INTRODUCTION
Psoriasis is a chronic inflammatory skin disease that is characterized by disfiguring, scaling, and erythematous plaques that can be painful or severely pruritic.1 In the United States, an estimated 7.4 million adults are living with psoriasis.2 The severity of psoriasis is defined by both the extent of body surface area (BSA) affected and whether the lesions involve crucial body areas, such as the hands, feet, face, or genitals; however, there is no clear unifying definition of mild, moderate, or severe psoriasis.3 The American Academy of Dermatology has defined mild, moderate, and severe psoriasis as <5%, ≥5% to <10%, and ≥10% BSA involvement, respectively. In clinical trials, ≥10% BSA involvement is required for classification as moderate-to-severe psoriasis.3 Most patients seen in clinical practice have mild-to-moderate psoriasis (~80%), whereas moderate-to-severe disease affects about 20% of patients.3 Psoriasis is associated with significant morbidity and comorbidity, such as autoimmune diseases, cardiovascular disease, and metabolic syndrome, which, especially in severe disease, can increase mortality risk.1 Psoriasis can significantly affect the physical, social, and psychological well-being of the patient, leading to a deterioration in quality of life comparable to that noted with other severe chronic diseases, such as cancer.4Although the pathogenesis of psoriasis has not been fully elucidated, both genetic and environmental factors are now known to contribute to the development of the disease. Increased understanding of the mechanism of psoriasis has led to the development of a variety of new antipsoriatic therapies that target key steps in its pathogenesis.
Psoriasis Treatment Options and Goals
There is no cure for psoriasis at this time.5 The treatment goal remains to control clinical symptoms of the skin, reduce systemic disease potential, and to improve the patient’s quality of life.5 Topical medications are still the mainstay of therapy for the majority of patients when the disease is limited or mild.1,3 Among these medications, topical vitamin D analogs (eg, calcipotriene) and corticosteroids (eg, betamethasone), and these drugs in combination, are the most widely prescribed psoriasis drugs and are the cornerstone of topical therapies.6,7 Extensive treatment options, involving biologics, traditional systemic therapies, or phototherapy, are often reserved for patients with moderate-to-severe disease.1,3 Biologic agents have taken forefront in the treatment of moderate-to-severe psoriasis, in view of their favorable risk/benefit ratio; nevertheless,
