16th August 2023

A 26-year-old patient presents with a 3-month history of lower back pain that improves with exercise and worsens with rest

A 26-year-old patient presents with a 3-month history of lower back pain that improves with exercise and worsens with rest. On examination, he is found to have decreased lumbar spinal movement. He also reports a family history of psoriasis.

What other clinical feature, if present, would increase the likelihood of ankylosing spondylitis?