Effectiveness and safety of antihistamines up to fourfold or higher in treatment of chronic spontaneous urticaria

Chronic Spontaneous Urticaria: An Update on the Evaluation and Management

Chronic spontaneous urticaria (CSU) affects 0.5% to 1% of the general population and is often managed by allergy and immunology specialists. Guidelines have evolved over the past several decades with an emphasis on decreasing extensive screening laboratory testing as they are of low-yield and cost-ineffective. The utility of biomarkers remains under investigation but total immunoglobulin E may be helpful in determining specific endotypes and response to omalizumab. Antihistamines and omalizumab remain the primary therapeutic options for CSU, but an expanding body of evidence supports the use of immunosuppressants and anti-inflammatory medications in refractory cases.

Predictive model to differentiate chronic histaminergic angioedema and chronic spontaneous urticaria with angioedema

Background

Chronic histaminergic angioedema (CHA) may be classified as a separate acquired angioedema (AE) or as an endotype of chronic spontaneous urticaria (CSU). A recent study suggested them to be independent pathologies.

Objective

We carried out an exhaustive analysis between CHA and AE-CSU to explore the possible differentiation between them on the bases of a series of predictors.

Methods

An observational, retrospective, cross-sectional, and exploratory study was designed. Fifty-six CHA and 40 AE-CSU patients were included. Data were extracted from the year before and year after time of diagnosis. A predictive model was generated by logistic regression, and its discriminatory power was assessed using the area under the receiver operating characteristic curve.

Results

The average frequency of AE attacks per year turned out to be higher in the AE-CSU group than in the CHA group, both before (median [interquartile range] 12 [43] vs 8 [16]) and after (24.3 [51.2] vs 2 [4.25]) diagnosis, respectively. The uvula was more frequently affected in CHA. No other differences were found. However, using 7 clinical characteristics of the patients, a multiple logistic regression model was able to predict, with a specificity of 86.4%, a sensitivity of 92.3%, and an area under the curve of 95.1% (P = .024), that CHA and AE-CSU behaved differently.

Conclusion

CHA has similar characteristics to AE-CSU, although they slightly differed in the frequency of attacks and their location. Despite its similarities, a multiple logistic regression model that used clinical and evolutionary characteristics allowed the differentiation of both pathologies and supports the idea that these 2 entities are independent.

Evaluating the efficacy of a premedication regimen including high-dose cetirizine in reduction of hypersensitivity reactions to paclitaxel: A retrospective cohort study

INTRODUCTION

Hypersensitivity reactions (HSR) are a known adverse effect of paclitaxel, occurring in approximately 10% of patients, typically during the first or second infusion of the medication. Corticosteroids, histamine-1 and histamine-2 receptor antagonists are given prior to paclitaxel infusions to reduce the incidence of HSR. There are limited data that suggest administration of cetirizine given prior to a platinum infusion as secondary prophylaxis may reduce HSR rates.

METHODS

The objective of this study was to assess the impact of a novel paclitaxel hypersensitivity prevention protocol including high-dose cetirizine administered 12 and 6 h prior to paclitaxel infusion on the rate of HSR compared to a historical control. The primary objective was the rate of HSR of any grade after the first cycle of paclitaxel. Secondary outcomes included grade of infusion reaction and incidence of severe HSR.

RESULTS

A total of 104 patients were included for analysis in the cetirizine group and 124 in the control group. Hypersensitivity reactions occurred in 37 (16.2%) patients in the overall population, and no statistical difference was observed between groups. (13.46% vs 18.55%; p = 0.23). Numerically more grade 3-4 HSRs occurred in the control group than the treatment group (30.77% vs 69.23; p = 0.51).

CONCLUSIONS

The addition of cetirizine to paclitaxel infusions resulted in numerically lower rates of HSR and a reduction in severity of grade 3-4 HSRs. Future studies with more robust compliance data and a larger patient population would be needed to appropriately assess the efficacy of our novel treatment regimen.

The future of targeted therapy in chronic spontaneous urticaria

Chronic urticaria can be divided into 2 subsets: chronic spontaneous urticaria (CSU) with skin lesions occurring without a specific trigger and chronic inducible urticaria, which has an identified specific stimulus. The annual prevalence of chronic urticaria is 0.5% to 2.3% globally. The CSU is a self-limited disorder in most cases, with an average duration of 2 to 5 years, but symptoms persist beyond 5 years in up to 30% of patients. The first line of treatment is a daily nonsedating, second-generation H1-antihistamine. The CSU guidelines recommend using oral nonsedating antihistamines up to 4 fold in patients with CSU unresponsive to standard doses as the next step in treatment. A meta-analysis found that the rate of response in patients with CSU who responded to updosing was 63.2%. Therefore, approximately 40% of patients continue to have persistent hives and itching requiring treatment with the biologic omalizumab, based on evidence from randomized controlled trials. Although omalizumab has been shown to markedly relieve symptoms of CSU, omalizumab is not effective in all patients and has not been shown to induce long-term disease remission. Thus, there is an unmet need for more effective treatments that can lead to cure or long-term remission. In this review, we will provide an overview of new treatment targets and biologics that are under investigation for the treatment of CSU.

