Definition, acronyms, nomenclature, and classification of angioedema (DANCE): AAAAI, ACAAI, ACARE, and APAAACI DANCE consensus.

BACKGROUND: Angioedema (AE) manifests with intermittent, localized, self-limiting swelling of the subcutaneous and/or submucosal tissue. AE is heterogeneous, can be hereditary or acquired, may occur only once or be recurrent, may exhibit wheals or not, and may be due to mast cell mediators, bradykinin, or other mechanisms. Several different taxonomic systems are currently used, making it difficult to compare the results of studies, develop multicenter collaboration, and harmonize AE treatment. OBJECTIVE: We developed a consensus on the definition, acronyms, nomenclature, and classification of AE (DANCE). METHODS: The initiative involved 91 experts from 35 countries and was endorsed by 53 scientific and medical societies, and patient organizations. A consensus was reached by online discussion and voting using the Delphi process over a period of 16 months (June 2021 to November 2022). RESULTS: The DANCE initiative resulted in an international consensus on the definition, classification, and terminology of AE. The new consensus classification features 5 types and endotypes of AE and a harmonized vocabulary of abbreviations/acronyms. CONCLUSION: The DANCE classification complements current clinical guidelines and expert consensus recommendations on the diagnostic assessment and treatment of AE. DANCE does not replace current clinical guidelines, and expert consensus algorithms and should not be misconstrued in a way that affects reimbursement of medicines prescribed by physicians using sound clinical judgment. We anticipate that this new AE taxonomy and nomenclature will harmonize and facilitate AE research and clinical studies, thereby improving patient care.

Translation of cytoplasmic UBA1 contributes to VEXAS syndrome pathogenesis.

Somatic mutations in UBA1 cause vacuoles, E1 ubiquitin-activating enzyme, X-linked, autoinflammatory somatic (VEXAS) syndrome, an adult-onset inflammatory disease with an overlap of hematologic manifestations. VEXAS syndrome is characterized by a high mortality rate and significant clinical heterogeneity. We sought to determine independent predictors of survival in VEXAS and to understand the mechanistic basis for these factors. We analyzed 83 patients with somatic pathogenic variants in UBA1 at p.Met41 (p.Met41Leu/Thr/Val), the start codon for translation of the cytoplasmic isoform of UBA1 (UBA1b). Patients with the p.Met41Val genotype were most likely to have an undifferentiated inflammatory syndrome. Multivariate analysis showed ear chondritis was associated with increased survival, whereas transfusion dependence and the p.Met41Val variant were independently associated with decreased survival. Using in vitro models and patient-derived cells, we demonstrate that p.Met41Val variant supports less UBA1b translation than either p.Met41Leu or p.Met41Thr, providing a molecular rationale for decreased survival. In addition, we show that these 3 canonical VEXAS variants produce more UBA1b than any of the 6 other possible single-nucleotide variants within this codon. Finally, we report a patient, clinically diagnosed with VEXAS syndrome, with 2 novel mutations in UBA1 occurring in cis on the same allele. One mutation (c.121 A>T; p.Met41Leu) caused severely reduced translation of UBA1b in a reporter assay, but coexpression with the second mutation (c.119 G>C; p.Gly40Ala) rescued UBA1b levels to those of canonical mutations. We conclude that regulation of residual UBA1b translation is fundamental to the pathogenesis of VEXAS syndrome and contributes to disease prognosis.

Disease modification in chronic spontaneous urticaria.

