• Erdheim-Chester disease (ECD) is associated with Langerhans cell histiocytosis (LCH) • Bone pain, xanthelasma, hairy kidney • Differential diagnoses of LCH • BRAF mutation associated with cardiac and neurological phenotype of ECD Haroche J, Papo M #EULAR2023 @RheumNow https://t.co/AzKJKp82nq