The Chronic Urticaria Registry: rationale, methods and initial implementation

Global productivity, international collaborations, and research trends in chronic spontaneous urticaria: A bibliometric overview

Background

The treatment of chronic spontaneous urticaria (CSU) remains a challenge despite novel therapies such as omalizumab. With growing international interest in research on CSU, a comprehensive review of the global productivity, collaborations, and trending topics in CSU research may help inform future directions in patient management.

Objectives

This study aims to outline the trends in CSU research by using bibliometric analysis, focusing specifically on global productivity, collaborative efforts, and emerging research topics spanning from 1977 to 2023.

Methods

Publications related to CSU, including original articles, reviews, and letters, were sourced from the Web of Science Core Collection, and statistical analyses were performed using the Bibliometrix package in R and IBM SPSS Statistics.

Results

A total of 2940 publications from 77 countries were analyzed. CSU research activity has increased exponentially since 2010, with more than half of the publications (50.2% [1477 of 2940]) published since 2016. These publications appeared in allergy, immunology, and dermatology journals led predominantly by European, Asian, and American researchers. International collaborations rose from 11.3% to 22.2%. Shifts in research focus, such as a shift in treatments from antihistamines to omalizumab, and growing emphasis on quality of life were noted.

Conclusion

This study revealed a dynamic and increasingly collaborative CSU research landscape, emphasizing the need for continuous global partnerships to enhance treatment outcomes and improve patients' quality of life. Challenges regarding access to advanced therapies persist, highlighting the importance of expanding international collaborations and inclusive research practices.

Inequalities in Access to Specialist Allergy Services in the United Kingdom: A Report From the BSACI Registry for Immunotherapy (BRIT)

BACKGROUND

There is an unmet need for specialist allergy treatment in the United Kingdom. Allergen immunotherapy and treatment with omalizumab for chronic spontaneous urticaria (CSU) are key markers for these services. The British Society for Allergy and Clinical Immunology (BSACI) Registry for Immunotherapy (BRIT) is a national project to record the real-world effectiveness, safety and access to treatment for aero-allergen, venom and peanut immunotherapy as well as omalizumab for CSU.

METHODS

We described participant demographics, the index of multiple deprivation (IMD) and access to treatment from the registry launch. Data for 1835 participants were available for analysis from 63 centres enrolled between 1st October 2018 and 24th August 2023.

RESULTS

96.5% (1771/1835) were living in England, with only 3.5% (64) being from the devolved nations. 14.4% (251/1748) were in the most affluent IMD decile compared to 4.5% (78/1748) in the most deprived IMD decile. White participants were 1.74 times more likely to be referred directly from primary care compared to people of Asian, black, mixed or other minority ethnic groups. Instead, these groups were referred more frequently from secondary or tertiary hospital services. The median distance travelled from home to the treatment centre was 15.2 miles, with evidence of clustering around specialist centres.

CONCLUSIONS

We have described disparities and unwarranted variation in the provision of treatment around the UK. The data suggest that there is limited access to immunotherapy in the devolved nations. Access is also reduced by socioeconomic deprivation. White participants were more likely to receive a direct referral from primary care than those from other ethnic groups whose referral pathways were more complex. Registry data are limited by participant enrolment and may have selection bias. Nevertheless, BRIT has highlighted inequity in access to specialist allergy services in the UK.

Elevated cutaneous expression of stem cell factor in chronic spontaneous urticaria: a prospective cohort study

BACKGROUND

Tissue expression of endothelial cell markers of microcirculatory changes in chronic spontaneous urticaria (CSU) is poorly understood.

OBJECTIVES

To explore the expression of specific endothelial cell markers [stem cell factor (SCF), vascular endothelial growth factor (VEGF) and membrane attack complex (MAC)] in lesional and nonlesional CSU skin through immunohistochemistry (IHC) and in serum.

METHODS

Lesional and nonlesional skin biopsies from patients with CSU (n = 23) and healthy controls (n = 9) were studied by IHC for expression of SCF, VEGF and MAC. In this population, we also investigated blood levels of VEGF and SCF. Patients were also assessed for clinical characteristics, disease activity and markers of autoimmune CSU. The study was registered at ClinicalTrials.gov (NCT03443362).

