Non-Skin-Related Symptoms are Common in Chronic Spontaneous Urticaria and Linked to Active and Uncontrolled Disease: Results from CURE.

BACKGROUND: Chronic spontaneous urticaria (CSU) can present with non-skin-related symptoms (NSRS), including recurrent unexplained fever, joint/bone/muscle pain (JBMP), and malaise, which also occur in other conditions that manifest with wheals (e.g., urticarial vasculitis or autoinflammatory disorders) or without wheals (e.g., 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 (CURE) of 2,521 patients with CSU who were ≥16 years old. RESULTS: One-third of CSU patients (31.2%, 786/2,521) had ≥1 NSRS, including recurrent fever (5.3%), JBMP (19.1%), and/or malaise (18.6%). In a multivariable analysis, having ≥1 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 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 (UAS7, median: 21 vs. 14, p=0.009), longer disease duration (years, median: 2 vs. 1, p=0.001), presence of angioedema (74.6% vs. 58.7%, p<0.001), worse quality of life (CU-Q2oL, median: 42 vs. 29, p<0.001) and more frequent poor control of CSU (78% vs. 69%, p<0.001). CONCLUSION: The presence of NSRS in a subpopulation of CSU patients points to a need for better control of the disease, exclusion of comorbid conditions and/or exclusion of urticarial vasculitis and urticarial autoinflammatory diseases.

A global perspective on stepping down chronic spontaneous urticaria treatment: Results of the Urticaria Centers of Reference and Excellence SDown-CSU study.

BACKGROUND: Although there have been significant advances in the treatment of chronic spontaneous urticaria (CSU) in recent years, there remains a lack of clear guidance on when and how to step down treatment in responders. This study aims to investigate stepping down approaches of different steps of CSU treatment from a global perspective. METHODS: "Stepping down chronic spontaneous urticaria treatment" (SDown-CSU) is an international, multicenter, observational, cross-sectional, survey-based study of the Urticaria Centers of Reference and Excellence (UCARE) network. The questionnaire included 48 questions completed by physicians in the UCARE network. RESULTS: Surveys completed by 103 physicians from 81 UCAREs and 34 countries were analyzed. Seventy-eight percent of the participants responded that they had a national urticaria management guideline written by their professional societies and 28% responded that they had to operate under a regulatory guideline proposed by central health funding organizations. Seventy-two and 58.7% of these national recommendations do not contain any detailed information on when and/or how CSU treatment should be discontinued. There was a lack of detailed information on antihistamines and cyclosporine in particular. A predefined maximum duration was generally not applicable to omalizumab and cyclosporine (81% and 82%, respectively). Nearly all UCAREs step down omalizumab within 6 months from the first controlled status and 42% discontinue cyclosporine after 6 months regardless of the control status. CONCLUSIONS: The findings from the SDown-CSU study clearly highlight a global need for guidance on the process of stepping down treatment in CSU. Additionally, the study offers a step-down algorithm applicable to all stages of CSU treatment.

Challenges in the Diagnosis of Cutaneous Mastocytosis.

