Image of the Week: Painful urination, a swollen knee, and eye pain

A 31-year-old woman presents to the emergency department with a 2-day history of pain on urination and discomfort in her left knee and heel. She also complains of right eye pain, which is exacerbated by reading and bright lights. She recently recovered from a gastrointestinal illness 2 weeks earlier but is otherwise healthy. Examination reveals a swollen left knee that ...