Unmet Needs in the Field of Psoriasis: Pathogenesis and Treatment

In times of targeted therapies, innovative therapeutics become tools to further unravel the pathogenesis of the treated disease, thus influencing current pathogenetic concepts. Based on such paradigm shifts, the next generation of novel therapeutic targets might be identified. Psoriasis is a good example for the resulting most fruitful dialog between clinical and fundamental research. As a result of this, the key role of Th17 lymphocytes, some of their effector molecules, as well as mediators contributing to their maturation have been identified, many of these being targeted by some of the most effective drugs currently available to treat psoriasis. During this process, it became obvious that major parts of the puzzle remain yet to be uncovered or understood in much more detail. This review will therefore address the search for additional important effector cells other than Th17 lymphocytes, such as neutrophils, monocytes, and mast cells, mediators other than IL-17A, including some other IL-17 isoforms, and trigger factors such as potential autoantigens. This will lead to discussing the next generation of targeted therapies for psoriasis as well as treatment goals. These goals need to comprise both psoriasis as well as its comorbidities, as a comprehensive approach to manage the whole patient with all his health issues is urgently needed. Finally, given the substantial differences in resources available in different parts of the world, the global burden of psoriasis and options on how to care for patients outside developed countries will be assessed.