RT Journal Article SR Electronic T1 Erosive rheumatoid arthritis in a young patient with mirror hand JF BMJ Case Reports JO BMJ Case Reports FD BMJ Publishing Group Ltd SP bcr-2018-227739 DO 10.1136/bcr-2018-227739 VO 12 IS 2 A1 Ali Sibtain Farooq Sheikh A1 Ernest Wong YR 2019 UL http://casereports.bmj.com/content/12/2/bcr-2018-227739.abstract AB Mirror hand is a congenital anomaly characterised by duplication of the ulnar ray, resulting in polydactyly and functional disability of the hand. It can cause arthralgias and weakness in intrinsic muscles of the hand. We present a young woman who had a surgically corrected mirror hand and subsequently developed aggressive rheumatoid arthritis, which increased her limitations to a significant degree. Early diagnosis and treatment in such cases is very important to prevent long-term disability.