Background: Narrowband ultraviolet B phototherapy (nbUVB) is an established treatment modality for patients with severe atopic dermatitis (AD) and is known to increase serum vitamin D levels (SVD). The relationship between SVD and AD remains unclear.
Objectives: To assess SVD and disease severity in patients with AD before and after nbUVB and establish whether a change in SVD correlates to response to nbUVB. Methods: A single-centre, open observational study recruited 21 male and 17 female patients with AD between November and April. Eczema severity was measured using the SCORAD tool, and serum 25-hydroxyvitamin D3 levels were determined before and after nbUVB, which was administered thrice weekly.
Results: Nine patients had severe AD, 23 moderate and six mild, as indicated by SCORAD measurements. Seventeen patients completed the study. Median SVD increased from 45 nmol/l pre-treatment to 169 nmol/l post-treatment (95% CI 2.9–5.0 times baseline) (P < 0.0001). Mean SCORAD reduction following nbUVB was significant at 21.9 units (95% CI, 14.9–28.9) (P < 0.0001). No evidence of a relationship between change in SCORAD and change in SVD was found.
Limitations: A significant number of patients failed to complete the study.
Conclusions: Patients with AD are at risk of vitamin D deficiency. Correlation between this and disease severity has been postulated, but this study does not provide confirmatory evidence.