BACKGROUND: Mastocytosis is characterized by an accumulation of clonal mast cells (MCs) in tissues such as the skin. Skin lesions in mastocytosis may be clinically subtle or heterogeneous, and giving the correct diagnosis can be difficult. METHODS: This study compiles personal experiences together with relevant literature, discussing possible obstacles encountered in diagnosing skin involvement in mastocytosis and cutaneous mastocytosis (CM). RESULTS: The nomenclature of the term "CM" is ambiguous. The WHO classification defines CM as mastocytosis solely present in the skin. However, the term is also used as a morphological description, e.g., in maculopapular cutaneous mastocytosis (MPCM). This is often seen in systemic, as well as cutaneous, mastocytosis. Typical CM manifestations (MPCM), including mastocytoma or diffuse cutaneous mastocytosis (DCM), all share a positive Darier's sign, and can thus be clinically recognized. Nevertheless, distinguishing monomorphic versus polymorphic MPCM may be challenging, even for experienced dermatologists. Less typical clinical presentations, such as MPCM with telangiectatic erythemas (formerly called telangiectasia macularis eruptiva perstans), confluent, nodular or xanthelasmoid variants may require a skin biopsy for histopathological confirmation. Because MC numbers in CM have a large overlap to those in healthy and inflamed skin, detailed histopathological criteria to diagnose mastocytosis in MPCM are needed and have been proposed. D816V KIT mutational analysis in tissue is helpful for confirming the diagnosis. Biomarkers allow the prediction of the course of CM into regression or evolution of the disease. Further diagnostic measures should screen for concomitant diseases, such as malignant melanoma, and for systemic involvement. CONCLUSIONS: Whereas in typical cases the diagnosis of CM may be uncomplicated, less typical manifestations may require specific investigations for making the diagnosis and predicting its course.

Efficacy and safety of ligelizumab in adults and adolescents with chronic spontaneous urticaria: results of two phase 3 randomised controlled trials.

BACKGROUND: Many patients with chronic spontaneous urticaria (CSU) do not achieve complete control of their symptoms with current available treatments. In a dose-finding phase 2b study, ligelizumab improved urticaria symptoms in patients with H1-antihistamine (H1-AH) refractory CSU. Here, we report the efficacy and safety outcomes from two ligelizumab phase 3 studies. METHODS: PEARL-1 and PEARL-2 were identically designed randomised, double-blind, active-controlled and placebo-controlled parallel-group studies. Patients aged 12 years or older with moderate-to-severe H1-AH refractory CSU were recruited from 347 sites in 46 countries and randomly allocated in a 3:3:3:1 ratio via Interactive Response Technology to 72 mg ligelizumab, 120 mg ligelizumab, 300 mg omalizumab, or placebo, dosed every 4 weeks, for 52 weeks. Patients allocated to placebo received 120 mg ligelizumab from week 24. The primary endpoint was change-from-baseline (CFB) in weekly Urticaria Activity Score (UAS7) at week 12, and was analysed in all eligible adult patients according to the treatment assigned at random allocation. Safety was assessed throughout the study in all patients who received at least one dose of the study drug. The studies were registered with ClinicalTrials.gov, NCT03580369 (PEARL-1) and NCT03580356 (PEARL-2). Both trials are now complete. FINDINGS: Between Oct 17, 2018, and Oct 26, 2021, 2057 adult patients were randomly allocated across both studies (72 mg ligelizumab n=614; 120 mg ligelizumab n=616; 300 mg omalizumab n=618, and placebo n=209). A total of 1480 (72%) of 2057 were female, and 577 (28%) of 2057 were male. Mean UAS7 at baseline across study groups ranged from 29·37 to 31·10. At week 12, estimated treatment differences in mean CFB-UAS7 were as follows: for 72 mg ligelizumab versus placebo, -8·0 (95% CI -10·6 to -5·4; PEARL-1), -10·0 (-12·6 to -7·4; PEARL-2); 72 mg ligelizumab versus omalizumab 0·7 (-1·2 to 2·5; PEARL-1), 0·4 (-1·4 to 2·2; PEARL-2); 120 mg ligelizumab versus placebo -8·0 (-10·5 to -5·4; PEARL-1), -11·1 (-13·7 to -8·5; PEARL-2); 120 mg ligelizumab versus omalizumab 0·7 (-1·1 to 2·5; PEARL-1), -0·7 (-2·5 to 1·1; PEARL-2). Both doses of ligelizumab were superior to placebo (p<0·0001), but not to omalizumab, in both studies. No new safety signals were identified for ligelizumab or omalizumab. INTERPRETATION: In the phase 3 PEARL studies, ligelizumab demonstrated superior efficacy versus placebo but not versus omalizumab. The safety profile of ligelizumab was consistent with previous studies. FUNDING: Novartis Pharma.

