Psoriasis and Joint Pain. If you have psoriasis and have experienced pain, stiffness, or swelling in and around your joints, you may be experiencing symptoms of a psoriasis-related disease called psoriatic arthritis, or PsA. PsA is a chronic inflammatory disease that affects both your skin and your joints.
There are seven colors in the rainbow: red, orange, yellow, green, blue, indigo and violet. Roy G. Biv. Portrait of Sir Isaac Newton by Godfrey Kneller. Awesome rainbow hairstyling courtesy of Azael Carrera.
We can see millions of variations in color but we split up the rainbow into just six main colors when trying to describe what we see--red, orange, yellow, green, blue, purple. For the thousands of odors that we can smell we have barely any words at all, usually resorting to simile--smells like fresh cut grass, lemon, wet dog, stinky cheese.