Generalized pustular psoriasis-Dawn of a new era in targeted immunotherapy

Generalized pustular psoriasis (GPP) is a rare, inflammatory skin disease characterized by recurrent flares of pustulation accompanied by systemic symptoms. Due to its acuteness, sufficient diagnosis and treatment are essential, but often face challenges. We recently overviewed various treatment options of GPP utilizing established therapies in psoriasis vulgaris (PsO). Although there is a pathogenic relation to PsO, more and more evidence suggests a predominant involvement of the innate immune system in GPP. Recent discoveries on the genetic background of GPP with underlying mutations in IL36RN, CARD14, AP1S3 and SERPINA3 contributed to a better understanding of the pathogenesis and provide major opportunities in the development of innovative, targeted therapies. The proposed umbrella term "autoinflammatory keratinization diseases" (AIKD) helps to categorize this heterogeneous disease. Finally, we address the problem of insufficient standardized assessment tools and propose a reproducible scoring system also capturing the systemic features of GPP. In summary, GPP is a prototype disease to demonstrate both obstacles and progress in dermatology-currently insufficient definition and diagnostic tools on the one hand side, yet major advances in dissecting disease heterogeneity, opportunities for novel diagnostic techniques and therapeutic decision-making based on molecular events on the other side.