TY - JOUR T1 - Is it Useful to Calculate Minimal Erythema Dose Before Narrowband UV-B Phototherapy? JO - Actas Dermo-Sifiliográficas T2 - AU - Rodríguez-Granados,M.T. AU - Estany-Gestal,A. AU - Pousa-Martínez,M. AU - Labandeira,J. AU - Gato Otero,R. AU - Fernández-Redondo,V. SN - 15782190 M3 - 10.1016/j.adengl.2017.08.019 DO - 10.1016/j.adengl.2017.08.019 UR - https://actasdermo.org/en-is-it-useful-calculate-minimal-articulo-S1578219017302780 AB - Introduction and objectivesThe starting dose for narrowband UV-B phototherapy is determined by a patient's skin phototype or minimal erythema dose (MED). Calculation of MED identifies patients with unsuspected photosensitivity. The aim of this study was to investigate the influence of factors such as concomitant use of photosensitizing agents, diagnosis, and combination with acitretin in patients with psoriasis on the frequency and severity of adverse effects in patients with a low MED to narrowband UV-B phototherapy. Material and methodsWe undertook a retrospective observational cohort study between February 1, 2009 and March 31, 2015. MED values were classified as normal or low. ResultsIn total, 302 patients with different skin conditions started narrowband UV-B phototherapy at a dose determined by their MED. No differences were found between patients with a low MED and those with a normal MED for number of drugs taken (P=.071) or use of photosensitizing agents (P=0.806). Following adjustment for age, sex, and phototype, the multivariate analysis showed that psoriasis exerted a protective effect against a low MED (OR=0.31 [95% CI, 0.16-0.58]). No significant risk of erythema or pruritus was detected in patients with a low MED (OR=1.68; 95% CI, 0.91-3.29 and OR=2.04; 95% CI, 0.99-4.22, respectively). ConclusionsPsoriasis protects against a low MED. Although erythema and pruritus were more common in patients with a low MED, the differences were not significant. ER -