A Practical Approach to Diagnosing and Managing Chronic Spontaneous Urticaria

Chronic spontaneous urticaria (CSU) is an unpredictable inflammatory skin condition characterized by the spontaneous onset of itchy wheals, angioedema, or both, which occurs for longer than 6 weeks overall. Despite the relatively straightforward diagnostic algorithm for CSU, relying primarily on a detailed medical history and only limited laboratory tests, patients often wait years to be diagnosed, with many cycling through different healthcare practitioners before a diagnosis is made. Even then, current treatment options for CSU are limited, with approximately half of patients resistant to standard-of-care second-generation antihistamines at standard or higher doses. As such, there is an unmet need for improved, streamlined management for patients with CSU. Here, we review the evidence-based diagnostic algorithm for CSU, consider the required steps of the diagnostic workup, and provide practical, real-world advice on the management of CSU to improve the timely diagnosis and care of patients with this debilitating disease.

A Prospective Randomized Non-Blinded Study of Safety and Efficacy of Bilastine Up-Dosing (40 mg) Versus Combination of Bilastine 20 mg With Levocetirizine 5 mg in the Treatment of Chronic Spontaneous Urticaria

Introduction

Chronic spontaneous urticaria (CSU) is the most commonly diagnosed skin condition in dermatology outpatient departments. Second-generation antihistamines are shown to be effective in the control of CSU. As per the guidelines, a combination of antihistamines is less recommended due to the lack of synergistic effect, though used widely. Exploring effective treatment options are crucial, given the challenges posed by CSU.

Aims and Objectives

To assess the safety and efficacy of Bilastine up-dosing versus combination of 20 mg Bilastine with 5 mg Levocetirizine in the treatment of CSU.

Materials and Methods

This prospective randomized non-blinded comparative trial involved 62 patients, with 32 in group A and 30 in group B. Group A received Tablet Bilastine 20 mg bd, while Group B received a combination of Tablet Bilastine 20 mg and Tablet Levocetirizine 5 mg. Urticarial Activity Score 7 was performed at baseline and follow-up visits (every 2 weeks for 6 weeks).

Results

Both groups had a higher number of male patients in the 20-30 years age group. Angioedema was present in 15.6% of group A and 23.3% in group B. After 6 weeks, both the groups showed a significant improvement in UAS 7 scores (P value <0.05). Group A demonstrated a remarkable reduction in UAS 7 from 19.4% to 0.03% with minimal side effects.

Conclusion

Bilastine up-dosing proved to be efficient, secure, and well tolerated when compared to the combined dose of Levocetirizine 5 mg and Bilastine 20 mg, suggesting that up-dosing of Bilastine could be a valuable addition to the current medication arsenal with the minimal side effects.

An update on the use of antihistamines in managing chronic urticaria

INTRODUCTION

Urticaria, a mast cell-mediated skin disease, manifests as acute or chronic, with the latter divided into spontaneous and inducible types and requires individualized management, including identifying triggers and comorbidities. Antihistamines, particularly the second generation group, form the mainstay of primary treatment plans consisting of dosage adjustments and/or in combination with other treatment modalities depending on underlying disease control.

AREAS COVERED

A literature search was conducted using 'antihistamines,' 'urticaria,' 'pharmacogenomics,' 'genomics,' 'biomarkers' and 'treatment response' as key words. In this review, we focus on the comprehensive understanding and application of antihistamines in managing adult and adolescent patients with chronic urticaria.

EXPERT OPINION

Using antihistamines to treat urticaria is set to change significantly, focusing more on personalized medicine and identifying key biomarkers to enhance treatment response prediction. These changes aim to make treatments more specific and cost-effective by avoiding unnecessary tests. Applying new approaches in everyday clinical care faces challenges like proving the biomarkers' reliability, updating current guidelines, and incorporating individualized treatments into standard procedures. Efforts should now concentrate on finding easy-to-use biomarkers, improving access to pharmacogenomics, understanding why some patients are resistant to treatment, and creating more specific treatment options based on patient needs.

Managing hyperglycemia and rash associated with alpelisib: expert consensus recommendations using the Delphi technique

Hyperglycemia and rash are expected but challenging adverse events of phosphatidylinositol-3-kinase inhibition (such as with alpelisib). Two modified Delphi panels were conducted to provide consensus recommendations for managing hyperglycemia and rash in patients taking alpelisib. Experts rated the appropriateness of interventions on a 1-to-9 scale; median scores and dispersion were used to classify the levels of agreement. Per the hyperglycemia panel, it is appropriate to start alpelisib in patients with HbA1c 6.5% (diabetes) to <8%, or at highest risk for developing hyperglycemia, if they have a pre-treatment endocrinology consult. Recommend prophylactic metformin in patients with baseline HbA1c 5.7% to 6.4%. Metformin is the preferred first-line anti-hyperglycemic agent. Per the rash panel, initiate prophylactic nonsedating H1 antihistamines in patients starting alpelisib. Nonsedating H1 antihistamines and topical steroids are the preferred initial management for rash. In addition to clinical trial evidence, these recommendations will help address gaps encountered in clinical practice.

Effect of second-generation antihistamines on nighttime sleep and daytime sleepiness in patients with allergic rhinitis

BACKGROUND

The daytime tiredness experienced by the vast majority of allergic rhinitis (AR) sufferers is directly related to the fact that they experience disrupted sleep at night. This study compared the effects of recently marketed second-generation H1 antihistamines (SGAs) on nighttime sleep and daytime sleepiness in patients with AR, with patients grouped into those taking non-brain-penetrating antihistamines (NBP group) and those taking brain-penetrating antihistamines (BP group).

METHODS

Patients with AR completed self-administered questionnaire-based surveys to determine Pittsburgh Sleep Quality Index (PSQI) before and after taking SGAs. Statistical analysis was performed on each evaluation item.

