History A 28-year-old woman presented to the emergency department with painful swelling of the third finger on her right hand, which developed quickly. She had no relevant medical or surgical history. Her pain was worse at night, with stiffness decreasing during the morning. Clinical examination revealed generalized swelling of the third finger, cyanotic skin, and fingernail splitting on the second finger of the left hand ( Fig 1 ). Laboratory test results were normal, with no evidence of inflammatory disease. Radiographs of both hands were obtained. CT scanning and MRI were also performed. Figure 1: Photograph of both of the patient's hands shows generalized swelling of the third digit of the right hand, corresponding to dactylitis (arrow). Also note the nail striations in the second digit of the left hand (∗).