Neuro-Immuno-Psychological Aspects of Chronic Urticaria

Quality of life, sleep, and psychological well-being in chronic spontaneous urticaria patients receiving omalizumab: a case-control study

Chronic spontaneous urticaria (CSU) impacts both physical and mental well-being, causing distress and sleep disturbances. While omalizumab reduces disease activity, its effects on mental health and quality of life remain unclear. This study assesses the psychosocial burden and sleep disturbances in CSU patients receiving omalizumab compared to healthy controls and explores their relationship with disease parameters. This case--control study included 210 CSU patients receiving omalizumab for at least three months and 210 age- and sex-matched healthy controls. Disease severity was assessed using the Urticaria Activity Score over 7 Days (UAS7) and Urticaria Control Test (UCT), while quality of life was evaluated with the Chronic Urticaria Quality of Life Questionnaire (CU-Q₂oL). Psychological distress and sleep disturbances were measured using validated scales, including the Perceived Stress Scale (PSS), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS). CSU patients had significantly higher scores for perceived stress, depression, anxiety, and daytime sleepiness compared to controls (p < 0.001). Patients with a good response to omalizumab also showed significantly higher psychological distress and poorer sleep quality than controls (p < 0.001). Omalizumab response was good in 29.5%, moderate in 38.6%, and limited in 31.9% of patients. Despite treatment, 32.9% reported no change in quality of life, while 35.7% had mild and 31.4% had moderate improvement. A history of atopic disease was present in 55.7% of patients, who had significantly higher daytime sleepiness scores than those without (p = 0.045). In CSU patients, while omalizumab improves symptoms and quality of life, psychological distress persists in substantial subsets, highlighting the need to address mental health and lifestyle factors.

Serum MRGPRX2 and substance P levels are biomarkers of disease activity rather than an antihistamine response in chronic spontaneous urticaria

In chronic spontaneous urticaria (CSU), the role of Mas-related G protein-coupled receptor X2 (MRGPRX2) and substance P (SP) as biomarkers of disease severity and the antihistamine response remains unclear. The study aims to examine the correlations between serum MRGPRX2 and SP levels, disease severity, and antihistamine response in patients with CSU. This study included 120 CSU patients and 30 healthy controls. Based on the Urticaria Activity Score over 7 days (UAS7), the patients with CSU were divided into two categories: severe (UAS7 ≥ 28) and non-severe (UAS7 < 28). Severe CSU patients received 20 mg of bilastine, titrated up to 80 mg based on Urticaria Control Test (UCT) results at days 15, 30, and 60. Serum MRGPRX2 and SP levels were measured at baseline for all participants and after two months in severe CSU patients. The Kruskal-Wallis test and Dunn's corrections were used to examine differences in multiple comparisons. Spearman's correlation assessed the relationships between MRGPRX2 and SP levels, age, and urticaria duration. Receiver Operating Characteristic (ROC) curves were created to identify the optimal serum levels of MRGPRX2 and SP for distinguishing severe CSU. Additionally, univariate and multivariate logistic regression analyses were conducted to identify risk factors associated with severe CSU. Serum levels of MRGPRX2 and SP were significantly higher in patients with severe CSU compared to non-severe patients (P < 0.001 and P = 0.01) but were comparable to controls (P > 0.05). These levels were positively correlated with the UAS7 (P < 0.001 and P = 0.01), with no correlation between MRGPRX2 and SP levels (P = 0.28). MRGPRX2 ≥ 11.67 ng/mL and SP ≥ 97.66 pg/mL were identified as independent risk factors for severe CSU (OR 48.21 95%CI 13.00-178.82; P < 0.001 and OR 3.19 95% CI 1.10-9.24, P = 0.03). Among the severe CSU patients, the baseline MRGPRX2 and SP levels did not significantly differ across the antihistamine response groups (P > 0.05); serum MRGRPX2 levels remained consistent over time after antihistamine treatment (P = 0.41), whereas serum SP concentrations significantly decreased (P < 0.001). Serum MRGPRX2 and SP levels are associated with disease severity in CSU patients but do not predict antihistamine response in severe cases.

