The Diagnostic Workup in Chronic Spontaneous Urticaria-What to Test and Why

Autoimmune Diseases and Low Baseline IgE in Chronic Spontaneous Urticaria: A Clinical and Therapeutic Prospective Analysis in Real-Life Clinical Practice

BACKGROUND

Autoimmunity contributes to the pathogenesis of chronic spontaneous urticaria (CSU). The subtyping of CSU has revealed an autoimmune form of CSU. Despite autoimmune diseases having been associated with CSU, there are few prospective studies that have evaluated the characteristics and biomarkers of patients with CSU and autoimmune disease in a real-life practice setting.

OBJECTIVE

To evaluate the presence of specific biomarkers for the presence of autoimmune disease in CSU and to analyze the clinical and therapeutic features of patients with CSU and autoimmune disease.

METHODS

The clinical, laboratory, and therapeutic features of patients with CSU at a tertiary-level center were prospectively collected. Data obtained were compared in function of the presence/absence of autoimmune disease and typified according to IgE levels.

RESULTS

Patients with CSU who had associated autoimmune disease corresponded to middle-aged women with a common pattern of blood test findings: both low baseline IgE and high-affinity receptor of IgE expression, basopenia, eosinopenia, higher baseline erythrocyte sedimentation rate and D-dimer, increased presence of antinuclear antibodies, IgG against thyroid peroxidase, and positive autologous serum skin test result. Total baseline IgE less than or equal to 43.8 IU/mL was both the optimal cutoff to predict autoimmune disease in the CSU cohort and a significant risk factor for the presence of autoimmune disease in the regression analysis.

CONCLUSIONS

In real-life clinical practice, characteristics of patients with CSU and autoimmune disease share common features with type IIb autoimmune CSU. Total baseline IgE less than or equal to 43.8 IU/mL has been detected as a possible biomarker of autoimmune disease in patients with CSU.

Anti-heat shock protein 10 IgG in chronic spontaneous urticaria: Relation with miRNA-101-5p and platelet-activating factor

BACKGROUND

Anti-heat shock protein (HSP) autoantibodies are detected in autoimmune diseases. We sought to ascertain whether anti-HSP10 IgG is present in patients with CSU and to elucidate the role of HSP10 in CSU pathogenesis.

METHOD

Using a human proteome microarray, six potential autoantibodies had higher expression in 10 CSU samples compared with 10 normal controls (NCs). Among them, HSP10 IgG autoantibody was quantified by immune dot-blot assay in sera from 86 CSU patients and 44 NCs. The serum levels of HSP10 and microRNA-101-5p were measured in CSU patients and NCs. The effects of HSP10 and miR-101-5p on mast cell degranulation in response to IgE, compound 48/80, and platelet-activating factor (PAF) were investigated.

RESULTS

CSU patients had higher IgG positivity to HSP10 (40.7% vs. 11.4%, p = .001), lower serum HSP10 levels (5.8 ± 3.6 vs. 12.2 ± 6.6 pg/mL, p < .001) than in NCs, and their urticaria severity was associated with anti-HSP10 IgG positivity, while HSP10 levels were related to urticaria control status. MiR-101-5p was increased in CSU patients. PAF enhanced IL4 production in PBMCs from CSU patients. IL-4 upregulated miR-101-5p and reduced HSP10 expression in keratinocytes. Transfection of miR-101-5p reduced HSP10 expression in keratinocytes. MiR-101-5p promoted PAF-induced mast cell degranulation, while HSP10 specifically prevented it.

CONCLUSION

A new autoantibody, anti-HSP10 IgG was detected in CSU patients, which showed a significant correlation with UAS7 scores. A decreased serum HSP10 level was associated with upregulation of miR-101-5p due to increased IL-4 and PAF in CSU patients. Modulation of miR-101-5p and HSP10 may be a novel therapeutic approach for CSU.

Biomarkers of Autoimmune Chronic Spontaneous Urticaria

PURPOSEOF REVIEW

Chronic spontaneous urticaria and chronic inducible urticaria (CSU/CindU) are caused by mast cell and basophil activation leading to degranulation and the release of histamine and several other mediators. Three kinds of factors can trigger mast cells in CSU: (1) activation of stimulating receptor(s) on the mast cell membrane, (2) upregulation of certain receptor(s), and (3) intracellular dysregulation in signaling with overexpression of the spleen tyrosine kinase (SYK) or reduced activation of the inhibitory Src homology 2 (SH2)-containing inositol phosphatases (SHIP)-related pathways. In CSU, two major endotypes exist based on the primary receptor activating mechanism: type I hypersensitivity (IgE-mediated, directed against auto-allergens) and type IIb (autoimmune, via IgG autoantibodies directed against IgE or the IgE-receptor). Their treatment responses vary. We discuss in vitro and in vivo biomarkers.