RESULTS

Of 53 Japanese patients with AR between 6 and 78 years old, median (SD) age was 37.0 (22.4) years old and 21 were men (40%). Of the 53 patients, 34 were the NBP group and 19 were the BP group. In the NBP group, mean (SD) subjective sleep quality score after medication was 0.76 (0.50), which was significantly lower (better) than the score of 0.97 (0.52) before medication (p = 0.020). In the BP group, mean (SD) subjective sleep quality score after medication was 0.79 (0.54), which was not significantly different from the score of 0.74 (0.56) before medication (p = 0.564). In the NBP group, mean (SD) global PSQI score was 3.47 (1.71) after medication, which was significantly lower (better) than the score of 4.35 (1.92) before medication (p = 0.011). In the BP group, mean (SD) global PSQI score was 2.47 (2.39) after medication, which was not significantly different from the score of 3.00 (2.71) before medication (p = 0.125).

CONCLUSION

Subjective sleep quality and global PSQI score were improved only in the group taking non-brain-penetrating SGAs.

Evidence-based use of antihistamines for treatment of allergic conditions

Available since the 1940s, H1 antihistamines are mainstay treatments for allergic conditions such as allergic rhinitis and urticaria. They function as inverse agonists that bind to the H1 receptor to inhibit histamine-induced inflammation. The older, first-generation drugs are no longer recommended for patient use because of their well-documented negative adverse effect profile. Evidence has been accumulating to support a newer generation of H1 antihistamines in oral and intranasal formulations, including in combination with intranasal corticosteroids. The literature is replete with large meta-analyses and systematic reviews establishing the safety and efficacy of second-generation H1 antihistamines in adult and pediatric allergic rhinitis populations, including combination nasal spray agents (eg, MP29-02 or MP-AzeFlu). Although intraclass differences do exist, patient preference, access, and costs should be the priority. Robust data on the regular, not as needed use of H1 antihistamines for urticaria have been published, including in the management of children and pregnant or lactating women. In addition, H1 antihistamines can be used in other related allergic conditions, such as the secondary symptoms of anaphylaxis, to provide patients with greater comfort, including in allergic asthma, depending on the individual.

Comparative effectiveness and safety of drug therapy for chronic urticaria: a network meta-analysis and risk-benefit assessment

BACKGROUND

Chronic urticaria (CU) is a prevalent chronic skin condition characterized by recurrent wheals. Clinical guidelines recommend multiple drugs for CU treatment. Our study aims to compare the effectiveness and safety of drug therapy for CU.

METHODS

We conducted a comprehensive search of randomized controlled trials (RCTs) and real-world studies (RWSs) in PubMed, EMBASE, and Cochrane. A network meta-analysis (NMA) was conducted to assess the response rate, decline in Urticaria Activity Score over 7 Days (UAS7), Dermatology Life Quality Index (DLQI), and adverse event rates of standard-dose and high-dose H1 antihistamine (H1AH), omalizumab (OMA) 75, 150, and 300 mg, cyclosporine and placebo. The risk-benefit assessment was conducted by probabilistic simulation and stochastic multicriteria acceptability analysis (SMAA).

RESULTS

A total of 39 studies were identified, including 37 RCTs and 2 RWSs. OMA 300 mg and 150 mg both had significantly higher response rate than standard-dose H1AH (p < 0.05, respectively). OMA 300 mg and 150 mg both consistently led to a huge drop in UAS7 and DLQI compared to standard-dose H1AH and high-dose H1AH (p < 0.05).

CONCLUSION

Regarding risk-benefit assessment, OMA 300 mg emerges as the optimal pharmacological intervention for CU, while OMA 150 mg stands as a secondary alternative compared to H1 antihistamines and cyclosporine.

Clinical Response to Low-dose Omalizumab Treatment in Chronic Spontaneous Urticaria: A Retrospective Study of 179 Patients

Omalizumab is effective in chronic spontaneous urticaria unresponsive to antihistamines. Of the licensed dosing schedules, Korean patients prefer a low dose, of 150 mg/month, for financial reasons. However, real-world experiences of low-dose omalizumab consumption have not been reported. The aim of this retrospective study was to assess the treatment outcomes and long-term clinical course of patients with chronic spontaneous urticaria who were treated with low-dose omalizumab. The study included 179 patients aged ≥ 20 years who were treated with omalizumab 150 mg/month for ≥ 12 weeks. Baseline disease activity was mild, moderate, and severe in 54.7%, 35.2%, and 10.1% of patients, respectively. A complete response was observed in 133 patients at 12 weeks, among whom 88 patients showed early responses within 4 weeks. Overall, 158 patients finally achieved a complete response. Multivariate analyses revealed that baseline disease activity is more likely to be mild in patients who experience early and final complete responses. The absence of atopic comorbidities correlated with an early response. Smoking was associated with a final complete response. This study shows that low-dose omalizumab provides favourable treatment outcomes in antihistamine-refractory chronic spontaneous urticaria. Disease severity, atopic comorbidity, and smoking may be predictive factors for studying the response to omalizumab.

Chronic urticaria and the pathogenic role of mast cells

The signs and symptoms of chronic urticaria (CU) are caused by the activation and degranulation of skin mast cells (MCs). Recent studies have added to our understanding of how and why skin MCs are involved and different in CU. Also, novel and relevant mechanisms of MC activation in CU have been identified and characterized. Finally, the use of MC-targeted and MC mediator-specific treatments has helped to better define the role of the skin environment, the contribution of specific MC mediators, and the relevance of MC crosstalk with other cells in the pathogenesis of CU. Here, we review these recent findings and their impact on our understanding of CU, with a focus on chronic spontaneous urticaria (CSU). Also, we highlight open questions, issues of controversy, and unmet needs, and we suggest what studies should be performed moving forward.

