Experimental Pharmacological Management of Psoriasis.

Psoriasis is a chronic, relapsing, immune-mediated systemic disease. Its pathogenesis is complex and not fully understood yet. Genetic and epigenetic factors interact with molecular pathways involving TNF-α, IL-23/IL-17 axis, and peculiar cytokines, as IL-36 or phosphodiesterase 4. This review discusses the mechanisms involved in the development of the disease, as well as the therapeutic options proposed following the investigation of the inflammatory psoriatic pathways. We performed a comprehensive search using the words "psoriasis" and the newest molecules currently under investigation and approval. From these data, a new scenario in psoriasis is occurring to personalize the therapies - especially systemic ones and those using small molecules - and avoid topical and injectable drugs. We reported the newest therapeutic opportunities, including the inhibitors of Janus kinase/tyrosine kinase 2, phosphodiesterase-4 and IL-36 receptor. Today, more than 20 molecules are under investigation for the treatment of cutaneous psoriasis. Most of them are constituted by small molecules or biologic therapies. This underlines how psoriasis needs systemic therapies, due to its complex pathogenesis and multisystemic involvement.