RECENT FINDINGS

Patients with auto-allergic CSU have clinical characteristics that can distinguish them partly from those with autoimmune CSU. Most importantly, their disease generally presents a less aggressive course, a better response to second generation (up-dosed) antihistamines and a good response to omalizumab, if necessary. Meanwhile, autoimmune CSU/CindU patients fare less well and often need immunosuppressive drugs. Biomarkers that might help endotype CSU/CindU patients and select the most appropriate treatment, dose, and duration, e.g., for autoallergic CSU, high total IgE and IgE against auto-allergens; for autoimmune CSU, low IgE, basopenia, and IgG against autoantigens like thyroid peroxidase and a positive autologous serum skin test (but sometimes also positive in autoallergy). Some biomarkers are easily accessible but of low specificity; others are highly specific but more futuristic.

The many faces of pediatric urticaria

Urticaria is a common disease that can affect individuals of all age groups, with approximately one-quarter of the population experiencing it at least once in their lifetime. Lesions characterized by erythema and itchy hives can appear anywhere on the body. These can vary in size ranging from millimeters to centimeters, and typically clear within 24 h. About 40% of patients with urticaria have accompanying angioedema, which involves localized deep tissue swelling. Urticaria usually occurs spontaneously and is classified into acute and chronic forms, with the latter referring to a condition that lasts for more than 6 weeks. The prevalence of chronic urticaria in the general population ranges from 0.5% to 5%, and it can either be inducible or spontaneous. The most common form of pediatric urticaria is acute and is usually self-limiting. However, a broad differential diagnosis should be considered in children with urticaria, particularly if they also have accompanying systemic complaints. Differential diagnoses of pediatric urticaria include chronic spontaneous urticaria, chronic inducible urticaria, serum sickness-like reaction, urticarial vasculitis, and mast cell disorders. Conditions that can mimic urticaria, including but not limited to cryopyrinopathies, hyper IgD syndrome, Periodic Fever, Aphthous Stomatitis, Pharyngitis and Adenitis (PFAPA), Tumor Necrosis Factor Receptor Associated Periodic Syndrome (TRAPs), and Schnitzler syndrome should also be considered. The many faces of pediatric urticaria can be both easy and confusing. A pragmatic approach relies on clinical foresight and understanding the various forms of urticaria and their potential mimickers. This approach can pave the way for an accurate and optimized diagnostic approach in children with urticaria.

Omalizumab for Patients with Chronic Spontaneous Urticaria: A Narrative Review of Current Status

Chronic spontaneous urticaria (CSU) is a debilitating inflammatory disorder of the skin, characterized by a fluctuating natural history, a complex mechanism of action, and a significant burden on patients, including effect on quality of life, development of psychosocial disorders, and a range of comorbidities. Recent international guidelines recommend a therapeutic approach of first-line treatment with second generation H1-antihistamines and second-line treatment with the biologic omalizumab. Here, the salient aspects of CSU and current status of data for omalizumab for patients with CSU are reviewed, with a focus on mechanism of action, efficacy and real-world effectiveness (including patient outcomes, response, relapse, and remission), and safety (including consideration of the risk of anaphylaxis). The review also considers recent data on COVID-19, CSU, and omalizumab and presents our perspective on future needs. Overall, the data suggest that omalizumab is an effective and well-tolerated treatment for patients with CSU that provides benefits for a wide range of patients.

Chronic spontaneous urticaria: new evidences on the role of autoimmunity

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of the recent advancements and relevance of the autoimmune theories in chronic spontaneous urticaria (CSU).

RECENT FINDINGS

Two primary types of autoimmunity, Type I and Type IIb, have emerged as major contributors to CSU, characterized by immunoglobulin E (IgE) and immunoglobulin G (IgG) autoantibodies, respectively. Genetic evidence supports the notion that CSU shares more similarities with other autoimmune diseases rather than atopic diseases. Novel autoallergens such as FcεRI and tissue transglutaminase have been identified, contributed to our understanding of autoimmune mechanisms. Furthermore, the potential overlap between Type I and Type IIb autoimmunity has been recognized. Evaluating the autoimmune status of CSU patients through biomarkers and understanding their clinical implications is vital for effective management. For instance, CSU patients with Type IIb autoimmunity, with or without coexisting Type I autoimmunity, may exhibit resistance to H1-antihistamines and omalizumab treatment but could potentially respond well to cyclosporine or Bruton's tyrosine kinase inhibitors.

