Current management of generalized pustular psoriasis

Generalized pustular psoriasis (GPP) is a rare subset of psoriasis involving episodes of sterile pustules accompanied by inflammation and, often, systemic involvement. The inflammatory nature of GPP has potential for severe multisystem complications including high-output cardiac failure, infections, digestive system issues, and disfiguring or lethal acute flare episodes. The disease tends to have higher prevalence in females and Asians. The IL-1/IL-36 inflammatory pathway is a critical facet of GPP's pathology. Genetic mutations that are associated with GPP include modifications of Interleukin 36 Receptor Antagonist (IL36RN), Caspase Recruitment Domain Family Member 14 (CARD14), Adaptor Related Protein Complex 1 Subunit Sigma 3 (AP1S3), Myeloperoxidase (MPO) and Serpin Peptidase Inhibitor Clade A Member 3 (SERPINA3) genes. Treatment guidelines for GPP are not well-entrenched. Currently, only one GPP-specific treatment, the interleukin-36 receptor antagonist (IL-36Ra) spesolimab, has been approved for use in the United States. Additional anti-IL-36 pathway therapies are currently being developed. Other treatment options include other biologic therapies such as IL-17 inhibitors, IL-23 inhibitors and TNFα inhibitors. Non-biologic therapeutic options include retinoids, cyclosporine and methotrexate. Treatment options differ throughout the world; most countries utilize retinoids, cyclosporine and methotrexate as first-line non-biologic options. China and United Kingdom have no GPP-specific biologic therapies approved for use, while several biologic therapies are approved for use in Japan. This review aims to serve as an update on the current global management of GPP while also including relevant aspects of disease pathogenesis, diagnosis, clinical presentation, histopathology, aetiology and epidemiology.

Generalized Pustular Psoriasis: Divergence of Innate and Adaptive Immunity

Generalized pustular psoriasis (GPP) is a severe, relapsing, immune-mediated disease characterized by the presence of multiple sterile pustules all over the body. The exact pathomechanisms behind GPP remain elusive, although increased interest in the genetic basis and immunological disturbances have provided some revealing insights into the underlying signaling pathways and their mutual interaction. The genetic background of GPP has been thoroughly investigated over the past few years. The conducted studies have identified genetic variants that predispose to pustular forms of psoriasis. The loss-of-function mutation of the interleukin 36 receptor antagonist gene, along with rare gain-of-function mutations in the gene that encodes the keratinocyte signaling molecule (CARD14), are examples of the uncovered abnormalities. Interleukin 36 (IL-36), along with neutrophils, is now considered a central cytokine in GPP pathogenesis, with IL-36 signaling providing a link between innate and adaptive immune responses. More recently, a new concept of inflammation, caused by a predominantly genetically determined abnormal activation of innate immune response and leading to inflammatory keratinization, has arisen. GPP is currently considered a representative of this novel group of skin conditions, called autoinflammatory keratinization diseases. As no therapeutic agents have been approved for GPP to date in the United States and Europe, the novel anti-IL-36R antibodies are particularly promising and may revolutionize management of the disease.

A brief guide to pustular psoriasis for primary care providers

Pustular psoriasis refers to a heterogeneous group of chronic inflammatory skin disorders that are clinically, histologically, and genetically distinct from plaque psoriasis. Pustular psoriasis may present as a recurrent systemic illness (generalized pustular psoriasis [GPP]), or as localized disease affecting the palms and/or soles (palmoplantar pustulosis [PPP], also known as palmoplantar pustular psoriasis), or the digits/nail beds (acrodermatitis continua of Hallopeau [ACH]). These conditions are rare, but their possible severity and consequences should not be underestimated. GPP, especially an acute episode (flare), may be a medical emergency, with potentially life-threatening complications. PPP and ACH are often debilitating conditions. PPP is associated with impaired health-related quality of life and psychiatric morbidity, while ACH threatens irreversible nail and/or bone damage. These conditions can be difficult to diagnose; thus, primary care providers should not hesitate to contact a dermatologist for advice and/or patient referral. The role of corticosteroids in triggering and leading to flares of GPP should also be noted, and physicians should avoid the use of systemic corticosteroids in the management of any form of psoriasis.

An update on generalized pustular psoriasis

Introduction: Generalized pustular psoriasis (GPP) is a rare, severe relapsing/remitting, multisystem disease that can be difficult to treat. Recent clinical, histological, and genetic evidence suggests that GPP is a distinct clinical entity from plaque psoriasis and requires a separate diagnosis. The interleukin-36 pathway appears to be central to GPP pathogenesis. As no therapeutic agents have been approved for GPP to date in the United States or Europe, the introduction of anti-IL-36 therapies may change disease management. Areas covered: Using PubMed and Google Scholar, we reviewed the literature for articles related to GPP, psoriasis, and the genetics, pathogenesis, and treatment thereof. Expert opinion: New therapeutic options and updated guidelines for GPP treatment are needed. Ideal agents would have rapid onset of action and rapid time to achieve disease clearance, have the ability to prevent acute flares and avert recurrence, and possess a favorable safety profile. Such therapies should be readily accessible via approval or listing on formularies. Scoring systems to establish GPP disease burden and objective outcome measures could also help with further evaluation of therapies and treatment access issues. IL-36 remains a promising target, as supported by early phase data suggesting efficacy and safety for a novel anti-IL-36 therapy.

Pustular psoriasis: pathophysiology and current treatment perspectives

Psoriasis vulgaris is a chronic inflammatory disease that classically affects skin and joints and is associated with numerous comorbidities. There are several clinical subtypes of psoriasis including the uncommon pustular variants, which are subdivided into generalized and localized forms. Generalized forms of pustular psoriasis include acute generalized pustular psoriasis, pustular psoriasis of pregnancy, and infantile and juvenile pustular psoriasis. Localized forms include acrodermatitis continua of Hallopeau and palmoplantar pustular psoriasis. These subtypes vary in their presentations, but all have similar histopathologic characteristics. The immunopathogenesis of each entity remains to be fully elucidated and some debate exists as to whether these inflammatory pustular dermatoses should be classified as entities distinct from psoriasis vulgaris. Due to the rarity of these conditions and the questionable link to the common, plaque-type psoriasis, numerous therapies have shown variable results and most entities remain difficult to treat. With increasing knowledge of the pathogenesis of these variants of pustular psoriasis, the development and use of biologic and other immunomodulatory therapies holds promise for the future of successfully treating pustular variants of psoriasis.