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.

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.

How Infection and Vaccination Are Linked to Acute and Chronic Urticaria: A Special Focus on COVID-19.

Since more than a century ago, there has been awareness of the connection between viral infections and the onset and exacerbation of urticaria. Our knowledge about the role of viral infection and vaccination in acute and chronic urticaria improved as a result of the COVID-19 pandemic but it has also highlighted knowledge gaps. Viral infections, especially respiratory tract infections like COVID-19, can trigger the onset of acute urticaria (AU) and the exacerbation of chronic urticaria (CU). Less frequently, vaccination against viruses including SARS-CoV-2 can also lead to new onset urticaria as well as worsening of CU in minority. Here, with a particular focus on COVID-19, we review what is known about the role of viral infections and vaccinations as triggers and causes of acute and chronic urticaria. We also discuss possible mechanistic pathways and outline the unmet needs in our knowledge. Although the underlying mechanisms are not clearly understood, it is believed that viral signals, medications, and stress can activate skin mast cells (MCs). Further studies are needed to fully understand the relevance of viral infections and vaccinations in acute and chronic urticaria and to better clarify causal pathways.

European Competence Network on Mastocytosis (ECNM): 20-Year Jubilee, Updates, and Future Perspectives.

In 2002, the European Competence Network on Mastocytosis (ECNM) was launched as a multidisciplinary collaborative initiative to increase the awareness and to improve diagnosis and management of patients with mast cell (MC) disorders. The ECNM consists of a net of specialized centers, expert physicians, and scientists who dedicate their work to MC diseases. One essential aim of the ECNM is to timely distribute all available information about the disease to patients, doctors, and scientists. In the past 20 years, the ECNM has expanded substantially and contributed successfully to the development of new diagnostic concepts, and to the classification, prognostication, and treatments of patients with mastocytosis and MC activation disorders. The ECNM also organized annual meetings and several working conferences, thereby supporting the development of the World Health Organization classification between 2002 and 2022. In addition, the ECNM established a robust and rapidly expanding patient registry and supported the development of new prognostic scoring systems and new treatment approaches. In all projects, ECNM representatives collaborated closely with their U.S. colleagues, various patient organizations, and other scientific networks. Finally, ECNM members have started several collaborations with industrial partners, leading to the preclinical development and clinical testing of KIT-targeting drugs in systemic mastocytosis, and some of these drugs received licensing approval in recent years. All these networking activities and collaborations have strengthened the ECNM and supported our efforts to increase awareness of MC disorders and to improve diagnosis, prognostication, and therapy in patients.

Physical urticaria: Clinical features, pathogenesis, diagnostic work-up, and management.

Physical urticaria is a type of urticaria in which recurrent wheals and/or angioedema occur following exposure of the skin to a physical stimulus. It is classified according to its triggers, which may be mechanical (friction, pressure, and vibration), thermal (cold and heat), or solar electromagnetic radiation. Symptoms of different physical urticarias can develop following specific activities that expose patients to an eliciting stimulus and may be variably accompanied by mucosal involvement and systemic symptoms, including nausea, headache, or even anaphylaxis. Differentiation of physical urticaria from other chronic urticarias requires careful clinical assessment and confirmatory provocation testing, which in turn can inform appropriate management. This clinical review provides an evidence-based summary of the epidemiology, clinical features, pathogenesis, diagnostic work-up, and management of physical urticaria.

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.

Pharmacokinetic equivalence of CT-P39 and reference omalizumab in healthy individuals: A randomised, double-blind, parallel-group, Phase 1 trial.

