Generalized Pustular Psoriasis Triggered by Amoxicillin in Monozygotic Twins with Compound Heterozygous IL36RN Mutations: Comment on the Article by Navarini et al

International Consensus Definition and Diagnostic Criteria for Generalized Pustular Psoriasis From the International Psoriasis Council

Importance

Generalized pustular psoriasis (GPP) lacks internationally accepted definitions and diagnostic criteria, impeding timely diagnosis and treatment and hindering cross-regional clinical and epidemiological study comparisons.

Objective

To develop an international consensus definition and diagnostic criteria for GPP using the modified Delphi method.

Evidence Review

The rarity of GPP presents a challenge in acquiring comprehensive published clinical data necessary for developing standardized definition and criteria. Instead of relying on a literature search, 43 statements that comprehensively addressed the fundamental aspects of the definitions and diagnostic criteria for GPP were formulated based on expert reviews of 64 challenging GPP cases. These statements were presented to a panel of 33 global GPP experts for voting, discussion, and refinements in 2 virtual consensus meetings. Consensus during voting was defined as at least 80% agreement; the definition and diagnostic criteria were accepted by all panelists after voting and in-depth discussion.

Findings

In the first and second modified Delphi round, 30 (91%) and 25 (76%) experts participated. In the initial Delphi round, consensus was achieved for 53% of the statements, leading to the approval of 23 statements that were utilized to develop the proposed definitions and diagnostic criteria for GPP. During the second Delphi round, the final definition established was, "Generalized Pustular Psoriasis is a systemic inflammatory disease characterized by cutaneous erythema and macroscopically visible sterile pustules." It can occur with or without systemic symptoms, other psoriasis types, and laboratory abnormalities. GPP may manifest as an acute form with widespread pustules or a subacute variant with an annular phenotype. The identified essential criterion was, "Macroscopically visible sterile pustules on erythematous base and not restricted to the acral region or within psoriatic plaques."

Conclusions and Relevance

The achievement of international consensus on the definition and diagnostic criteria for GPP underscores the importance of collaboration, innovative methodology, and expert engagement to address rare diseases. Although further validation is needed, these criteria can serve as a reference point for clinicians, researchers, and patients, which may contribute to more accurate diagnosis and improved management of GPP.

Pustular psoriasis with a focus on generalized pustular psoriasis: classification and diagnostic criteria. An Italian expert consensus

Generalized pustular psoriasis (GPP) is a severe and life-threatening systemic disease associated with significant morbidity and mortality. Recent progress has been made in understanding the pathogenetic pathways involved in GPP and an intricate interaction between innate and adaptive immune mechanisms has been suggested. Despite formal consensus guidelines on pustular psoriasis currently available in the literature, the definitions and classifications of GPP used across studies were inconsistent. Consequently, there are no unified criteria that can be universally adopted for precise diagnosis, classification and effective treatment of GPP patients with new targeted drugs. The aim of this review was to collect all the main evidence on available diagnostic criteria for GPP and to establish recommendations in order to promote a better stratification and therapeutic management of this severe and heterogeneous disease.

Diverse Control Mechanisms of the Interleukin-1 Cytokine Family

The majority of interleukin-1 (IL-1) family cytokines lack amino terminal secretion signals or transmembrane domains for secretion along the conventional biosynthetic pathway. Yet, these factors must be translocated from the cytoplasm across the plasma membrane into the extracellular space in order to regulate inflammation. Recent work has identified an array of mechanisms by which IL-1 family cytokines can be released into the extracellular space, with supramolecular organizing centers known as inflammasomes serving as dominant drivers of this process. In this review, we discuss current knowledge of the mechanisms of IL-1 family cytokine synthesis, processing, and release from cells. Using this knowledge, we propose a model whereby host metabolic state dictates the route of IL-1β secretion, with implications for microbial infection and sterile inflammation.

A review of antibiotics and psoriasis: induction, exacerbation, and amelioration

Introduction: Psoriasis is affected by many environmental factors, including infections and antibiotics. However, the relationship between antibiotics and psoriasis is inadequately studied. Some antibiotics were listed as triggering factors; others showed benefit for psoriasis control. The aim of this article is to review current evidence that may help identify appropriate antibiotics for patients with psoriasis. Areas covered: The PubMed, Embase, Clinicalkey databases, and google scholar were searched for relevant articles published up to May 2019. Literature regarding antibiotics and psoriasis were included. Six randomized controlled trials and four controlled or cohort studies were identified in 13 kinds of antibiotics. Expert opinion: Macrolides and rifampin showed decrease of psoriasis area and severity index score in plaque-type psoriasis, while penicillin revealed no statistically significant improvement in guttate psoriasis. Previously tetracyclines were considered as triggering factors, but data were found only in cases or retrospective studies. Mechanisms were thought to be related to immunomodulation rather than bacteria inhibition. Research gap in the influence of genetic susceptibility, the impact on microbiota, and the mode of actions remain to be investigated.

Diagnosis and screening of patients with generalized pustular psoriasis

Generalized pustular psoriasis (GPP) is a rare and potentially life-threatening variant of psoriasis that is characterized by recurrent, acute onset, widely distributed pustular eruptions on inflamed, erythematous skin. It is important to recognize acute GPP as a subtype of psoriasis associated with high morbidity and mortality so therapy can be initiated without delay. Since GPP was first described in 1910 by Leopold von Zumbusch, it has been inconsistently defined, stratified, and diagnosed in the literature. Multiple definitions and diagnostic criteria have been proposed over the years. Recently, formal consensus guidelines on GPP have been published by international groups. This article reviews the current evidence and understanding in the diagnosis and screening of GPP.

Japanese guidelines for the management and treatment of generalized pustular psoriasis: The new pathogenesis and treatment of GPP

Generalized pustular psoriasis (GPP) is a rare disease characterized by recurrent fever and systemic flushing accompanied by extensive sterile pustules. The committee of the guidelines was founded as a collaborative project between the Japanese Dermatological Association and the Study Group for Rare Intractable Skin Diseases under the Ministry of Health, Labour, and Welfare Research Project on Overcoming Intractable Diseases. The aim of the guidelines was to provide current information to aid in the treatment of patients with GPP in Japan. Its contents include the diagnostic and severity classification criteria for GPP, its pathogenesis, and recommendations for the treatment of GPP. Since there are few clinical trial data with high levels of evidence for this rare disease, recommendations by the committee are described in the present guidelines.

Generalized pustular psoriasis in a 92-year-old man with a homozygous nonsense mutation in IL36RN

A 92-year-old man developed an erythematous eruption on the trunk and extremities with numerous pustules accompanied by fever. He had never experienced pustular eruption or been diagnosed with psoriasis previously. Skin biopsy revealed Kogoj's spongiform pustule, and he was diagnosed with generalized pustular psoriasis (GPP). Genomic DNA was extracted from his peripheral blood and the sequence of IL36RN gene was analyzed, which revealed a p.Arg10X homozygous mutation. Several cases of elderly-onset GPP have been reported, however, this is the oldest case of GPP. The existence of splice variants of IL36RN was suspected, but we could not detect any splice variants of IL36RN in this case or in a healthy control from peripheral blood samples.