Common symptoms of psoriasis include thick, red or purple patches of skin covered with silvery-white scales that can be itchy or painful. These patches often appear on the elbows, knees, scalp, and lower back. Other symptoms may include dry, cracked skin that may bleed, itching or burning sensations, thickened or pitted nails, and swollen or stiff joints. The severity and appearance of symptoms can vary widely among individuals.