SUMMARY

Further investigations are needed to explore new autoallergens and autoantibodies in CSU, establishing their connection to the development of autoimmunity. The efficacy of novel drugs targeting different mechanisms should be examined to determine their responses in both autoimmune CSU and nonautoimmunity-related CSU.

Systematic Review and Critical Appraisal of Urticaria Clinical Practice Guidelines: A Global Guidelines in Dermatology Mapping Project (GUIDEMAP)

BACKGROUND

Management of urticaria can be optimized with clinical practice guidelines (CPGs). However, the quality of recent urticaria CPGs remains unclear.

OBJECTIVE

To identify and appraise urticaria CPGs worldwide published in the last 5 years.

METHODS

A search for relevant urticaria CPGs was conducted between January 1, 2017, and May 31, 2022, using the following databases: MEDLINE, Embase, National Institute for Health and Care Excellence (NICE) Evidence Search, Guidelines International Network, ECRI Guidelines Trust, Australian Clinical Practice Guidelines, Trip Medical Database, and DynaMed. The included CPGs were critically appraised using the Appraisal of Guidelines for Research and Evaluation (AGREE) II instrument, Lenzer et al's red flags, and the Institute of Medicine (IOM) criteria of trustworthiness.

RESULTS

We included 21 urticaria CPGs. Most guidelines reviewed treatment recommendations of chronic spontaneous urticaria. The majority of guidelines were from European and Asian countries with high and high-middle sociodemographic index, written in English, and openly accessible. Seventeen guidelines (81%) had at least 1 AGREE II domain rated poor quality. Applicability, rigor of development, and stakeholder involvement were the 3 AGREE II domains that scored the lowest across guidelines. Appraisal with Lenzer et al's red flags showed that 18 guidelines (86%) raised at least 1 red flag indicating potential bias. The top 3 domains raising red flags were: no inclusion of nonphysician experts/patient representative/community stakeholders, no or limited involvement of a methodologist in the evaluation of evidence, and lack of external review. Based on IOM's criteria of trustworthiness, 20 guidelines (95%) had 1 or more criteria that did not meet best practice standards. The 3 domains with the highest number of best practice standards not met were updating procedures, rating strength of recommendations, and external review. Guidelines scored highest for the AGREE II domains of defining scope and purpose and clarity of presentation, and had the most fully met IOM's best practice standard for articulation of recommendations. However, only 1 urticaria CPG by NICE was identified as rigorously developed across all 3 appraisal tools.

CONCLUSIONS

The quality of urticaria CPGs in the last 5 years varied widely. Only the NICE urticaria guideline consistently demonstrated excellent quality, high trustworthiness, and low risk of bias. Use of a rigorous framework to rate certainty of evidence and grade strength of recommendation, involvement of methodologists, stakeholder engagement with external review, and clear guidance for updating can help improve the quality of future CPGs.

Urticaria and mimickers of urticaria

Urticaria is a common skin condition encountered across various specialties in medicine, especially in dermatology and allergy/immunology practice. It has a heterogeneous presentation hence it is unsurprising that many skin conditions may be confused with urticaria. Urticaria may present as acute or chronic urticaria, the latter can be further categorised into chronic spontaneous and chronic inducible. In this article, we explore, explain, and summarise various skin lesions that are considered mimickers of urticaria, to promote understanding of each of the conditions highlighted, improve recognition, and reduce misdiagnosis.

Anti-TPO IgG/Total IgE Ratio: Biomarker for Omalizumab Response Prediction in Chronic Spontaneous Urticaria

BACKGROUND

According to recently published data, low total IgE, elevated IgG-anti-TPO, and a high IgG-anti-TPO/total IgE ratio are good biomarkers for subtype IIb autoimmune chronic spontaneous urticaria (CSU), which is frequently refractory to antihistamines and omalizumab.

OBJECTIVES

The aim of the study was to evaluate IgG-anti-TPO/total IgE ratio's utility in omalizumab response prediction.