RESULTS

Epidermal SCF reactivity was significantly higher in CSU lesional skin than in healthy skin (P = 0.026). In the dermis, SCF immunoreactivity was seen particularly in endothelial, perivascular and epithelial cells. In CSU lesional skin, the mean perivascular SCF staining was significantly more intense than in healthy controls (P < 0.001). Furthermore, CSU nonlesional skin also showed significantly higher SCF staining in dermal perivascular cells than in healthy controls (P < 0.001). Patients with CSU had the highest SCF immunoreactivity scores in the epidermis and/or on dermal endothelial cells. These patients did not have significantly higher SCF serum levels.

CONCLUSIONS

To our knowledge, this is the first study to show elevated cutaneous expression of SCF in CSU. These findings underline the potential therapeutic possibilities of anti-Kit antibodies in CSU treatment.

Key differences between chronic inducible and spontaneous urticaria

Introduction

The latest international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for urticaria recommends limited laboratory testing for chronic spontaneous urticaria (CSU) and selective testing for only certain chronic inducible urticaria (CIndU) subtypes, though the rationale for these recommendations is poorly explained. This study aimed to improve the understanding of CIndU subtypes by comprehensively comparing their demographic, clinical, and laboratory characteristics with those of the better-characterized CSU.

Methods

We conducted a retrospective analysis of 567 patients (median age 41 years, 67% female) diagnosed with CSU, symptomatic dermographism (SD), cold urticaria (ColdU), cholinergic urticaria (CholU), and delayed pressure urticaria (DPU).

Results

Our findings revealed that patients with SD, ColdU, and CholU had lower levels of C-reactive protein (CRP), higher total serum immunoglobulin E (IgE) levels, and higher basophil counts compared to CSU patients. These subtypes also had distinct demographic and clinical features, such as a younger age of onset and a longer disease duration. In contrast, patients with DPU had significantly higher CRP levels and neutrophil counts compared to those with CSU.

Discussion

These findings highlight the heterogeneity among chronic urticaria subtypes, suggesting that a tailored approach to laboratory testing may be more effective. The distinct immunological and clinical features observed in CIndU subtypes suggest a need for subtype-specific diagnostic and therapeutic guidelines.

The Definition, Classification, and History of Urticaria

The term "urticaria" was first introduced by William Cullen in the eighteenth century. Urticaria is a common mast cell-mediated cutaneous disease presenting with pruritic wheals, angioedema, or both. It is classified as acute (≤6 weeks) or chronic (>6 weeks) and as spontaneous (no definite triggers) or inducible (definite and subtype-specific triggers). The international urticaria guideline on the definition, classification, diagnosis, and management of urticaria is revised every 4 years. The global network of Urticaria Centers of Reference and Excellence, the biggest and most active consortium of urticaria specialists, offers physicians and patients several research, educational, and digital care initiatives.

Non-Skin Related Symptoms Are Common in Chronic Spontaneous Urticaria and Linked to Active and Uncontrolled Disease: Results From the Chronic Urticaria Registry

BACKGROUND

Chronic spontaneous urticaria (CSU) can present with non-skin related symptoms (NSRS), including recurrent unexplained fever, joint, bone, or muscle pain (JBMP), and malaise, which also occur in other conditions that manifest with wheals (eg, urticarial vasculitis or autoinflammatory disorders) or without wheals (eg, infection).

OBJECTIVE

We sought to determine the rate of patients with CSU affected by fever, JBMP, and malaise, their trigger factors, links with clinical and laboratory characteristics, and their impact on everyday life and treatment responses.

METHODS

We analyzed baseline data from the Chronic Urticaria Registry of 2,521 patients with CSU who were aged 16 years or older.

RESULTS

One third of CSU patients (31.2%; 786 of 2,521) had one or more NSRS, including recurrent fever (5.3%), JBMP (19.1%), and/or malaise (18.6%). In a multivariable analysis, having one or more of these NSRS correlated with food and infection as trigger factors of urticaria (adjusted odds ratio [aOR] = 1.7 and 1.5), wheals of 24 hours or greater duration (aOR = 2.5), sleep disturbance (aOR = 2.4), anxiety (aOR = 2.8), comorbid atopic dermatitis (aOR = 2.1), gastrointestinal disease (aOR = 1.8), elevated leukocytes (aOR = 1.7) and erythrocyte sedimentation rate (aOR = 1.5). In a bivariate analysis, these NSRS were additionally associated with higher disease activity (weekly Urticaria Activity Score, median: 21 vs 14; P = .009), longer disease duration (years, median: 2 vs 1; P = .001), the presence of angioedema (74.6% vs 58.7%; P < .001), worse quality of life (Chronic Urticaria Quality of Life Questionnaire, median: 42 vs 29; P < .001) and more frequent poor control of CSU (78% vs 69%; P < .001).

