Psoriasis in Norway: A Prescription-based Registry Study of Incidence and Prevalence

Epidemiological data on psoriasis in Norway are limi-ted. The aim of this study was to provide objective na-tional data on the incidence and prevalence of psoria-sis. Patients registered in the Norwegian Prescription Database with a diagnostic code indicating psoriasis vulgaris on prescriptions were included. During the period 2004 to 2020, 272,725 patients received pres-cription for psoriasis vulgaris in Norway. During the period 2015 to 2020, 84,432 patients received pres-cription for psoriasis vulgaris for the first time. In 2020, 71,857 (97.7%) patients received topical, 7,197 (9.8%) conventional systemic and 2,886 (3.9%) bio-logical medication for psoriasis vulgaris. In the period 2015 to 2020, the point prevalence of psoriasis was 3.8-4.6% and the incidence was 0.29-0.25%. Nor-way is divided into 4 geographical health regions. A latitudinal difference was observed between the 4 re-gions, highest in Northern Norway. In the incidence population, median age was 47-53 years and males comprised 46-50%. In this study of psoriasis vulgaris, prevalence in Norway was higher than in earlier re-ports from other countries. There was a small female predominance regarding incidence and prevalence; however, men had more prescriptions for systemic tre-atment. Prescriptions for psoriasis vulgaris showed a stable level, with a trend of increasing use of biological medication during the study period.