I have had scalp psoriasis since I was a kid. My mom and my aunt have it all over their arms and legs. I thought I was lucky to have it only on my scalp (at least it's mostly hidden) but a couple years ago I got small patches on my knees, and a couple weeks ago on my elbows. I was just looking at the bumps and realized they looked really dry and scaly like psoriasis and looked up pictures on google and it looks exactly like it.