BACKGROUND: CT-P39 is being developed as a biosimilar of reference omalizumab. This study aimed to assess the pharmacokinetic equivalence of CT-P39 to European Union-approved and United States-licensed reference omalizumab (EU- and US-omalizumab, respectively). METHODS: This two-part, randomised, parallel-group, double-blind Phase 1 trial (NCT04018313) was conducted in healthy individuals with a total immunoglobulin E (IgE) level ≤100  international units (IU)/ml at screening. In part 2, described herein, participants were randomised (1:1:1) to receive a single 150 mg subcutaneous dose of CT-P39, EU-omalizumab, or US-omalizumab. The primary endpoint was pharmacokinetic equivalence in terms of area under the concentration-time curve (AUC) from time zero to the last quantifiable concentration (AUC0-last ), AUC from time zero to infinity (AUC0-inf ), and maximum serum concentration (Cmax ). Equivalence was concluded if 90% confidence intervals (CIs) of the geometric least-squares means ratios were contained within the predefined 80%-125% equivalence margin. Additional pharmacokinetic parameters, pharmacodynamics, safety, and immunogenicity were also evaluated. RESULTS: Overall, 146 participants were randomised (CT-P39, N = 47; EU-omalizumab, N = 49; US-omalizumab, N = 50). For all primary pharmacokinetic parameters, 90% CIs for pairwise treatment comparisons were within the 80%-125% equivalence margin, demonstrating pharmacokinetic equivalence. Decreases in free IgE and increases in total IgE serum concentrations were comparable across groups. CT-P39 was well tolerated. Safety endpoints were comparable across groups: there were no treatment-related serious adverse events, deaths, or discontinuations due to treatment-emergent adverse events. CONCLUSIONS: CT-P39 was well tolerated and demonstrated pharmacokinetic equivalence with EU-omalizumab and US-omalizumab following administration of a single dose in healthy individuals.

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.

Adherence to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist in articles published in EAACI Journals: A bibliographic study.

Research data derived from observational studies are accumulating quickly in the field of allergy and immunology and a large amount of observational studies are published every year. The aim of the present study was to evaluate the adherence to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist by papers published in the three European Academy of Allergy and Clinical Immunology journals, during the period 2009-2018. To this end, we conducted a bibliographic study of up to eight randomly selected papers per year per Journal. Our literature search resulted in 223 papers. Amongst those, 80, 80 and 63 records were from Paediatric Allergy and Immunology, Allergy and Clinical and Translational Allergy, respectively; the latter was published only from 2011 on. Prospective, case control and cross-sectional designs were described in 88, 43 and 92 papers, respectively. Full reporting of all STROBE items was present in 47.4%, 45.6% and 41.2% for the cohort, cross-sectional and case-control studies, respectively. Generally, no time trend in adherence of reporting STROBE items was observed, apart from reporting funding, which increased from 60% in 2009/2010 to more than 90% in 2018. We identified a cluster of STROBE items with low proportions of full reporting constituted by the items on reporting study design in the title and methods, variables types along with their measurement/assessment, bias and confounding, study size, and grouping of variables. It appears that the STROBE checklist is a suitable tool in observational allergy epidemiology. However, adherence to the STROBE checklist appeared suboptimal.

Effects of a topical treatment with spleen tyrosine kinase inhibitor in healthy subjects and patients with cold urticaria or chronic spontaneous urticaria: Results of a phase 1a/b randomised double-blind placebo-controlled study.