CONCLUSIONS

The presence of NSRS in a subpopulation of patients with CSU points to the need for better control of the disease, exclusion of comorbid conditions, and/or exclusion of urticarial vasculitis and urticarial autoinflammatory diseases.

Comorbid Inducible Urticaria Is Linked to Non-Autoimmune Chronic Spontaneous Urticaria: CURE Insights

BACKGROUND

Patients with chronic spontaneous urticaria (CSU) can have comorbid inducible urticaria (CIndU). How comorbid CIndU affects patients and their CSU is largely unclear.

OBJECTIVE

To compare patients with CSU with and without comorbid CIndUs for differences in demographic features, clinical characteristics, and laboratory markers.

METHODS

We analyzed 708 patients with CSU of our Urticaria Center of Reference and Excellence enrolled in CURE, the chronic urticaria registry. CURE data collected until October 2022 were used to compare patients with and without comorbid CIndU for their demographic characteristics, disease onset, activity, impact, and control, as well as concomitant allergic and autoimmune diseases and laboratory parameters associated with autoimmune CSU.

RESULTS

Of 708 patients with CSU, 247 (35%) had comorbid CIndU. Compared with patients with standalone CSU, patients with CSU with comorbid CIndU were significantly younger, had earlier disease onset, longer disease duration, higher impact on quality of life, and a higher rate of concomitant allergic diseases. Moreover, patients with CSU with comorbid CIndU less often had features linked to autoimmune CSU such as angioedema, concomitant autoimmune diseases, eosinopenia, low levels of total IgE, and low total IgE combined with elevated anti-thyroid peroxidase IgG.

CONCLUSIONS

Autoimmune CSU may be less common in patients with comorbid CIndU than without, and comorbid CIndU may point to autoallergic CSU.

CRUSE® -An innovative mobile application for patient monitoring and management in chronic spontaneous urticaria

BACKGROUND

Chronic spontaneous urticaria (CSU) is unpredictable and can severely impair patients' quality of life. Patients with CSU need a convenient, user-friendly platform to complete patient-reported outcome measures (PROMs) on their mobile devices. CRUSE® , the Chronic Urticaria Self Evaluation app, aims to address this unmet need.

METHODS

CRUSE® was developed by an international steering committee of urticaria specialists. Priorities for the app based on recent findings in CSU were defined to allow patients to track and record their symptoms and medication use over time and send photographs. The CRUSE® app collects patient data such as age, sex, disease onset, triggers, medication, and CSU characteristics that can be sent securely to physicians, providing real-time insights. Additionally, CRUSE® contains PROMs to assess disease activity and control, which are individualised to patient profiles and clinical manifestations.

RESULTS

CRUSE® was launched in Germany in March 2022 and is now available for free in 17 countries. It is adapted to the local language and displays a country-specific list of available urticaria medications. English and Ukrainian versions are available worldwide. From July 2022 to June 2023, 25,710 observations were documented by 2540 users; 72.7% were females, with a mean age of 39.6 years. At baseline, 93.7% and 51.3% of users had wheals and angioedema, respectively. Second-generation antihistamines were used in 74.0% of days.

CONCLUSIONS

The initial data from CRUSE® show the wide use and utility of effectively tracking patients' disease activity and control, paving the way for personalised CSU management.

Patients With Chronic Spontaneous Urticaria Who Have Wheals, Angioedema, or Both, Differ Demographically, Clinically, and in Response to Treatment-Results From CURE

BACKGROUND

Patients with chronic spontaneous urticaria (CSU) have spontaneous wheals (W), angioedema (AE), or both, for longer than 6 weeks. Clinical differences between patients with standalone W, standalone AE, and W and AE (W+AE) remain incompletely understood.