Chronic spontaneous urticaria (CSU) is a debilitating, inflammatory skin condition characterized by infiltrating immune cells. Available treatments are limited to improving the signs and symptoms. There is an unmet need to develop therapies that target disease-driving pathways upstream of mast cell activation to inhibit or delay the progression of CSU and associated comorbidities. Here, we aim to define disease modification due to a treatment intervention and criteria that disease-modifying treatments (DMTs) must meet in CSU. We have defined disease modification in CSU as a favorable treatment-induced change in the underlying pathophysiology and, therefore, the disease course, which is clinically beneficial and enduring. A DMT must fulfil the following criteria: (1) prevents or delays the progression of CSU, (2) induces long-term, therapy-free clinical remission, which is the sustained absence of CSU signs and symptoms without the need for treatment, and (3) affects the underlying mechanism of CSU, as demonstrated by an effect on disease-driving signals and/or a biomarker. DMTs in CSU should slow disease progression, achieve long-lasting disease remission, target disease-driving mechanisms, reduce mast cell-activating IgE autoantibodies, target cytokine profile polarization, and normalize the gut microbiome and barrier. Treating CSU at the immune system level could provide valuable alternatives to pharmacotherapy in CSU management. Specific DMTs in CSU are yet to be developed, but some show potential benefits, such as inhibitors of Bruton's Tyrosine Kinase, IL-4 and IL-13. Future therapies could prevent CSU signs and symptoms, achieve long-term clinical benefits after discontinuing treatment, and prevent associated concomitant disorders.

Urticaria exacerbations and adverse reactions in patients with chronic urticaria receiving COVID-19 vaccination: Results of the UCARE COVAC-CU study.

BACKGROUND: Concern about disease exacerbations and fear of reactions after coronavirus disease 2019 (COVID-19) vaccinations are common in chronic urticaria (CU) patients and may lead to vaccine hesitancy. OBJECTIVE: We assessed the frequency and risk factors of CU exacerbation and adverse reactions in CU patients after COVID-19 vaccination. METHODS: COVAC-CU is an international multicenter study of Urticaria Centers of Reference and Excellence (UCAREs) that retrospectively evaluated the effects of COVID-19 vaccination in CU patients aged ≥18 years and vaccinated with ≥1 dose of any COVID-19 vaccine. We evaluated CU exacerbations and severe allergic reactions as well as other adverse events associated with COVID-19 vaccinations and their association with various CU parameters. RESULTS: Across 2769 COVID-19-vaccinated CU patients, most (90%) received at least 2 COVID-19 vaccine doses, and most patients received CU treatment and had well-controlled disease. The rate of COVID-19 vaccination-induced CU exacerbation was 9%. Of 223 patients with CU exacerbation after the first dose, 53.4% experienced recurrence of CU exacerbation after the second dose. CU exacerbation most often started <48 hours after vaccination (59.2%), lasted for a few weeks or less (70%), and was treated mainly with antihistamines (70.3%). Factors that increased the risk for COVID-19 vaccination-induced CU exacerbation included female sex, disease duration shorter than 24 months, having chronic spontaneous versus inducible urticaria, receipt of adenovirus viral vector vaccine, having nonsteroidal anti-inflammatory drug/aspirin intolerance, and having concerns about getting vaccinated; receiving omalizumab treatment and Latino/Hispanic ethnicity lowered the risk. First-dose vaccine-related adverse effects, most commonly local reactions, fever, fatigue, and muscle pain, were reported by 43.5% of CU patients. Seven patients reported severe allergic reactions. CONCLUSIONS: COVID-19 vaccination leads to disease exacerbation in only a small number of CU patients and is generally well tolerated.

Chronic Spontaneous Urticaria: A Review.

Importance: Chronic spontaneous urticaria affects approximately 1% of the general population worldwide, including approximately 3 million people in the US, impairs patients' quality of life, and is associated with multiple comorbidities. Observations: Chronic spontaneous urticaria affects patients of any age but is most common in females aged 30 to 50 years. Diagnosis is based on clinical presentation, ie, spontaneously recurring wheals, angioedema, or both. Chronic spontaneous urticaria persists for more than 1 year in most patients (1 or repeated episodes) and may present with comorbidities including chronic inducible urticaria (>10%), autoimmune thyroiditis (approximately 20%), metabolic syndrome (6%-20%), and anxiety (10%-31%) and depression (7%-29%). Known autoimmune endotypes (subtypes of urticaria defined by distinct pathogenesis) of chronic spontaneous urticaria are mediated by mast cell-activating IgE and/or IgG autoantibodies (>50%). Approximately 40% of patients with chronic spontaneous urticaria have a Dermatology Life Quality Index of more than 10, corresponding to a very large or extremely large negative effect on quality of life. Second-generation H1 antihistamines are first-line treatment; partial or complete response, defined as a reduction in urticaria symptoms of greater than 50%, is observed in approximately 40% of patients. The 2022 international urticaria guideline recommends the monoclonal anti-IgE antibody omalizumab as second-line treatment for antihistamine-refractory chronic spontaneous urticaria. However, at least 30% of patients have an insufficient response to omalizumab, especially those with IgG-mediated autoimmune urticaria. Cyclosporine, used off-label, can improve symptoms in approximately 54% to 73% of patients, especially those with autoimmune chronic spontaneous urticaria and nonresponse to omalizumab, but has adverse effects such as kidney dysfunction and hypertension. Conclusions and Relevance: Chronic spontaneous urticaria is an inflammatory skin disease associated with medical and psychiatric comorbidities and impaired quality of life. Second-generation H1 antihistamines are first-line treatment, omalizumab is second-line treatment, and cyclosporine is third-line treatment for chronic spontaneous urticaria.