AIMS: To explore the safety, tolerability, pharmacokinetics and pharmacodynamics (PD) of GSK2646264 using skin challenge models. METHODS: Healthy volunteers (HV) with a positive allergen skin prick test received GSK2646264 (0.5% or 1% ww) and placebo creams on up to 10% body surface area (BSA). Cold (ColdU) or chronic spontaneous (CSU) urticaria patients received 1% GSK2646264 or placebo on up to 10% BSA. PD assessments included weal characteristics after skin allergen challenge, critical temperature threshold (CTT) in ColdU patients and defined area urticaria activity score in CSU patients. RESULTS: Thirty-four patients were randomised (17 HV, 12 ColdU, 5 CSU). Topical application of GSK2646264 and placebo was well tolerated. Systemic pharmacokinetics (AUC [0-24] h*ng/mL) was similar between HVs (Geomean 97.9 [%CV 37]) and ColdU patients (Geomean 68.2 [%CV 14; 3.5% BSA] or 167 [%CV 120; 10% BSA]). Whilst in HVs a similar reduction in skin allergen challenge weal area was observed following 3 applications of GSK2646264 and placebo, a trend towards a greater reduction was seen in ColdU with GSK2646264 compared to placebo. A clinically meaningful reduction in CTT, in ColdU patients treated with GSK2646264, was observed in 4 of 9 patients, who demonstrated either a complete inhibition of ColdU to ≤4°C (n = 2) or partial response (reduction by >4°C, n = 2). Due to the small number of CSU patients recruited, no meaningful conclusions could be drawn from the defined area urticaria activity score PD endpoint. CONCLUSION: This Phase 1/1b study confirms that GSK2646264 cream applied topically penetrates the skin and some reduction in CTT was observed. (NCT02424799).

COVID-19 Vaccination in Mastocytosis: Recommendations of the European Competence Network on Mastocytosis (ECNM) and American Initiative in Mast Cell Diseases (AIM).

Mastocytosis is a neoplasm characterized by an accumulation of mast cells in various organs and increased risk for severe anaphylaxis in patients with concomitant allergies. Coronavirus disease 2019 (COVID-19) is a pandemic that is associated with a relatively high rate of severe lung disease and mortality. The mortality is particularly high in those with certain comorbidities and increases with age. Recently, several companies have developed an effective vaccination against COVID-19. Although the reported frequency of severe side effects is low, there is an emerging discussion about the safety of COVID-19 vaccination in patients with severe allergies and mastocytosis. However, even in these patients, severe adverse reactions are rare. We therefore recommend the broad use of COVID-19 vaccination in patients with mastocytosis on a global basis. The only well-established exception is a known or suspected allergy against a constituent of the vaccine. Safety measures, including premedication and postvaccination observation, should be considered in all patients with mastocytosis, depending on the individual personal risk and overall situation in each case. The current article provides a summary of published data, observations, and expert opinion that form the basis of these recommendations.

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.

Hereditary Alpha-Tryptasemia: UK Prevalence and Variability in Disease Expression.

BACKGROUND: Hereditary alpha-tryptasemia (HAT) is a genetic trait caused by an increased alpha-tryptase tryptase alpha/beta 1 gene copy number. Basal serum mast cell tryptase (MCT) level is typically greater than or equal to 8.0 ng/mL. OBJECTIVES: To study the clinical disease spectrum of HAT and determine its UK prevalence. METHODS: Droplet digital PCR was used to determine tryptase alpha/beta 1 copy number in 432 DNA samples from an unselected UK birth cohort and in 70 patients referred with a basal MCT level greater than 8 ng/mL. Baseline MCT concentrations and clinical presentation were also assessed in 4283 samples sent to a regional immunology laboratory. RESULTS: Duplication in alpha copy number was present in 5% of the unselected British birth cohort, with all affected individuals having a basal MCT level of greater than or equal to 8.0 ng/mL. Basal MCT levels of greater than or equal to 8.0 ng/mL were also found in 5% of the 4283 individuals referred for MCT testing because of clinical symptoms. In 70 patients confirmed to have HAT (79% with a duplication; 21% with a higher alpha gene copy number), urticaria/angioedema (51%), skin flushing (41%), food intolerances (39%), and altered bowel habits (36%) were common presenting complaints. However, clinical manifestations were not more common in patients with gene triplications or quintuplications than in those with duplications. Some immediate family members with the same genetic trait and high basal MCT levels were asymptomatic. CONCLUSIONS: Five percent of people in the United Kingdom may have HAT. The diagnosis should be considered when basal MCT level is greater than or equal to 8 ng/mL. HAT has variable clinical penetrance. It may modify the expression of multifactorial allergic diseases rather than directly cause specific phenotypes.