Clinical summary of patient including evolution of facial rash, clinical timeline, and pedigree. (A) Progressive improvement of facial erythema and papulopustular lesions observed over time before and after initiating topical ruxolitinib in a 10-year-old patient with STAT1 GOF syndrome. (B) Timeline summarizing the patient’s clinical and treatments course. Green: IV treatments; red: oral treatments; blue: topical treatments. (C) Pedigree illustrating the inheritance of the STAT1 variant c.974T>A (p.Met325Lys). The father (black square) is clinically and genetically affected, carrying the heterozygous variant and showing clinical features of CMC. The mother (white circle) is healthy and does not carry the variant. The daughter (black circle) is both clinically affected and heterozygous for the same STAT1 variant. EBV, Ebstein-Barr virus; DNT, double-negative T cells; INFa, INF α; IV, intravenous; SMX-TMX, sulfamethoxazole-trimethoprim; MRI/A, magnetic resonance imaging/angiography; US, ultrasound; CT, computed tomography; EGD, esophagogastroduodenoscopy.