METHODS

Retrospective study of CSU patients treated with omalizumab at a UCARE between January 2009 and February 2022. Patients were grouped according to response in the first 16 weeks of treatment: responders UAS7 < 7 versus partial/non-responders UAS7≥7. Total IgE, IgG-anti-TPO, and IgG-anti-TPO/total IgE ratio were compared. Other inflammatory biomarkers - eosinophils, basophils, C-reactive protein, erythrocyte sedimentation rate, and d-dimer - were analyzed.

STATISTICAL ANALYSIS

SPSS® (v25.0), p < 0.05 statistically significant.

RESULTS

Total of 175 patients, 140 (80%) women, median age 49 [9-88] years, mean CSU duration pre-omalizumab 5.6 ± 8.2 [0-54] years, omalizumab duration 3.2 ± 2.5 [0-12] years. 116 (66%) had angioedema, 77 (44%) inducible chronic urticaria, 60 (34%) atopy, 24 (14%) autoimmune disease. With omalizumab 300 mg q4 weeks, 69% were responders and 31% partial/non-responders. Although not reaching significant differences, mean total IgE values were lower and mean IgG-anti-TPO values were higher in partial/non-responders versus responders (152 vs. 242 kU/L, p = 0.207, and 38.3 vs. 25.7 U/mL, p = 0.408, respectively). A higher IgG-anti-TPO/total IgE ratio was significantly associated with poorer response to omalizumab (p = 0.040). A cut-off >0.154 increased 10 times the odd of poorer response [95% CI 4.62-22], AUC 0.872, p < 0.001, with 87.7% sensitivity, although the low specificity (22.4%) does not allow the assumption of response with values <0.154. Other laboratory biomarkers did not show significant differences between partial/non-responders versus responders.

CONCLUSIONS

A high IgG-anti-TPO/total IgE ratio was a good biomarker of poor response to omalizumab in our CSU cohort, with a cut-off >0.154 increasing 10 times the odd of poorer response.

Chronic Spontaneous Urticaria: How to Measure It and the Need to Define Treatment Success

Chronic spontaneous urticaria (CSU) is a complex skin disease characterized by the spontaneous appearance of wheals, angioedema, or both, for more than 6 weeks. Many patients experience a relapsing-remitting disease course for years. Owing to the unpredictability of wheal recurrence and the severity of pruritis, patients suffer considerable impairment in their quality of life. Physicians face multiple challenges, not least of which is a lack of clear guidance on what constitutes "treatment success". There is a lack of awareness of which measures should be used to best assess the various aspects of CSU, including disease activity, disease control, and quality of life-which themselves each comprise multiple components-and how to apply the results of each score to treatment decision-making. Although the overarching aim of treatment is for patients to be completely free of signs and symptoms of CSU, a more realistic definition of "treatment success" is needed to guide ongoing, long-term disease management for each individual patient. In this review, we consider what lessons can be learned from the current evidence base to provide further direction toward a universal definition of "treatment success".

S3 Guideline Urticaria. Part 1: Classification and diagnosis of urticaria - German-language adaptation of the international S3 Guideline

The lifetime prevalence of urticaria, a severe allergic disease, is almost 20%. It not only limits the quality of life of those affected, but also their general performance at work and in their daily activities. This publication is the first section of the Urticaria Guideline. It covers the classification and diagnosis of urticaria, taking into account the major advances in research into its causes, triggering factors and pathomechanisms. It also addresses strategies for the efficient diagnosis of the different subtypes of urticaria. This is crucial for individual, patient-oriented treatment, which is covered in the second part of the guideline, published separately. This German-language guideline was developed according to the criteria of the AWMF on the basis of the international English-language S3 guideline with special consideration of health system characteristics in the German-speaking countries. This first part of the guideline describes the classification of urticaria, distinguishing spontaneously occurring wheals (hives) and angioedema from forms of urticaria with inducible symptoms. Urticaria is defined as sudden onset of wheals, angioedema, or both, but is to be distinguished from conditions in which wheals occur as a short-term symptom, such as anaphylaxis. The diagnosis is based on (a limited number of) laboratory tests, but especially on medical history. In addition, validated instruments are available to measure the severity, activity and course of the disease.

Chronic spontaneous urticaria guidelines: What is new?