Urticaria in China: incidence, prevalence, and disability-adjusted life years compared with G20 countries: findings from the Global Burden of Disease study 2021

Urticaria has become a major public health challenge in China, yet comprehensive national data assessments are lacking. This study analyzes the burden of urticaria in China compared to G20 countries from 1990 to 2021. Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021, we examined the incidence, prevalence, and disability-adjusted life years (DALYs) of urticaria by age and sex in China. Temporal trends were assessed using Average Annual Percent Change (AAPC) estimates. We also decomposed the changes in new cases, patient numbers, and urticaria burden in G20 countries and globally from 1990 to 2021. In 2021, China reported 17.30 million (95% uncertainty interval, 15.37-19.25) new cases of urticaria, 9.87 million (8.72-10.99) existing cases of urticaria, and 0.59 million (0.39-0.82) DALYs due to urticaria, ranking second among G20 countries. These metrics peaked in females under 5 years old. Age-standardized rates in China were lower than the global average and remained stable from 1990 to 2021. The under-5 age group showed the fastest growth in prevalence and DALY rates. The number of urticaria patients increased by 8.52%, with population growth contributing 19.86%, aging - 11.31%, and age-specific prevalence - 0.03%. Despite stable age-standardized rates, the absolute burden of urticaria in China has risen, particularly among females under 5 years old, highlighting the need for targeted public health interventions. Improving public emergency awareness and response is critical for urticaria patients, who may develop severe systemic diseases and fatal allergic symptoms.

Beyond the itch: the complex interplay of immune, neurological, and psychological factors in chronic urticaria

Chronic urticaria (CU) arises from a multifaceted interplay of immunological, neurological, and psychological components. Immune dysregulation, mediated through both immunoglobulin E (IgE)-dependent and IgE-independent pathways, plays a pivotal role in CU pathogenesis, involving key effector cells such as mast cells (MCs), basophils, and eosinophils. This dysregulation culminates in the release of histamine, prostaglandins, and other mediators, which precipitate pruritus. The chronicity of the disease leads to sustained pruritic symptoms, contributing to both central and peripheral sensitization. The excitation of the itch circuit is augmented, leading to the release of neurotransmitters and neuropeptides, which subsequently interact with immune cells. Psychological factors such as depression, anxiety, and stress exacerbate CU symptoms and diminish quality of life. These factors disrupt the hypothalamic-pituitary-adrenal (HPA) axis and the autonomic nervous system (ANS). Furthermore, the act of scratching activates the reward circuit, resulting in the manifestation of the itch-scratching cycle. Current treatments, such as antihistamines, omalizumab, and cyclosporine, demonstrate variable efficacy and are often associated with adverse effects. A holistic approach addressing both psychological and physiological aspects is advocated. This review highlights the critical importance of understanding neuroimmune interactions and the influence of psychosomatic factors in CU. It aims to enhance diagnostic and therapeutic strategies by integrating psychological, neurological, and immunological perspectives.

Unraveling the causative connection between urticaria, inflammatory cytokines, and mental disorders: Perspectives from genetic evidence

BACKGROUND

The genetic association between urticaria and mental disorders and whether inflammatory cytokines mediate this process remains unclear.

MATERIALS AND METHODS

A Mendelian randomization (MR) approaches to elucidate the causal relationship between urticaria and mental disorders and to validate the mediation of inflammatory cytokines. Genome-wide association study (GWAS) databases used were obtained from Psychiatric Genomics Cooperation (PGC), GWAS Catalog, and FinnGen Consortium. Our study was conducted using inverse variance weighted (IVW) and Bayesian weighted MR (BWMR) methods for joint analysis.

