The UPDATE trial (UVB Phototherapy in Dermatology for ATopic Eczema): study protocol for a randomized controlled trial of narrowband UVB with optimal topical therapy versus optimal topical therapy in patients with atopic eczema

Background Narrowband ultraviolet B (NB-UVB) phototherapy is commonly prescribed for patients with moderate-to-severe atopic eczema (AE). The efficacy of NB-UVB, however, has not yet properly been established, as current evidence is of low certainty. Our aim is to assess the short-term and long-term (cost-)effectiveness and safety of NB-UVB in adult AE patients by performing a pragmatic, multicenter, prospective, randomized, open-label, blinded-endpoint (PROBE) trial. This protocol outlines its methodology. Methods A pragmatic, multicenter, PROBE trial will be performed with 1:1 randomization of 316 adult patients with moderate-to-severe AE who have inadequate disease control with topical therapy and who are eligible for optimal topical therapy (OTT) or NB-UVB in combination with OTT as a next step. Participants in the interventional arm will receive a minimum of 3 months of OTT combined with 8 to 16 weeks of NB-UVB. The control group receives 3 months of OTT. Following the interventional phase, follow-up will continue for 9 months. Physician-reported and patient-reported outcomes (according to the Harmonising Outcome Measures for Eczema (HOME) Core Outcome Set) and adverse events are assessed at 4 weeks, 3, 6, 9, and 12 months. Discussion The UPDATE trial aims to provide high-quality evidence regarding the (cost-)effectiveness and safety of NB-UVB phototherapy in moderate-to-severe AE patients. Challenges that are addressed in the protocol include the possible bias arising from applying open-label treatment and the necessity of introducing OTT into the study design to prevent a high dropout rate.