Itch in recessive dystrophic epidermolysis bullosa: findings of PEBLES, a prospective register study

Background Itch is common and distressing in epidermolysis bullosa (EB) but has not previously been studied in depth in different recessive dystrophic EB (RDEB) subtypes. Objectives As part of a prospective register study of the natural history of RDEB we explored features of itch, medications used, and correlation with disease severity and quality of life. Methods Fifty individuals with RDEB aged 8 years and above completed the Leuven Itch Scale (LIS) (total 243 reviews over a 7-year period). Data included itch frequency, severity, duration, distress, circumstances, consequences, itch surface area and medications for itch. The iscorEB disease severity score and the validated EB quality of life tool, QOLEB, were compared to LIS domains and analysed by RDEB subtype. Results Itch was frequent, present in the preceding month in 93% of reviews. Itch severity and distress were significantly greater in severe (RDEB-S) and pruriginosa (RDEB-Pru) subtypes compared to intermediate RDEB (RDEB-I). Itch medications were reported in just over half of reviews including emollients, topical corticosteroids and antihistamines; the proportion of participants not using medication despite frequent pruritus suggests limited efficacy. In inversa RDEB (RDEB-Inv) and RDEB-I, LIS domains correlated with iscorEB and QOLEB. In contrast to previous studies, correlations were lacking in RDEB-S suggesting that global disease burden relatively reduces the contribution of itch. Conclusions This comprehensive study of RDEB-associated itch highlights differences between RDEB subtypes, suggests an unmet need for effective treatments and could serve as control data for future clinical trials incorporating itch as an endpoint.