Since I was on dermatology last week, this will be skin week.
A patient presents to your clinic complaining of morning stiffness of the hands lasting over half an hour. His joints also hurt, but the stiffness and pain improve with use. On physical exam, you note some joint line tenderness and effusions, mostly involving the distal interphalangeal joints. The image is shown above. He has some pitting edema of the extremities. He was also treated last week for uveitis. Note the nail involvement; below is a textbook example of mild (left) to severe (right) nail findings.
Challenge: What's your diagnosis?
First image is in the public domain. Second image is shown under fair use.