Safety and efficacy of lirentelimab in patients with refractory indolent systemic mastocytosis: a first-in-human clinical trial.

BACKGROUND: Indolent systemic mastocytosis (ISM) is characterized by excessive mast cell (MC) accumulation and MC-driven signs and symptoms. Currently used therapies are not approved and have limited efficacy. Lirentelimab (AK002) is a monoclonal antibody against sialic acid-binding immunoglobulin-like lectin (Siglec)-8 that inhibits MC activation. OBJECTIVES: To determine the safety, tolerability and efficacy of lirentelimab in reducing the symptoms of ISM. METHODS: At a specialty centre for mastocytosis in Germany, we conducted a phase I first-in-human single-ascending and multidose clinical trial of lirentelimab in patients with ISM. Eligible adults had World Health Organization-confirmed ISM and an unsatisfactory response to available treatment. In part A, patients received a single dose of lirentelimab 0.0003, 0.001, 0.003, 0.01 or 0.03 mg kg-1; in part B, patients received one lirentelimab dose of 0.3 mg kg-1 or 1.0 mg kg-1; and in part C, patients received either 1.0 mg kg-1 lirentelimab every 4 weeks for 6 months or ascending doses of lirentelimab (one dose of 1 mg kg-1 followed by five doses of 3-10 mg kg-1 every 4 weeks). The primary endpoint was safety/tolerability. Secondary endpoints included changes from baseline in Mastocytosis Symptom Questionnaire (MSQ), Mastocytosis Activity Score (MAS) and Mastocytosis Quality of Life Questionnaire (MC-QoL) scores at 2 weeks after the final dose. RESULTS: In 25 patients with ISM (13 in parts A + B and 12 in part C; median age 51 years, 76% female, median 4.6 years from diagnosis), the most common treatment-related adverse events (AEs) were feeling hot (76%) and experiencing a headache (48%). No serious AEs occurred. Median MSQ and MAS symptom severity scores in part C improved (vs. baseline) across all symptoms [MSQ: skin (38-56%), gastrointestinal (49-60%), neurological (47-59%), musculoskeletal (26-27%); MAS: skin (53-59%), gastrointestinal (72-85%), neurological (20-57%), musculoskeletal (25%)]. Median MC-QoL scores improved across all domains: symptoms (39%), social life/functioning (42%), emotions (57%) and skin (44%). CONCLUSIONS: Lirentelimab was generally well tolerated and improved symptoms and quality of life in patients with ISM. The therapeutic potential of lirentelimab should be considered for ISM.

[Autoinflammatory syndromes]. / Autoinflammatorische Syndrome.

The concept of autoinflammation includes a heterogeneous group of monogenic and polygenic diseases. These are characterized by excessive activation of the innate immune system without antigen-specific T cells or autoantibodies. The diseases are characterized by periodic episodes of fever and increased inflammation parameters. Monogenic diseases include familial Mediterranean fever (FMF) and the newly described VEXAS (vacuoles, E1 enzyme, X­linked, autoinflammatory, somatic) syndrome. Heterogeneous diseases include adult-onset Still's disease and Schnitzler syndrome. Treatment is aimed at preventing the excessive inflammatory reaction in order to avoid long-term damage, such as amyloid A (AA) amyloidosis.