Differences between adult and pediatric chronic spontaneous urticaria from a cohort of 751 patients: Clinical features, associated conditions and indicators of treatment response

BACKGROUND

Chronic spontaneous urticaria (CSU) is a common disease both in the pediatric and in the adult population. However, there are differences between the two patient populations with respect to etiological factors, comorbidities, and treatment responses. Our aim was to determine differences between pediatric and adult CSU in terms of clinical characteristics, laboratory parameters, comorbidities, response to treatment, and indicators of response.

METHODS

A retrospective analysis of CSU patients was performed. Data regarding differences between pediatric and adult CSU patients were analyzed. Indicators of treatment response were determined separately in both pediatric and adult patients.

RESULTS

Of 751 CSU patients (162 pediatrics and 589 adults), female dominancy (48.8% vs. 69.6%) and rate of angioedema (19.1% vs. 59.8%) were lower, and disease duration (5 months vs. 12 months) was shorter in pediatric patients. Anti-TPO positivity (24.7% vs. 9%), elevated CRP (46.5% vs. 11.1%), eosinopenia (38.5% vs. 18.1%), and skin prick test positivity (39.3% vs. 28.8%) were significantly more frequent in adult patients. Response to antihistamines was higher in the pediatric group, and only 7% used omalizumab versus 20.8% in the adults. The comparisons were also performed between <12-year and ≥12-year patients and yielded similar results.

CONCLUSION

Pediatric CSU shows distinct characteristics such as lower incidence of angioedema and antithyroid antibodies, and it responds better to antihistamines. These suggest that CSU becomes more severe and refractory in adolescents and adults. Adolescent CSU shows features similar to adult CSU rather than pediatric CSU.

Skin-homing basophils and beyond

Basophils have been implicated in type 2 inflammation and numerous disorders in the skin such as helminth infection, atopic dermatitis, and urticaria. Although similar in form and function to tissue-resident mast cells, classical studies on basophils have centered on those from the hematopoietic compartment. However, increasing studies in tissues like the skin demonstrate that basophils may take on particular characteristics by responding to unique developmental, chemotactic, and activation cues. Herein, we highlight how recent studies in barrier immunology suggest the presence of skin-homing basophils that harbor a unique identity in terms of phenotype, function, and motility. These concepts may uniquely inform how basophils contribute to diseases at multiple epithelial surfaces and our ability to therapeutically target the innate immune system in disease.

Factors Associated With Refractoriness to an Up to Fourfold Dosage of Antihistamines in Isolated Chronic Spontaneous Urticaria

BACKGROUND

Chronic spontaneous urticaria (CSU) is a common skin disease and has a significant impact on patients' quality of life. The aim of treatment is complete symptom control.

AIM

To identify potential factors associated with antihistamine-refractory isolated CSU and to determine the factors that predict response to second-generation H₁ antihistamines at dosages from one- to fourfold.

METHODS

We conducted a retrospective cohort study, which included adult patients diagnosed with isolated CSU and had complete symptom control. Clinical and laboratory findings were compared between the patients who were responsive to second-generation H₁ antihistamines (< fourfold) and those who were refractory to a fourfold dose. Clinical and laboratory data were compared by dosage in the antihistamine-responsive group.

RESULTS

There were 182 isolated CSU patients who met the study criteria, of whom 150 (82.4%) were responsive to treatment with up to a fourfold dose of second-generation H₁ antihistamines, while 32 (17.6%) were refractory. In univariate analysis, age at onset, body mass index, baseline Urticaria Activity Score-7 (UAS7), white blood cell count, total neutrophil count, neutrophil-lymphocyte ratio, platelet count, and new generation antihistamines were significantly higher in the antihistamine-refractory group. According to multivariate analysis, baseline UAS7 was the only independent factor associated with antihistamine-refractory isolated CSU (odds ratio 1.14, 95% CI 1.01-1.28, P = .03). In the antihistamine-responsive group, white blood cell count tended to predict response to antihistamine treatment (P < .001, 0.04, 0.34 between onefold and twofold, twofold and threefold, and threefold and fourfold, respectively).

CONCLUSION

Baseline UAS7 was an independent factor associated with antihistamine-refractory isolated CSU.

Pathophysiology, Diagnosis, and Management of Chronic Spontaneous Urticaria: A Literature Review

Chronic spontaneous urticaria (CSU) is characterized by recurring wheals that last 6 weeks or longer without an identifiable cause. The estimated point prevalence of CSU worldwide is 1%. Furthermore, it has a significant impact on quality of life in both adults and pediatric patients and their families. Although it is most often a self-limited disease, some patients have urticaria refractory to first-line treatment: second-generation H1 antihistamines. In these patients, the use of targeted monoclonal antibodies is necessary. While omalizumab is the only Food and Drug Administration-approved monoclonal antibody for CSU, others, including ligelizumab, dupilumab, benralizumab, and several orally administered Bruton's tyrosine kinase inhibitors, are also promising therapeutics for reducing the morbidity of CSU. Novel therapies, among others discussed here, are rapidly being developed with new trials and therapeutics being released nearly monthly. Thus, we performed a scoping literature review of randomized controlled trials studying targeted therapies for CSU. We also discuss the pathophysiology, diagnosis, prognosis, and future research directions in CSU.

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.

