A 42-year-old White woman presents to her primary care physician for her annual checkup. She reports stiffness, fatigue, and joint pain in her hands, fingers, wrists, right hip, and knee. She reports that her stiffness is worst in the morning and lasts for at least the first half hour of the day but improves steadily with movement. She also reports that she is "clumsy" with her hands, often dropping things and unable to maintain a secure grip. These symptoms have impaired her overall quality of life and have set limitations on her daily function. She is often late for work and has trouble completing the tasks of the day. She has a history of moderate to severe psoriasis with periods of remission, which was first diagnosed at age 28 years.

Physical exam reveals nail malformations in most of the nails on both hands that include pitting of the nail plate, transverse depressions, and subungual hyperkeratosis. There is distal interphalangeal joint swelling as well as the appearance of sausage digits on several fingers of each hand. On closer exam, scaly erythematous plaques (psoriasis) are visible on her scalp as well as around the umbilicus.

Laboratory testing reveals elevated erythrocyte sedimentation rate > 15 mm/h; C-reactive protein values are within the normal range. The patient is negative for rheumatoid factor titer and antinuclear antibody.