Dandruff and scalp psoriasis share some of the same symptoms, but they're not the same condition. An itchy scalp and flakes are common to both. But dandruff flakes are greasy and yellowish, while psoriasis looks powdery and has a silver shine. If you have the latter, your doctor may suggest a medicated shampoo or give you medicine to put on your scalp.
If you have psoriatic arthritis, moderate exercise might improve your range of motion, ease joint pain and stiffness, give you more endurance, and make you more flexible.