Psoriasis is a chronic, immune-mediated disease with a complex pathogenetic process triggered by a combination of genetic and environmental factors that induce secretion of tumour necrosis factor (TNF) α by keratinocytes, which in turn activates dendritic cells. There are various limitations associated with existing therapies, although new understanding of the pathogenesis of psoriasis has led to the development of novel targeted therapeutics. Interleukin inhibitors represent a major therapeutic advance, as they appear to be highly selective in terms of mitigating the perturbed inflammatory pathways responsible for psoriasis.
IL-1 and IL-36 are the highly expressed dominant cytokines in generalised pustular psoriasis. In comparison, the expression of IL-17 and IL-22 is reduced. 
Anakinra is a synthetic, injectable, IL-1 receptor antagonist that has led to exciting results in pustular psoriasis in patients with no response to anti-TNF agents.
Inhibition of the IL-36 pathway has also been recently examined in pustular psoriasis. 
In particular, a phase I proof-of-concept study has been performed in 7 patients who presented with a generalised pustular psoriasis flare and treated with a single, open-label, intravenous dose of BI 655130, a monoclonal antibody against the IL-36 receptor. 
Pustules were completely cleared in three patients within 48 hours after treatment, in 5 patients by week 1 and in 6 patients by week 2.
The results were maintained until at least 20 weeks when the study ended.
Thus, blockade of both the IL-1 and IL-36 pathways is associated with extremely good clinical response, consistent with the observed overexpression of the two cytokines.
Gilliet M, Conrad C, Geiges M, et al. Psoriasis triggered by toll-like receptor 7 agonist imiquimod in the presence of dermal plasmacytoid dendritic cell precursors. Arch Dermatol. 2004 Dec;140(12):1490-5.
Presenter disclosure information: M Gilliet: Abbvie, Amgen, Celgen, Galderma, Genentech, La Roche-Posay, Lilly, Novartis, Roche.
Presented by: Prof. Kristian Reich, Translational Research in Inflammatory Skin Diseases, Institute for Health Services Research in Dermatology and Nursing, University Medical Center Hamburg-Eppendorf, and Skinflammation® Center, Hamburg, Germany