Arthritis mutilans in a patient with juvenile idiopathic arthritis.

A 60-year-old woman had been diagnosed with juvenile idiopathic arthritis at 14 years of age and treated with multiple disease-modifying antirheumatic drugs without any proven efficacy. She subsequently underwent bilateral total hip and knee arthroplasty in her forties, and treatment with infliximab and etanercept had been discontinued due to the onset of pneumocystis pneumonia and bacterial pneumonia, respectively. Accordingly, she had been treated with prednisolone alone for the past three years. Serological tests revealed a rheumatoid factor level of 640 IU/mL (normal <20) and anti-cyclic citrullinated peptide antibody titer of 304 U/ mL (normal <4.5). A recent hand radiograph showed bilateral marked dislocation with a pencil-in-cup deformity of the metacarpophalangeal and proximal interphalangeal joints and shortening of the metacarpals, suggesting arthritis mutilans (Picture). Arthritis mutilans is the most severe form of arthropathy associated with psoriatic arthritis and rheumatoid arthritis, characterized by shortening of the digits to create the so-called “opera-glass hand.”