Urticaria is a heterogeneous inflammatory disorder that can be acute or chronic and is defined by the appearance of wheals, angioedema, or both. Very recently, the newest update and revision of the international European Academy of Allergy and Clinical Immunology/Global Allergy and Asthma European Network/European Dermatology Forum/Asia Pacific Association of Allergy Asthma Clinical Immunology guideline for the definition, classification, diagnosis, and management of urticaria was published. It aims to help primary care physicians and specialists in the management of their patients with urticaria. The guideline applied the Grading of Recommendations Assessment Development and Evaluations approach to developing consensus recommendations. These recommendations were then discussed in a Delphi conference that included more than 250 specialists in the field, and they are endorsed by more than 50 international societies. Here, we highlight changes from previous versions of the international urticaria guideline and their impact on clinical practice.

Pediatric chronic spontaneous urticaria: a brief clinician's guide

INTRODUCTION

Chronic urticaria (CU) appears with daily or intermittent/recurrent wheals with/without angioedema for more than six weeks. When no specific eliciting factors are found, chronic urticaria is defined as spontaneous (CSU). Up to 50% of patients with CSU do not respond to therapy, leading to a prolonged disease course and the need for expensive therapies, impacting the quality of life (QoL) and healthcare resources.

AREAS COVERED

: Diagnosis of CSU is made when other potential causes of chronic urticaria are excluded. CSU therapy aims to achieve complete control of symptoms and normalization of QoL. Current treatment options for urticaria aim to target mast cell mediators such as histamine, or activators, such as autoantibodies. Guidelines recommend starting with second generation antihistamines (sgAHs) and adding omalizumab therapy if symptoms are not controlled. This review aims to provide a practical guide for CSU in the pediatric population.

EXPERT OPINION

: Treatment options for pediatric CSU are primarily based on adult data that have been extrapolated for children. Current guidelines should be re-evaluated based on pediatric data, new biological treatments, and the COVID-19 pandemic. Future research is needed to investigate strategies to personalize current treatments and identify potential predictive biomarkers.

Unmet Medical Needs in Chronic, Non-communicable Inflammatory Skin Diseases

An estimated 20-25% of the population is affected by chronic, non-communicable inflammatory skin diseases. Chronic skin inflammation has many causes. Among the most frequent chronic inflammatory skin diseases are atopic dermatitis, psoriasis, urticaria, lichen planus, and hidradenitis suppurativa, driven by a complex interplay of genetics and environmental factors. Autoimmunity is another important cause of chronic skin inflammation. The autoimmune response may be mainly T cell driven, such as in alopecia areata or vitiligo, or B cell driven in chronic spontaneous urticaria, pemphigus and pemphigoid diseases. Rare causes of chronic skin inflammation are autoinflammatory diseases, or rheumatic diseases, such as cutaneous lupus erythematosus or dermatomyositis. Whilst we have seen a significant improvement in diagnosis and treatment, several challenges remain. Especially for rarer causes of chronic skin inflammation, early diagnosis is often missed because of low awareness and lack of diagnostics. Systemic immunosuppression is the treatment of choice for almost all of these diseases. Adverse events due to immunosuppression, insufficient therapeutic responses and relapses remain a challenge. For atopic dermatitis and psoriasis, a broad spectrum of innovative treatments has been developed. However, treatment responses cannot be predicted so far. Hence, development of (bio)markers allowing selection of specific medications for individual patients is needed. Given the encouraging developments during the past years, we envision that many of these challenges in the diagnosis and treatment of chronic inflammatory skin diseases will be thoroughly addressed in the future.

The international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for the definition, classification, diagnosis, and management of urticaria

This update and revision of the international guideline for urticaria was developed following the methods recommended by Cochrane and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group. It is a joint initiative of the Dermatology Section of the European Academy of Allergology and Clinical Immunology (EAACI), the Global Allergy and Asthma European Network (GA²LEN) and its Urticaria and Angioedema Centers of Reference and Excellence (UCAREs and ACAREs), the European Dermatology Forum (EDF; EuroGuiDerm), and the Asia Pacific Association of Allergy, Asthma and Clinical Immunology with the participation of 64 delegates of 50 national and international societies and from 31 countries. The consensus conference was held on 3 December 2020. This guideline was acknowledged and accepted by the European Union of Medical Specialists (UEMS). Urticaria is a frequent, mast cell-driven disease that presents with wheals, angioedema, or both. The lifetime prevalence for acute urticaria is approximately 20%. Chronic spontaneous or inducible urticaria is disabling, impairs quality of life, and affects performance at work and school. This updated version of the international guideline for urticaria covers the definition and classification of urticaria and outlines expert-guided and evidence-based diagnostic and therapeutic approaches for the different subtypes of urticaria.