Psoriasis is an immune-mediated skin disorder characterized by raised, red and scaly patches on the skin that multiplies 10 times faster than normal. Psoriasis commonly affects the knees, elbows and/or scalp but can occur anywhere on the body, and may cause itching, burning or stinging. There are different types, with the most common being plaque psoriasis, and between 10-30% of individuals with psoriasis also have psoriatic arthritis. Although the exact cause of psoriasis is unknown, it can be strongly linked to the immune system and genetics. Topical treatments can help treat mild to moderate cases, and are used in combination with medications or light therapy for more severe cases.