RT Journal Article SR Electronic T1 Sarcoidosis in Iceland: a nationwide study of epidemiology, clinical picture and environmental exposure JF ERJ Open Research JO erjor FD European Respiratory Society SP 00550-2021 DO 10.1183/23120541.00550-2021 VO 7 IS 4 A1 Sigríður Ólína Haraldsdóttir A1 Jon Gunnlaugur Jonasson A1 Kristin Bara Jorundsdottir A1 Haraldur Jon Hannesson A1 Thorarinn Gislason A1 Bjorn Gudbjornsson YR 2021 UL http://openres.ersjournals.com/content/7/4/00550-2021.abstract AB Background This nationwide study aimed to elucidate the incidence and clinical characteristics of tissue-verified sarcoidosis in Iceland. A secondary aim was to analyse sex differences and identify possible environmental factors contributing to the pathological process.Materials and methods This is a descriptive study covering 36 years (January 1, 1981 through December 31, 2016). Histopathological reports and electronic hospital discharge registries were reviewed in context for granulomas and/or sarcoidosis. National data were used for comparison regarding smoking habits and occupation, adjusted for age, sex and year of diagnosis. The data were stored in FileMaker and calculations were made by extracting data from this database to the statistical software package R.Results A total of 418 patients (54% females) were diagnosed with tissue-verified sarcoidosis. The incidence rate was 4.15/100 000/year, similar among females and males. The mean age at diagnosis was higher among females (53.0±14.2 years) than males (48.2±13.8 years). Fatigue was the most frequent single symptom (49.7%), but when all respiratory symptoms were grouped, they were the most frequent symptoms (60%). No significant difference was found between smoking status and sarcoidosis. Possible hazardous exposure in the workplace was reported by 19.4% of the cases.Conclusion The incidence of sarcoidosis in Iceland was higher than in an Asian population where the same inclusion criteria were applied. The clinical picture diverges partly from that in the Asian population but resembles that among other Caucasians. Fatigue and respiratory symptoms were predominant. The biphasic pattern of age at disease debut seen elsewhere among females was not evident in Iceland.This paper describes a nationwide study on the incidence of tissue-verified sarcoidosis in Iceland, focusing on clinical symptoms, smoking and occupation. The incidence is low, and main symptoms are fatigue and symptoms of the respiratory tract. https://bit.ly/3ur6jk8