OBJECTIVE

To compare W, AE, and W+AE CSU patients regarding demographics, disease characteristics, comorbidities, disease burden, and treatment response.

METHODS

Baseline data from 3,698 CSU patients in the ongoing, prospective, international, multicenter, observational Chronic Urticaria REgistry (CURE) were analyzed (data cut: September 2022).

RESULTS

Across all CSU patients, 59%, 36%, and 5% had W+AE, W, and AE, respectively. The W+AE patients, compared with W and AE patients, showed the lowest male-to-female ratio (0.33), higher rates of concomitant psychiatric disease (17% vs 11% vs 6%, respectively), autoimmune disease (13% vs 7% vs 9%, respectively), and nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity (9% vs 5% vs 2%, respectively) and the highest disease impact. The W patients, compared with W+AE and AE patients, showed the lowest rates of concomitant hypertension (15% vs 21% vs 40%, respectively) and obesity (11% vs 16% vs 17%, respectively), the highest rate of concomitant inducible urticaria (24% vs 22% vs 6%, respectively), and shorter W duration. The AE patients, compared with W+AE and W patients, were older at disease onset, showed longer AE duration, and the best response to increased doses of H1-antihistamines (58% vs 24% vs 31%, respectively) and omalizumab (92% vs 67% vs 60%, respectively).

CONCLUSIONS

Our findings provide a better understanding of CSU phenotypes and may guide patient care and research efforts that aim to link them to pathogenic drivers.

Differential diagnosis between urticarial vasculitis and chronic spontaneous urticaria: An international Delphi survey

BACKGROUND

Urticarial vasculitis (UV) should be differentiated from chronic spontaneous urticaria (CSU) in patients initially presenting with recurrent wheals, although criteria for differential diagnosis remain ill-defined.

OBJECTIVES

To set the goals, define criteria and unmet needs in UV diagnosis and differential diagnosis with CSU, and explore the possibility of coexistence of both diseases.

METHODS

Thirteen experts experienced in UV research participated in a Delphi survey of European Academy of Allergy and Clinical Immunology taskforce. This Delphi survey involved three rounds of anonymous responses to n = 32 questions with the aim to aggregate the experts' opinions and to achieve consensus. Urticaria specialists (n = 130, most from Urticaria Centers of Reference and Excellence) evaluated the consensus statements and recommendations in the fourth and final round.

RESULTS

The panel agreed that essential criteria to guide a skin biopsy in patients with recurrent wheals should include at least one of the following features: wheal duration >24 h, bruising/postinflammatory hyperpigmentation, and systemic symptoms. Leukocytoclasia and fibrin deposits were identified as a minimum set of UV histological criteria. As agreed by the panel members, CSU and normocomplementemic UV (NUV) may coexist in some patients.

CONCLUSIONS

The use of established criteria for the diagnosis and differential diagnosis of UV in patients with recurrent wheals can help guide the diagnostic approach and prompt earlier treatment. Further studies should investigate whether CSU and NUV are different entities or part of a disease spectrum.

The Benefit of Complete Response to Treatment in Patients With Chronic Spontaneous Urticaria-CURE Results

BACKGROUND AND OBJECTIVE

Chronic spontaneous urticaria (CSU) is a distressing disease. We report real-world data from the global Chronic Urticaria Registry (CURE) about associations between various CSU states and sleep impairment, plus important health-related quality-of-life (HRQoL) outcomes and compared different methods to assess CSU states.

METHODS

CURE data were collected at baseline and 6-monthly follow-ups (FU). Assessments included CSU states using the Urticaria Control Test (UCT), weekly Urticaria Activity Score (UAS7), and Physician Global Assessment (PhyGA) of treatment response. Complete response to treatment (CR, UAS7 = 0), complete control of disease (CC, UCT = 16), and PhyGA = CR were assessed, plus the Dermatology Life Quality Index and the Chronic Urticaria Quality-of-Life Questionnaire (CU-Q₂oL) sleep domain.

