A1 mutation, patients with premature termination codon mutations were 3-fold more likely to have larger chronic open wounds (OR 3.2, 95% CI, 1.5-7.0, P = 0.003). This study defines two types of chronic RDEB wounds: chronic open vs recurrent wounds. Patient self-report with a wound questionnaire correlated well with investigator measurements and when used in conjunction with serial photography, may improve clinical trial outcome assessment, and understanding of natural history of RDEB wounds.