A Comparative, Three-Arm, Randomized Clinical Trial to Evaluate the Effectiveness and Tolerability of Bilastine vs Fexofenadine vs Levocetirizine at the Standard Dose and Bilastine vs Fexofenadine at Higher Than the Standard Dose (Up-Dosing) vs Levocetirizine and Hydroxyzine (in Combination) in Patients with Chronic Spontaneous Urticaria

Introduction

Though second-generation antihistamines (SGAH) are first-line drugs in chronic spontaneous urticaria (CSU), 50% of patients do not respond to them. In such patients, guidelines recommend either up-dosing of SGAH or combination of different antihistamines. However, the studies comparing these treatment regimens are limited.

Methods

In this comparative, three-arm study, CSU patients were randomized to receive standard dose of either bilastine, fexofenadine, or levocetirizine for 2 weeks. After 2 weeks of treatment, non-responders received double dose of either bilastine or fexofenadine, while hydroxyzine 25 mg once daily was added in the levocetirizine group. Patients were primarily evaluated for improvement in CSU, quality of life, and somnolence.

Results

A total of 110 patients with CSU were recruited. At the end of 4 weeks, 33/39, 26/35, and 22/36 patients in the bilastine, fexofenadine, and levocetirizine groups showed improvement in urticaria symptoms. At week 2, there was no statistical difference in urticaria activity score (UAS7) improvement between any of the groups; however, at week 4, there was a statistical difference between the bilastine and levocetirizine groups (p<0.05). Somnolence was significantly lower in the bilastine group (p<0.05). Bilastine was statistically significant (p<0.05) in the improvement of quality of life as compared to both groups. No major adverse events were reported during study period; however, bilastine was associated with significantly lower levels of AEs compared to levocetirizine (p<0.05).

Conclusion

Two-fold up-dosing of bilastine improves CSU symptoms without compromising safety as compared to two-fold up-dosing of fexofenadine and combination of first- and second-generation antihistamines.

Fexofenadine: review of safety, efficacy and unmet needs in children with allergic rhinitis

Allergic rhinitis (AR) is the most common undiagnosed chronic condition in children. Moderate/severe AR symptoms significantly impair quality of life, and cause sleep disruption, absenteeism and decreased productivity. Additionally, untreated AR predisposes children to asthma and other chronic conditions. Although intranasal corticosteroids are the most effective pharmacologic treatment for AR, oral antihistamines are often preferred. First-generation antihistamines may be chosen to relieve AR symptoms as they are inexpensive and widely available; however, they cause sedative and cardiovascular negative effects due to poor receptor selectivity. Therefore, second-generation antihistamines were developed to reduce adverse effects while retaining efficacy. There are fewer clinical trials in children than adults, therefore, efficacy and safety data is limited, particularly in children under 6 years, highlighting the need to generate these data in young children with AR. Fexofenadine, a highly selective second-generation antihistamine, effectively alleviates symptoms of AR, is non-sedating due to decreased blood-brain barrier permeability, and is devoid of cardiovascular side effects. Importantly, fexofenadine relieves the ocular symptoms of allergic conjunctivitis, which occur concomitantly with AR, improving quality of life. Overall, fexofenadine displays a favorable safety profile and results in greater treatment satisfaction in children compared with other second-generation antihistamines. This review aimed to evaluate and compare the safety and efficacy of fexofenadine with other available first- and second-generation antihistamines in children with AR.

Heparin-binding motif mutations of human diamine oxidase allow the development of a first-in-class histamine-degrading biopharmaceutical

Background

Excessive plasma histamine concentrations cause symptoms in mast cell activation syndrome, mastocytosis, or anaphylaxis. Anti-histamines are often insufficiently efficacious. Human diamine oxidase (hDAO) can rapidly degrade histamine and therefore represents a promising new treatment strategy for conditions with pathological histamine concentrations.

Methods

Positively charged amino acids of the heparin-binding motif of hDAO were replaced with polar serine or threonine residues. Binding to heparin and heparan sulfate, cellular internalization and clearance in rodents were examined.

Results

Recombinant hDAO is rapidly cleared from the circulation in rats and mice. After mutation of the heparin-binding motif, binding to heparin and heparan sulfate was strongly reduced. The double mutant rhDAO-R568S/R571T showed minimal cellular uptake. The short α-distribution half-life of the wildtype protein was eliminated, and the clearance was significantly reduced in rodents.

Conclusions

The successful decrease in plasma clearance of rhDAO by mutations of the heparin-binding motif with unchanged histamine-degrading activity represents the first step towards the development of rhDAO as a first-in-class biopharmaceutical to effectively treat diseases characterized by excessive histamine concentrations in plasma and tissues.

Funding

Austrian Science Fund (FWF) Hertha Firnberg program grant T1135 (EG); Sigrid Juselius Foundation, Medicinska Understödsförening Liv och Hälsa rft (TAS and SeV).

Trends in office visits and treatment for urticaria in children in the United States, 1998-2016

BACKGROUND/OBJECTIVES

Urticaria is a common condition with an estimated prevalence of up to 23% in the pediatric population. Studies characterizing visits and treatments for urticaria in the pediatric population are unavailable. Understanding visit and treatment trends for urticaria in the pediatric population may help inform care for patients with urticaria.

METHODS

A total of 108 278 outpatient records from the National Ambulatory Medical Care Survey representing 3.4 billion visits by patients of age 18 and younger were analyzed. This study included the calendar years 1998 through 2016.