RESULTS

Overall, 2078 patients were included. At baseline, 9.8%, 17.9%, and 42.3% of patients had UCT = 16, UAS7 = 0, or PhyGA = CR, respectively, which increased at FU1 and FU2. Patients with higher UCT scores had better sleep and HRQoL. The presence of angioedema without wheals, episodic disease, omalizumab treatment, and male sex were associated with CC (P < .05). Among 469 patients who achieved CC or CR, 16.4% (n = 77) showed CC or CR with all 3 instruments. Agreement between UCT = 16 and UAS7 = 0 measurements was moderate (κ = 0.581), but poor between UCT = 16 and PhyGA = CR (κ = 0.208).

CONCLUSIONS

Few patients had CR/CC of their CSU at baseline entry. Disease control strongly related to good sleep and better HRQoL; therefore, it is important to aim for CR in CSU treatment. Patient-reported UCT and UAS7 assessments demonstrated a more accurate measurement of CSU state versus physician assessments.

Urticaria

Urticaria is an inflammatory skin disorder that affects up to 20% of the world population at some point during their life. It presents with wheals, angioedema or both due to activation and degranulation of skin mast cells and the release of histamine and other mediators. Most cases of urticaria are acute urticaria, which lasts ≤6 weeks and can be associated with infections or intake of drugs or foods. Chronic urticaria (CU) is either spontaneous or inducible, lasts >6 weeks and persists for >1 year in most patients. CU greatly affects patient quality of life, and is linked to psychiatric comorbidities and high healthcare costs. In contrast to chronic spontaneous urticaria (CSU), chronic inducible urticaria (CIndU) has definite and subtype-specific triggers that induce signs and symptoms. The pathogenesis of CSU consists of several interlinked events involving autoantibodies, complement and coagulation. The diagnosis of urticaria is clinical, but several tests can be performed to exclude differential diagnoses and identify underlying causes in CSU or triggers in CIndU. Current urticaria treatment aims at complete response, with a stepwise approach using second-generation H1 antihistamines, omalizumab and cyclosporine. Novel treatment approaches centre on targeting mediators, signalling pathways and receptors of mast cells and other immune cells. Further research should focus on defining disease endotypes and their biomarkers, identifying new treatment targets and developing improved therapies.

Pathobiology of Second-Generation Antihistamines Related to Sleep in Urticaria Patients

Background: Standard treatment options for urticaria are second-generation antihistamines; however, their effect on sleep is uncertain. This study measures the influence of different antihistamines on the biologic sleep pattern of urticaria patients and the relevance of sleep in urticaria patients. Methods: Ten patients with chronic spontaneous urticaria (CSU) and uncontrolled symptoms under a single dose of second-generation antihistamines were included. Two nights were monitored: the first night after 5 days on single dosage and the second night after 5 days on fourfold dosage. Patient-rated questionnaires were used and sleep was monitored using polygraphy. Results: The patients’ rated daytime sleepiness decreased (p = 0.0319), as did their insomnia severity (p = 0.0349). The urticaria control (UCT) improved (p = 0.0007), as did the quality of life (p < 0.0001). There was no significant change of nightly pruritus (p = 0.1173), but there was an improvement of daytime pruritus (p = 0.0120). A significant increase in rapid eye movement (REM) sleep was seen (p = 0.0002) (from a mean of 3.9% to 14.3%). The deep sleep state (N3) also improved (8.7% to 12.3%) (p = 0.1172). Conclusion: This study has demonstrated an improvement of the sleep pattern in CSU patients under up-dosed second-generation antihistamines, without increased daytime sleepiness, alongside an improvement of urticaria symptoms and quality of life.

EAACI Biologicals Guidelines-Omalizumab for the treatment of chronic spontaneous urticaria in adults and in the paediatric population 12-17 years old

Chronic spontaneous urticaria (CSU) imposes a significant burden on patients, families and healthcare systems. Management is difficult, due to disease heterogeneity and insufficient efficacy of classical drugs such as H₁ R-antihistamines. Better understanding of the mechanisms has enabled a stratified approach to the management of CSU, supporting the use of targeted treatment with omalizumab. However, many practical issues including selection of responders, the definition of response, strategies to enhance the responder rate, the duration of treatment and its regimen (in the clinic or home-based) and its cost-effectiveness still require further clarification. The EAACI Guidelines on the use of omalizumab in CSU follow the GRADE approach in formulating recommendations for each outcome. In addition, future therapeutic approaches and perspectives as well as research priorities are discussed.