Psoriasis is characterized by scaly plaques that can appear on any part of the body, especially the elbows, knees and lower back. Psoriasis can run in families and may also cause joint pain, nail problems and severe dandruff- like rashes on the scalp. There are many treatments available for psoriasis and there has recently been a very important breakthrough in psoriasis treatment that appears to be very effective and safe. These new medications are called "biologics" because they work by interacting with specific responses of your immune system. If you have psoriasis, see your dermatologist to discuss the best treatment for you.