A 35-year-old woman presents with a worsening skin rash over the past year. The rash started on her elbows and knees but has since spread to her scalp and lower back. It is intensely pruritic and often bleeds with scratching. She reports that new spots have appeared after minor scrapes. She has recently noticed worsening stiffness and pain in her fingers, especially in the morning. The rash makes her feel self-conscious, causing her to avoid social events and wear long-sleeved clothing even in warm weather. Her mother has a similar skin condition. She is a smoker and drinks alcohol socially. She is not on any medications, over-the-counter drugs, or supplements.