A 70-year-old female with psoriasis presents with a four-month history of worsening arthralgia. She mentions she has pain and stiffness in her big toes and most of her fingers. On examination, a telescoping finger deformity is seen on her right second digit.
Approximately 25% of patients with psoriasis may develop psoriatic arthritis. The exact proportion is hard to know because up to one-third of patients remain undiagnosed. Arthritis is rarely the presenting symptom of psoriasis; it may take a decade or longer for symptoms to surface.