Neutrophilic dermatoses - Pathomechanistic concepts and therapeutic developments.

Neutrophilic dermatoses are a group of clinically heterogeneous diseases characterized by infiltration of neutrophils in the affected tissue. Skin symptoms comprise a spectrum of wheals, papules, plaques, pustules, nodules and ulcerations often in combination with systemic symptoms. Although the pathogenesis of these diseases has not yet been elucidated in depth, broad pathophysiological and clinical overlaps exist with autoinflammatory syndromes. Additionally, recent years have shown the relevance of the signaling pathways of TNF-α, IL-1, IL-12/23 and IL-17 in neutrophilic dermatoses. In this review, we present four selected neutrophilic dermatoses, namely pyoderma gangraenosum, Sweet syndrome, generalized pustular psoriasis and Schnitzler syndrome, discuss pathophysiological aspects and specifically address novel therapeutic options derived from the most recent pathophysiological findings.

[Granulomatous dermatoses]. / Granulomatöse Dermatosen.

The group of granulomatous dermatoses refers to a multitude of clinically different diseases, which are characterized by a histopathologically similar pattern of inflammation. The cause of granulomatous inflammatory reactions can be infections and also noninfectious stimuli, such as cell disintegration or foreign bodies. The aim of this immunological defence reaction is encapsulation in order to prevent further spread and delimitation from healthy tissue. This is histologically expressed as a granuloma in the sense of a circumscribed aggregation of histiocytes and multinucleated giant cells mostly in dermal connective tissue. The following can be histologically differentiated: sarcoid granuloma characterized by a sparse lymphocytic inflammatory infiltrate and tuberculous granuloma with central necrosis and denser lymphocytic inflammatory infiltrate. Neutrophilic granulocytes together with macrophages occur in suppurative granulomas and palisaded granulomas are characterized by peripherally arrayed macrophages.

Characterization of the effects on pruritus by novel treatments for atopic dermatitis.

Chronic pruritus is a common and debilitating symptom in patients with atopic dermatitis and contributes to impairment of quality of life. Effective treatment of pruritus should therefore be one of the main treatment goals in patients with atopic dermatitis. Pathophysiologically, the histamine-independent pruritogens interleukin-31, interleukin-13, and interleukin-4, have been shown to play a major role in atopic dermatitis. All three cytokines can mediate chronic pruritus via Janus kinase 1/2 signaling pathways. Novel drugs target these pathways and have shown rapid and sustained reduction of pruritus in patients with atopic dermatitis in clinical use and in phase II and III clinical trials. Here we summarize the published data on the effects of these drugs on itch parameters such as overall reduction in pruritus intensity and percent of patients with atopic dermatitis achieving a relevant reduction in itch. Each of the novel drugs shows very good effects on pruritus. These data offer hope for an even better and possibly more specific treatment of pruritus in patients with atopic dermatitis in the future. In addition, the different pharmacological approaches give us the chance to learn more about the pathophysiology of pruritus in atopic dermatitis.

The role of mast cells in autoinflammation.

The concept of autoinflammation was proposed to define a new class of immune disorders categorized by self-directed inflammation that is driven via activation of innate immune pathways. Within innate immunity, inflammasomes serve as intracellular signaling platforms to endogenous danger molecules and pathogens. Their key function is the cleavage of pro-interleukin-1ß (pro-IL-1ß) into its active form to promote inflammation and programmed cell death. A growing number of inflammasome sensors were described, among which NLR family pyrin domain containing 3 (NLRP3) is the best-studied sensor. Besides macrophages, monocytes, and other innate immune cells, mast cells (MCs) were shown to express functional inflammasomes too. Also, MCs are both, a source and target of IL-1ß. Here we review the functional relevance and role of MC inflammasomes and MC-derived IL-1ß in contributing to the inflammation at the skin, joints, and central nervous system in rare monogenic autoinflammatory conditions and also common inflammatory and degenerative diseases.

