Psoriasis is an autoimmune condition that causes excessive growth of the skin cells. It is the most common of all autoimmune diseases, affecting millions of Americans. Psoriasis outbreaks tend to be triggered by stress or cold weather, though they can also result from sunburns, infections, or even cigarette smoking. Flare-ups usually mean red scales, dried and cracked skin, or itchy, scaly, pink skin. Usually it affects the elbows or knees, but psoriasis can happen anywhere there is skin. On the scalp, psoriasis is a common cause of dandruff. Psoriasis can also turn the fingernails yellow, and many patients report joint pain as well.
Psoriasis should be distinguished from eczema. Both are characterized by itchy, scaly skin, but the two are different conditions. Psoriasis is an autoimmune disorder, caused by the body’s immune system treating the patient’s own skin as foreign tissue and attacking it. Eczema can be an allergic reaction which is similar to autoimmunity in that the immune system kicks into gear against something harmless, but in the case of eczema, that harmless thing is legitimately foreign matter. Nonetheless, it can be difficult for dermatologists to determine which of the diseases a particular patient has—it might even be both. Scientists have recently developed a genetic test to help doctors tell the diseases apart. This is an important step because the different causes mean different treatments are needed for anything more than short-term symptom relief.
One new treatment for psoriasis involves a protein in the skin that, when stimulated, has been found to prevent the inflammation associated with the disease under laboratory condition. Researchers suggest that, even if this treatment alone is not entirely effective, it can be used in combination with medication to enhance its effectiveness and show results sooner.
Another treatment uses a medication called secukinumab that is already used for other autoimmune diseases. This medication reduces the action of a type of immune cell that is also involved in asthma and rheumatoid arthritis. In tests, it was shown to be more effective than the current treatments, which are anti-inflammatory drugs to address that aspect and vitamin D to help heal the skin.