Failure to thrive, interstitial lung disease, and progressive digital necrosis with onset in infancy.

Key teaching points • SAVI is a recently described interferonopathy resulting from constitutive action of STING and up-regulation of IFN-β signaling. • SAVI is characterized by facial erythema with telangiectasia, acral/cold-sensitive tissue ulceration and amputations, and interstitial lung disease. It has overlapping features with Aicardi-Goutières syndrome and familial chilblain lupus. • Traditional immunosuppressive medications and biologic therapies appear to be of limited benefit, but JAK inhibitors may impact disease progression.