RESULTS

Pediatricians saw the largest proportion of all visits (52.7%). Male and female patients accounted for approximately equal proportions of all visits for urticaria. There was a slight male predominance in visits to pediatricians (53.7%), whereas dermatologists saw female patients more frequently (63.3%). Most visits for urticaria were by non-Hispanic (78.1%) and White (78.2%) patients. H1 antihistamines were the most commonly prescribed treatment (70.3%), whereas topical corticosteroids were prescribed least frequently (4.9%). Topical corticosteroids were most frequently prescribed by dermatologists (7.7%). Non-H1 antihistamine and non-corticosteroid therapy were prescribed in 9.7% of all visits and in 4.5% of visits to pediatricians. Most visits for urticaria were to physicians in metropolitan areas (88.8%). Pediatricians saw the highest number of non-metropolitan area visits (56.3%).

CONCLUSIONS

H1 antihistamines were the most commonly used therapy (70%), consistent with established treatment guidelines. Male and female pediatric patients present equally often for urticaria, but sex differences were seen with visit frequencies to certain specialties.

What's New in the Treatment of Urticaria and Angioedema

Chronic urticaria and angioedema are diseases often managed by Allergy and Immunology specialists. Recent international guidelines have outlined a stepwise approach to management of patients using dose escalation of second-generation antihistamines followed by use of omalizumab and finally cyclosporine in more refractory cases. In select patients (those with refractory chronic urticaria), nonbiologic alternative medications with anti-inflammatory or immunosuppressant activity may be considered. Angioedema without wheals may have several different pathophysiologic mechanisms. Optimal management of mast cell-mediated angioedema is less clear but is often managed similar to chronic spontaneous urticaria. Drug-induced angioedema due to angiotensin-converting enzyme inhibitors is a common cause of angioedema in the emergency department. Although bradykinin is thought to be a primary mediator for this type of angioedema, studies of targeted therapies have been generally disappointing. In contrast, several targeted therapies have been proven successful using acute and preventive approaches for management of hereditary angioedema. Further developments, including novel biologics, novel oral therapies, and gene therapy approaches, may hopefully continue to broaden therapeutic options to ensure optimal individual management of patients with hereditary angioedema.

The efficacy of omalizumab treatment in chronic spontaneous urticaria is associated with basophil phenotypes

BACKGROUND

The mechanisms underlying disease pathogenesis in chronic spontaneous urticaria (CSU) and improvement with omalizumab are incompletely understood.

OBJECTIVES

This study sought to examine whether the rate of clinical remission is concordant with baseline basophil features or the rate of change of IgE-dependent functions of basophils and/or plasmacytoid dendritic cells during omalizumab therapy.

METHODS

Adults (n = 18) with refractory CSU were treated with omalizumab 300 mg monthly for 90 days. Subjects recorded daily urticaria activity scores, and clinical assessments with blood sampling occurred at baseline and on days 1, 3, 6, 10, 20, 30, 60, and 90 following omalizumab. At baseline, subjects were categorized by basophil functional phenotypes, determined by in vitro histamine release (HR) responses to anti-IgE antibody, as CSU-responder (CSU-R) or CSU-non-responder (CSU-NR), as well as basopenic (B) or nonbasopenic (NB).

RESULTS

CSU-R/NB subjects demonstrated the most rapid and complete symptom improvement. By day 6, CSU-R/NB and CSU-NR/NB had increased anti-IgE-mediated basophil HR relative to baseline, and these shifts did not correlate with symptom improvement. In contrast, CSU-NR/B basophil HR did not change during therapy. The kinetics of the decrease in surface IgE/FcεRI was similar in all 3 phenotypic groups and independent of the timing of the clinical response. Likewise, plasmacytoid dendritic cells' surface IgE/FcεRI decline and TLR9-induced IFN-α responses did not reflect clinical change.

CONCLUSIONS

Changes in basophil IgE-based HR, surface IgE, or FcεRI bear no relationship to the kinetics in the change in clinical symptoms. Baseline basophil count and basophil functional phenotype, as determined by HR, may be predictive of responsiveness to omalizumab.

Chronic urticaria in children under 15 years of age: Clinical experience beyond the clinical trials

BACKGROUND/OBJECTIVES

The aim of the study was to describe the clinical characteristics, management, and outcome of a series of children with chronic urticaria (CU).

METHODS

We retrospectively studied children aged <15 years diagnosed with CU in a tertiary teaching hospital in Palma de Mallorca, Spain, between January 2014 and March 2019. CU was defined as persistence of symptoms of wheals, with or without angioedema, for >6 weeks.

RESULTS

Twenty-nine patients (17 girls, mean age 8 years) were included. Family history of atopy was found in 31% of the cases. In 41.3% of patients, episodes of CU were associated with angioedema. Physical triggers were found in 34.5% of the cases. Most episodes of CU were successfully managed with the recommended (60.7%) or double the recommended dose (17.2%) of H1-antihistamines. Quadruple the recommended dose of H1 antihistamines was used in six patients, five of whom were finally treated with off-label omalizumab. Treatment with anti-leukotrienes was needed in one patient. Associated thyroiditis was diagnosed in one patient, which was controlled with levothyroxine.

CONCLUSIONS

Pediatric CU showed features similar to CU in adulthood, including a greater predominance in females and frequent association with personal or family history of atopy. Adult guidelines for the treatment of CU are currently extrapolated to the pediatric population. Specific tools for the assessment of disease activity and impairment of quality of life in pediatric CU are needed for use in prospective studies aimed to define treatment strategies for children with CU.

