Baricitinib experience on STING-associated vasculopathy with onset in infancy: A representative case from Turkey.

Stimulator of interferon genes associated vasculopathy with onset in infancy (SAVI), caused by heterozygote gain-of-function mutations in TMEM173, is characterized by fever attacks with ulcerating cutaneous manifestations on cold-sensitive areas and interstitial lung disease. A six-month-old boy was admitted to our hospital with fever, cough, and rash on the external surface of both upper and lower extremities. Respiratory symptoms consistent with ILD developed and skin lesions evolved to eschar formation particularly on acral regions. Ultimately, diagnosis of SAVI was confirmed at the age of 10 months due to the high level of interferon-score and a heterozygous N154S mutation in TMEM173. Since systemic corticosteroid and ruxolitinib were not effective, baricitinib was initiated at the age of 15 months, resulting in alleviation of fever attacks, cutaneous manifestations and respiratory symptoms within 2 months. In conclusion, we reported an infant diagnosed with SAVI at the age of 10 months and treated with baricitinib.