Psoriasis is a chronic autoimmune skin condition characterized by the rapid growth of skin cells, leading to the formation of red, scaly patches that can be itchy and painful. It commonly affects areas like the elbows, knees, scalp, and lower back, but can appear anywhere on the body. The exact cause is not fully understood, but it involves a combination of genetic, immune, and environmental factors. Treatments aim to reduce inflammation and slow down cell turnover, including topical therapies, phototherapy, and systemic medications.