The global impact of the COVID-19 pandemic on the management and course of chronic urticaria.

INTRODUCTION: The COVID-19 pandemic dramatically disrupts health care around the globe. The impact of the pandemic on chronic urticaria (CU) and its management are largely unknown. AIM: To understand how CU patients are affected by the COVID-19 pandemic; how specialists alter CU patient management; and the course of CU in patients with COVID-19. MATERIALS AND METHODS: Our cross-sectional, international, questionnaire-based, multicenter UCARE COVID-CU study assessed the impact of the pandemic on patient consultations, remote treatment, changes in medications, and clinical consequences. RESULTS: The COVID-19 pandemic severely impairs CU patient care, with less than 50% of the weekly numbers of patients treated as compared to before the pandemic. Reduced patient referrals and clinic hours were the major reasons. Almost half of responding UCARE physicians were involved in COVID-19 patient care, which negatively impacted on the care of urticaria patients. The rate of face-to-face consultations decreased by 62%, from 90% to less than half, whereas the rate of remote consultations increased by more than 600%, from one in 10 to more than two thirds. Cyclosporine and systemic corticosteroids, but not antihistamines or omalizumab, are used less during the pandemic. CU does not affect the course of COVID-19, but COVID-19 results in CU exacerbation in one of three patients, with higher rates in patients with severe COVID-19. CONCLUSIONS: The COVID-19 pandemic brings major changes and challenges for CU patients and their physicians. The long-term consequences of these changes, especially the increased use of remote consultations, require careful evaluation.

Spectrum of Genetic Autoinflammatory Diseases Presenting with Cutaneous Symptoms.

Autoinflammatory diseases comprise a group of chronic disabling entities characterized by inflammation without the presence of infectious agents, auto-antibodies or antigen-specific T-cells. Many autoinflammatory diseases are caused by monogenic defects, which lead to disturbed immune signalling with release of proinflammatory mediators. In addition to interleukin-1ß and interleukin-18, interferons play a key role in the pathophysiology of these disorders. Patients with autoinflammatory diseases show a broad variety of clinical symptoms, including skin involvement. Wheals, pustules and ulcerative lesions are the most common cutaneous findings observed. Knowledge of the clinical presentation of autoinflammatory diseases is crucial for establishing the diagnosis and guiding appropriate treatment. This review focuses on the dermatological findings in selected autoinflammatory disorders based on their distinct pathomechanisms.

Treatment of urticarial vasculitis: A systematic review.

Urticarial vasculitis (UV) is a difficult-to-treat condition characterized by long-lasting urticarial rashes and histopathologic findings of leukocytoclastic vasculitis. Treatment is dictated by the severity of skin and systemic involvement and the underlying systemic disease. This is a comprehensive systematic review of the efficacy of current UV treatment options. We searched for relevant studies in 7 databases, including MEDLINE, Scopus, and Web of Science. In total, 261 eligible studies and 789 unique patients with UV were included in the systematic review. Most patients with UV are adult women with chronic (≥6 weeks) and systemic disease. UV is mostly idiopathic but can be associated with drugs, malignancy, autoimmunity, and infections. It usually resolves with their withdrawal or cure. Corticosteroids are effective for the treatment of skin symptoms in more than 80% of patients with UV. However, their long-term administration can lead to potentially serious adverse effects. The addition of immunomodulatory or immunosuppressive agents often allows corticosteroid tapering and improves the efficacy of therapy. Biologicals, including omalizumab, as well as corticosteroids, cyclophosphamide, dapsone, mycophenolate mofetil, plasmapheresis, colchicine, hydroxychloroquine, intravenous immunoglobulin, nonsteroidal anti-inflammatory drugs, and cyclosporine, can be effective for both skin and systemic symptoms in patients with UV. H1-antihistamines, montelukast, danazol, H2-antihistamines, pentoxifylline, doxepin, and tranexamic acid are not effective in most patients with UV. As of yet, no drugs have been approved for UV, and management recommendations are based mostly on case reports and retrospective studies. Prospective studies investigating the effects of treatment on the signs and symptoms of UV are needed.