Options and opportunities for clinical management and treatment of psoriasis. 
Psoriasis is a complex, multifactorial disease that appears to be influenced by immune-mediated components.  For many years the pathogenesis of psoriasis has been discordant; the clinical picture suggested that the psoriasis was secondary to abnormal keratinocyte proliferation and differentiation, but later the role of the T cell was revealed.  A variety of treatment options range from topical agents (e.g., coal tar, dithranol, and emollients for milder forms) to systemic agents (i.e., methotrexate or cyclosporin), and phototherapy.  Recently, biologics have been added to this list that target particular steps in the immune or inflammatory pathways.  Various nanocarriers (e.g., liposomes, niosomes, and microemulsions) have been successfully exploited for the delivery of several antipsoriatic drugs.  This review provides insight into various psoriasis treatment strategies-from conventional to novel-currently in use or in development as well as the novel targets that have been explored and/or investigated for anti-psoriatic therapy.  The pathogenesis of psoriasis and some of the topical, systemic biological, and novel approaches currently in use or in development are reviewed here.  The pros and cons of each treatment strategy are presented, as are some of the animal models used to study features reminiscent of psoriasis.  This information can be used to better the understanding of treatment options for this disease.