IntroductionPityriasis lichenoides (PL) is a papulosquamous disease affecting both children and adults, for which narrowband-UVB (NB-UVB) phototherapy is regarded as a commonly used treatment option. The aim of this study was to investigate the efficacy of NB-UVB phototherapy in the management of PL and to compare response rates in pediatric and adult age groups. Materials and methodsThis observational, retrospective study included 20 PL patients (12 pityriasis lichenoides chronica; PLC, 8 pityriasis lichenoides et varioliformis acuta; PLEVA) who failed to respond to other treatment modalities. The data for this study were collected retrospectively from patient follow-up forms in the phototherapy unit. ResultsA complete response (CR) was obtained in all pediatric patients with PL, while 53.8% of adult patients had achieved CR. The mean cumulative dose required to achieve the CR was higher in pediatric patients than adult patients with PL (p < .05). The CR was achieved in 6 (75%) of 8 PLEVA patients, while 8 (66.7%) of 12 PLC patients had reached to CR. The mean number of exposures for patients with PLC to achieve a CR was higher than patients with PLEVA (p < .05). Erythema was the most common adverse effect during phototherapy particularly in 5 (35.7%) of the patients with PL who had achieved CR. ConclusionsNB-UVB is an effective and well-tolerated treatment option for PL especially in diffuse types. A higher response can be obtained in children with higher cumulative dose. Patients with PLC may require more exposures for CR than patients with PLEVA.