context: In the 1960s and '70s, new info about how the immune system -- your body's defense against germs -- plays a role in psoriasis led to several new treatments. Drugs like corticosteroids, cyclosporine, and methotrexate became mainstays for managing the disease. For the next few decades, though, advances in treatment slowed down. Thanks to recent progress in research, that's ancient history. New biologic therapies work well to treat psoriasis, and other new treatments are close to FDA approval. Research in psoriasis doesn't always make headlines -- or win funding -- like discoveries in cancer or heart disease. And studies are hamstrung by the one-of-a-kind nature of your skin. Unlike many other diseases, experiments on mice or other animals aren't very helpful. In recent years, research into other autoimmune diseases brought new insights about the immune system. It turns out that some of the problems in those conditions are active in psoriasis, as well. The new info brought treatments that target specific areas of your immune system. Called biologics, these drugs launched a new era of psoriasis treatment. They're medicines made from substances found in living things. Doctors inject these lab-made proteins or antibodies into your skin or bloodstream. Once inside the body, the drug blocks part of your altered immune system that adds to psoriasis. In general, biologics work on psoriasis because they: Curb T cells (a form of white blood cell) Block a substance called tumor necrosis factor-alpha ( TNF-alpha), one of the main messenger chemicals in the immune system Stop a family of your immune system's chemical messengers called interleukins Bind to proteins that cause inflammation The patches and plaques of psoriasis come after an interaction between your skin cells and white blood cells. Biologics interfere with TNF-alpha or T cells, or they target interleukins. This short-circuits that unhealthy link. This will ease your inflammation. You'll have less growth of thick, scaly skin, too. Biologic medicines approved by the FDA to treat moderate to severe psoriasis include: Adalimumab ( Humira), a TNF-alpha-blocking antibody Adalimumab-adbm ( Cyltezo), a biosimilar to Humira Brodalumab ( Siliq), a human antibody against interleukins Certolizumab pegol ( Cimzia), a TNF-alpha blocker Etanercept ( Enbrel), a TNF-alpha blocker Etanercept-szzs ( Erelzi), a biosimilar like Enbrel Guselkumab ( Tremfya), an antibody against interleukins Infliximab ( Remicade), a TNF-alpha blocker Ixekizumab ( Taltz), an antibody that binds to inflammation-causing proteins/interleukins Risankizumab-rzaa ( SKYRIZI), an antibody against interleukins Secukinumab ( Cosentyx), a human antibody against interleukins Ustekinumab ( Stelara), a human antibody against interleukins Biologics are good at treating psoriasis. In clinical trials, each of the drugs lowered psoriasis activity by at least 75% in many people. There are some drawbacks, though. Biologics can be expensive. Though they're safe for most people, they could raise your chances of infection, cancer, and other complications. Your doctor will need to keep close tabs on you to make sure you stay healthy. Apremilast is a drug you take by mouth that's approved to treat psoriatic arthritis and plaque psoriasis in adults. It curbs phosphodiesterase-4 ( PDE-4), an enzyme that controls inflammation. Side effects include diarrhea, nausea, and headache. Some people in studies who took the drug lost weight. If you use the medicine, it's recommended that you check your weight regularly and watch out for signs of depression.