Clinical Features and Outcomes of Children's Interstitial Lung Disease Accompanied with Connective Tissue Disease: A Prospective Cohort Study.

•It is a prospective cohort study on childhood interstitial lung disease (chILD) with connective tissue disease (CTD), expounding careful phenotyping and outcomes assessments of a rare but potentially fatal disease.•Higher lung imaging score, cyanosis, progression to rapidly progressive ILD, acute respiratory distress syndrome, CD4 T cell <200, may predict poor outcome in CTD-chILD.•Care providers should conduct an assessment for CTD in chILD as a longer interval between the diagnosis of chILD and the CTD is associated with increased mortality.