Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome in a patient with subacute cutaneous lupus (SCLE).

A man in his 60s suffered from refractory, biopsy-proven subacute cutaneous lupus erythematosus that required chronic, moderate dose steroids to manage. His rash was accompanied by arthralgias and negative autoantibody testing. His subacute lupus erythematosus (SCLE) was responsive to tofacitinib, but thrombotic complications limited the use of this medication. He continued prednisone 20 mg daily to manage his symptoms until treatment with anifrolumab completely cleared his skin. During a subsequent prednisone taper, he developed a macrocytic anaemia and elevated liver function tests that continued to progress. Ultimately, a bone marrow biopsy and myeloid next-generation sequencing revealed cellular vacuoles and UBA1 gene mutation, respectively, consistent with a diagnosis of VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. We believe the chronic steroid use to control his SCLE masked the underlying diagnosis for many years.