Psoriasis is an immune-mediated chronic inflammatory condition affecting the skin, joints, and other systems of the body. Plaque psoriasis is the most common type of psoriasis in which inflamed erythematous scaly patches of skin are formed that result in itching, redness and pain. It also often associated with a lower quality of life and can have psychosocial effects. Psoriasis patients are at higher risk of developing other chronic conditions such as cardiovascular disorders, Crohn disease, lymphoma, anxiety, and depression. Approximately 1 million Canadians are affected with psoriasis. The economic burden of moderate-to-severe plaque psoriasis has been estimated as $1.7 billion annually. The diagnosis of psoriasis is made based on clinical findings and the Psoriasis Area Severity Index (PASI) score is used to grade the severity of the disease based on induration, erythema, and scaling.