Variable vessel vasculitis of arteries and veins in VEXAS syndrome

A man in his 50s receiving immunomodulatory therapy for presumed Behçet's disease presented with odynophagia and jaw pain. Three months earlier, he had developed deep vein thrombosis and extensive superficial phlebitis with transmural inflammation on histopathology. Imaging revealed carotid artery vasculitis and unilateral inflammation around the temporal vessels. Ultrasound demonstrated wall thickening of the right temporal vein with normal temporal arteries. Persistent systemic inflammation and bicytopenia prompted bone marrow examination revealing myelodysplastic syndrome. Detection of a somatic UBA1 mutation confirmed VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic). Glucocorticoids and interleukin-1 blockade were initiated. Due to severe cytopenia, the patient underwent allogeneic haematopoietic stem cell transplantation, resulting in clinical remission. VEXAS causes variable vessel vasculitis, affecting arteries and veins alike even without thrombosis. In older men with myelodysplasia or cytopenia, VEXAS should be considered in the differential of both venous and arterial vasculitis. Ultrasound may distinguish temporal phlebitis from giant cell arteritis.