Narrowband ultraviolet B phototherapy is associated with a reduction in topical corticosteroid and clinical improvement in atopic dermatitis: a historical inception cohort study

Abstract

Background: Despite decades of use, the magnitude of efficacy of narrowband ultraviolet B (NB-UVB) phototherapy for atopic dermatitis (AD) beyond industry-sponsored trials remains unclear. Aim: To evaluate the clinical efficacy of NB-UVB in AD under real-world conditions. Methods: We conducted a historical inception cohort study using automated recording of dispensed drugs to provide an objective treatment outcome in a large population catchment of 420 000 people over 15 years. We analysed clinical treatment outcomes, recorded multicentre and prospectively over 15 years, of a large AD treatment cohort (n = 844), along with the drugs dispensed to this cohort. Results: The majority (70%) of patients with AD received significantly fewer topical corticosteroids (TCS) during the 12-month window after finishing NB-UVB compared with the 12-month window before starting the treatment (median reduction from 37.5 to 19.7 g/month). The number of patients dispensed with oral corticosteroids and antihistamines also dropped significantly (from 20% to 10% and from 69% to 31%, respectively), while all AD-unrelated drugs dispensed remained unchanged. Clinically, NB-UVB treatment achieved a ‘clear’ or ‘almost clear’ status in 48.7% of patients, while 20.4% achieved ‘moderate clearance’. Treatment outcomes scores were validated by a strong correlation with reduction in AD-specific drug treatment. Conclusion: Our data confirm the significant efficacy of NB-UVB for AD under conditions of routine care.