Hematologic parameters as biomarkers for antihistamine and omalizumab resistance in chronic spontaneous urticaria

Background: Biomarkers of resistance to H₁-antihistamines (AH) and omalizumab in chronic spontaneous urticaria (CSU) are still a matter of debate. Objective: To identify clinical and laboratory attributes of the patient that may be predictive of AH and omalizumab resistance in CSU. Methods: We conducted a retrospective observational study by using the electronic patient record data base of patients with CSU and of sex- and age-matched controls. Patients with CSU were divided into three study groups: the CSU group, patients who responded to AHs; the antihistamine-resistant CSU (AH-CSU) group, patients refractory to a fourfold AH dose; and the control group, composed of a random sample of age- and sex-matched subjects, with a case-control ratio of 1:2. The patients in the AH-CSU group treated with omalizumab were compared according to the response or resistance to omalizumab. Results: A total of 106 subjects in the AH-CSU group, 483 in the CSU group, and 1198 in the control group were compared. Both AH-CSU (112.7 ± 43.1 kU/mL) and CSU (129.5 ± 52.4 kU/mL) groups were associated with higher plasma total IgE levels than control group (103.2 ± 49.5 kU/mL; p < 0.001). The AH-CSU group was characterized by a higher plasma high-sensitivity C-reactive protein level (6.4 ± 3.7 mg/L) than the CSU group (4.3 ± 1.4 mg/L; p < 0.001) and the control group (3.1 ± 1.8 mg/L; p < 0.001). The AH-CSU and CSU groups were characterized by a lower mean ± standard deviation basophil counts (0.18 ± 0.16 cells ×10⁹/L and 0.19 ± 0.11 cells ×10⁹/L, respectively) than the control group (0.22 ± 0.09 cells ×10⁹/L; p < 0.001). The mean platelet volume was higher in the AH-CSU group (11.2 ± 0.3 fL) than in the CSU group (11.1 ± 0.4 fL; p = 0.002) and in the control group (10.3 ± 0.4 fL; p < 0.001). There were no significant differences in the mean levels of lymphocytes, monocytes, eosinophils, basophils, and platelets, and the rates of eosinopenia and basopenia between the patients in the AH-CSU group who responded to and those who were resistant to omalizumab. Conclusion: This study provided additional data of interest to examine the pathophysiologic role of low-grade inflammation and basopenia in patients with CSU and resistant to AHs and omalizumab.

Prevalence of chronic urticaria refractory to antihistamines in Andalucia, Spain

Chronic urticaria (CU) has a devastating effect on the quality of life of patients who suffer from it. The objective of this study is to determine the prevalence of severe chronic spontaneous urticaria (CSU) in adults in eight health areas in Andalucía. A retrospective observational study from January 2019 to December 2019 was conducted with the participation of seven reference hospitals that were analyzed, including a total reference population of 3 159 001 individuals ≥18 years. The analysis was carried out on the characteristics of the population and the estimated prevalence. In total, 369 patients with a diagnosis of CSU refractory to antagonist of histamine were registered. We have found a prevalence of refractory patients of 0.0012% (95% CI 0.0010%-0.0013), ranging from 0.006% to 0.02%. The present study has helped to describe the prevalence and characteristics of patients with severe urticarial. The prevalence is lower than previously reported. We have observed differences between hospital areas. There will be a new line of research at the national level to help improve the identification of patients with CSU.

Clinical characteristics and management of chronic spontaneous urticaria in patients refractory to H1-Antihistamines in Asia, Middle-East and Africa: Results from the AWARE-AMAC study

Background

Chronic urticaria (CU) is a condition characterized by recurrent itchy hives and/or angioedema for ≥6 weeks. Most of the data about CU come from western countries with very little information available about CU in Asia, Africa, and the Middle East.

Methods

AWARE-AMAC is a 24-month prospective, observational, real-world, non-interventional study in patients aged ≥18 years from Asia, the Middle East, and Africa (AMAC) with CU refractory to H1-antihistamines (H1-AH). The main objective was to describe the real-world experience with CU, including clinical characteristics, presence of angioedema, treatment patterns (shifts between treatment classes and changes within a treatment class), investigator-assessed disease control, and the impact on quality of life. Subgroups of interest were type of CU at Baseline and treatment class (based on 2013 urticaria guidelines). There were no mandatory visits and diagnostic/monitoring procedures additional to routine practice, except the patient diary (7-day Urticaria Activity Score) and patient reported outcome assessments.

Results

The focus of the current manuscript is on patients with chronic spontaneous urticaria (CSU), who formed 98% of the sample. Patients were predominantly female (69.6% female, mean age ± SD 39.8 ± 13.29 years). Time since current diagnosis (Mean ± SD) was 28.6 ± 49.06 months. Amongst patients with CSU, 31.0% had comorbid chronic inducible urticaria (CINDU) and 46.4% had a history of angioedema. 91.9% received H1-AH therapy (±other treatments). The most frequently prescribed treatment classes at Baseline were any/combination of medications, not classified under the other 7 treatment classes, named “Others” (30.5%) followed by, omalizumab (OMA; 23.6%) and second-generation H1-AH monotherapy (sgAH; 15.1%). At Month 12, the most prescribed treatment classes (>15%) for patients were OMA (23.5%) and "Other" (21.3%); 19.7% received "No drug". At Month 24, OMA (22.5%), and "Other" (17.9%) were most frequently prescribed; 28.6% received "No drug". Overall, 79.5% of patients had some type of change in treatment. Over the study period, improvement in self-reported QoL increased, which was mirrored by better disease control.

