Psoriasis: How It Works, Explained Simply

Video Transcript

Psoriasis is a long-term condition in which the immune system speeds up the life cycle of skin cells. Normally, new skin cells form at the base of the epidermis and take about a month to travel up to the surface and shed away. In psoriasis, immune signals drive that process far faster, so new cells reach the surface in a matter of days. They arrive faster than the older cells can shed, so they pile up into a raised, thickened patch called a plaque. The surface of that plaque is covered in silvery-white scale, and the skin beneath is red and inflamed, with widened blood vessels. Plaques often appear on the elbows, knees, lower back and scalp, and they usually have clearly defined edges. There are several forms. Plaque psoriasis is the most common, but it can also appear as small drop-like spots, or in skin folds. Psoriasis can also affect the joints, causing pain and stiffness. If that happens, it is worth raising with your doctor. It is a long-term condition rather than an infection, so it is not contagious. Treatment aims to slow the overactive cell turnover and calm the inflammation. This video is for general education only. It is not medical advice. Ask your doctor what's right for you.