IntroductionSarcoidosis is an idiopathic systemic granulomatosis whose evolution is self-limiting in the majority of cases. However, it can progress to organ damage that menaces the vital or functional prognosis of patients. Sarcoidosis itself, but also its comorbidities, can pose a threat to the patient, require rapid initiation of treatment and justify emergency hospitalization. Research questionWhat are the reasons and prognosis of sarcoidosis patients hospitalized in emergency ? MethodsThe objectives of our study were to describe the causes of admission, and to identify predictors of mortality in sarcoidosis patients hospitalized in emergency. This is a retrospective monocentric study. We included patients hospitalized after a stay in the emergency room or in intensive care unit (ICU) or requiring an unscheduled hospitalization after a telephone advice or a consultation, between 01/01/2017 and 07/07/2020. ResultsWe identified 154 sarcoidosis patients hospitalized in emergency, among which 14 (9%) required the ICU. There were 81 men, with a median age of 55.0 [44.0; 67.0] years. Sarcoidosis was inaugural in 20 (14%) patients. The primary reason for hospitalization was lower respiratory infections in 32 (21%) patients, followed by acute pulmonary exacerbation of sarcoidosis in 17 (11%), suspected cardiac sarcoidosis in 13 (8.4%), and neurosarcoidosis in 12 (7.7%). The median length of stay was 6 [3.00; 10.0] days. In-hospital mortality rate was 3.9%. The 2-year transplantation-free survival following hospitalization was 86,8% [95% CI 81,4- 92,5]. The factors associated with a worse transplantation-free survival were Charlson comorbidity index (HR=1.29 [95% CI=1.04-1.61]; p=0.021), pulmonary hypertension (HR=2.53 [95% CI=1.10-5.83]; p=0.029), and oxygen therapy during hospitalization (HR=4.18 [95%CI=1.55-11.29]; p=0.005). InterpretationThe overall mortality of sarcoidosis patients hospitalized in emergency is high. The presence of comorbidities and the severity of respiratory failure, as reflected by oxygen requirement, are important prognostic determinants.