Conclusion

In AMAC countries, the non-recommended "Other" treatment class played a major role in the initial management of CU patients. High usage of H1-AH (±other treatments) and OMA was observed. Treatment changes were observed in a majority of patients. Treatment escalation from sgAH was mostly via OMA. Improvement of disease control and QoL was achieved during the study period.

Trial registration

Observational study (NA).

Urticaria and Angioedema Across the Ages

Chronic urticaria (CU) and angioedema can occur at any age. Although most CU with or without angioedema occurs in adults, it can also present in children or the elderly and can complicate pregnancy and breast-feeding. The presentations of CU and angioedema are different in children, middle-aged adults, and older patients as are the differential diagnoses. Therefore, the management of CU and angioedema in these different age groups and special populations needs to take into account the age-specific features of urticaria and angioedema. Here, we describe the evaluation, diagnosis, and treatment of CU and angioedema in children, middle-aged adults, and older patients. This review focuses on CU with or without angioedema and does not discuss acute urticaria or bradykinin-mediated angioedema.

Cetirizine use in childhood: an update of a friendly 30-year drug

Cetirizine is a second-generation antihistamine, derived from the metabolism of hydroxyzine, highly specific for the H1 receptors, and with marked antiallergic properties. Although its history began more than 30 years ago, it remains one of the most used drugs in children with a leading role in the medical care of children with allergic diseases. Cetirizine use is licensed for paediatric patients for the treatment of allergic rhinitis, and chronic spontaneous urticaria, in Europe in children older than 2 years old and in the USA in children older than 6 months old. This review provides a practical update on the use of cetirizine in children and adolescents.

Current and emerging treatments for chronic spontaneous urticaria

OBJECTIVE

To review the published literature on current and new treatments for chronic spontaneous urticaria (CSU) and to provide guidance on the potential use of these therapeutics.

DATA SOURCES

A PubMed search was performed to include English-language articles with the keywords chronic spontaneous urticaria, pathophysiology, quality of life, and treatments, with a preference to those articles written in the last 5 years. ClinicalTrials.gov was reviewed for recent relevant clinical trials related to potential CSU therapeutics.

STUDY SELECTIONS

Literature was included if it provided information related to the current understanding of the pathophysiology and management of CSU as well as potential novel therapeutics currently in development.

RESULTS

CSU has a significant effect on patients' quality of life. Current therapies include antihistamines, leukotriene receptor antagonists, omalizumab, and immunosuppressants; however, additional treatments are needed. New therapeutics under investigation include IgG1 anti-IgE monoclonal antibodies (ligelizumab), chemoattractant rector-homologous molecule expressed on T_H2 cells antagonists (AZD1981), Bruton tyrosine kinase inhibitors (fenebrutinib), anti-siglec-8 monoclonal antibody (AK002), and topical spleen tyrosine kinase inhibitors (GSK2646264). We review the mechanisms of action as well as recently published data from clinical trials regarding the efficacy and safety of these treatments.

CONCLUSION

The development of new treatments for CSU will lead to improved options for patients and may assist with improving our understanding of disease pathophysiology.

High occurrence of antihistamine resistance in patients with recurrent idiopathic angioedema

Antihistamines are the most prescribed therapy in recurrent idiopathic angioedema, yet little is known about their efficacy. Herein, we report on clinical improvement with antihistamine therapy in 120 patients evaluating angioedema attack frequency. A high incidence (36%) of antihistamine refractory cases was observed. Forty percent of patients on antihistamine prophylaxis suffered from 1 or more angioedema attacks per month. Our findings stress the need for additional treatment options for recurrent idiopathic angioedema.

Treatment of chronic spontaneous urticaria with an inadequate response to H1-antihistamine

The second-generation H1-antihistamines (sgAH) are the first-line symptomatic treatment of patients with chronic spontaneous urticaria (CSU). Up to 50% of the patients will not respond to licensed doses of sgAH. According to the guidelines, the dose of sgAH may be increased up to 4 times the conventional dose. However, even at higher doses, there is a subgroup of patients refractory to the antihistamine treatment. The purpose of this article was to review the different treatment options of antihistamine-refractory CSU patients. This revision examines the available literature for therapies used in chronic urticaria, including omalizumab, ciclosporin A, oral glucocorticoids, leukotriene receptor antagonists, H2 antihistamines, doxepin, dapsone, hydroxychloroquine, phototherapy, methotrexate, mycophenolate mofetil, azathioprine, autohemotherapy, intravenous immunoglobulins and rituximab, between others. After the exhaustive review of the medical literature only few high-quality studies have been identified, mostly for omalizumab. Omalizumab is an anti-immunoglobulin E monoclonal antibody, approved for the treatment of CSU, that has radically changed the management of the patients without good response to sgAH, allowing to reach complete responses in a high percentage of patients. Although actually the therapeutic management of CSU is more effective and safer than before 2014, there is place even for new and more effective treatments. A good number of partial responders and slow responders to omalizumab and a little percentage still of non-responders to available therapies stimulate the development of new drugs that will also be discussed.

High-dose antihistamines for chronic spontaneous urticaria in adults

Chronic spontaneous urticaria (CSU) is a common skin disease characterised by intermittent weals (hives), angioedema or both lasting for at least 6 weeks.1-3 Second-generation antihistamines are widely used to manage symptoms but are not completely effective in many patients at licensed doses.4 Some guidelines recommend off-label use of high-dose antihistamines as the next therapeutic step.2,3 Here, we review the evidence supporting this recommendation.