RESULTS

The MR results showed that urticaria increased the risk of attention deficit hyperactivity disorder (ADHD) (odds ratio [OR] = $ = $ 1.088, 95% confidence interval [CI]: 1.026-1.154, p = $ = $ 0.0051); cholinergic urticaria increased the risk of bipolar disorder (BD) (OR = $ = $ 1.012, 95% CI: 1.001-1.022, p = $ = $ 0.0274); dermatographic urticaria increased the risk of ADHD (OR = $ = $ 1.057, 95% CI: 1.005-1.112, p = $ = $ 0.0323); idiopathic urticaria increased the risk of schizophrenia (SCZ) (OR = $ = $ 1.057, 95% CI: 1.005-1.112, p = $ = $ 0.0323); other unspecified urticaria increased the risk of ADHD (OR = $ = $ 1.085, 95% CI: 1.023-1.151, p = $ = $ 0.0063). We found that eight inflammatory cytokines were negatively associated with mental disorders and seven inflammatory cytokines were positively associated with mental disorders. Finally, our results suggested that inflammatory cytokines do not act as mediators between urticaria and mental disorders.

CONCLUSIONS

Our study reveals a causal relationship between urticaria and the increased risk of mental disorders. We suggest that the treatment of urticaria could incorporate psychiatric interventions and mental health assessment of patients.

Shedding light on dermographism: a narrative review

Dermographism is a common subtype of chronic urticaria. It generally manifests as a linear wheal after scratching or friction, with or without angioedema. The pathophysiology is not clear, but currently, we believe that the stimulation of the skin by mechanical stress leads to the activation of mast cells, which provoke the release of histamine and pro-inflammatory mediators, ultimately forming wheal along the stressed area. The gold standard for diagnosis is a medical history and provocation test or dermatographic test. As one of the subtypes of chronic urticaria, the Urticaria Control Test (UCT), Chronic Urticaria Quality of Life questionnaire (CU-Q2oL), and Dermatology Life Quality Index (DLQI) are also effective tools for evaluating disease control in dermographism patients. In addition to avoiding triggers, nonsedating H1 antihistamines are the first-line medications recommended by EAACI and other guidelines; for those who do not respond to standard doses, the recommended dosage can be increased up to 4 times. When necessary, the off-label use of omalizumab can be considered, and some drugs with potential therapeutic effects are still being explored. However, there is still a lack of biomarkers for predicting disease severity, efficacy, and prognosis. Here, we review what we know about dermographism and some points that need exploration in the future.

Efficacy and Mechanism of Acupoint Catgut Embedding in the Treatment of Chronic Spontaneous Urticaria: Protocol for a Randomized Double-Blind Placebo-Controlled Trial

BACKGROUND

Chronic spontaneous urticaria (CSU) is a common chronic inflammatory skin disease that manifests as itching and wheals, seriously affecting quality of life. Clinical observations and previous research trials have shown that acupuncture is safe and effective for the treatment of CSU. However, there are problems, such as a short duration of action and frequent treatment. Compared with traditional acupuncture, acupoint catgut embedding (ACE) has the advantages of a longer effect and higher compliance. Clinical trials are needed to prove its efficacy and mechanism of action.

OBJECTIVE

This trial aims to provide definitive evidence for the treatment of CSU with ACE and explore the mechanism of ACE.

METHODS

This is a randomized, double-blind, placebo-controlled trial. In this trial, 108 participants aged 18-60 years with a diagnosis of CSU and no history of ACE will be randomly assigned to 2 groups (1:1 ratio) using the Statistical Analysis System: treatment (ACE) and control (sham ACE). The participants and efficacy evaluators will be blinded to the grouping. Both the ACE and sham ACE groups will undergo acupuncture, but the sham ACE group will not receive catgut sutures. Treatment will be performed twice weekly for 8 weeks, with a 1-week run-in period and a 16-week follow-up period. Twenty patients will be randomly selected to undergo functional magnetic resonance imaging before and after the treatment period. The primary outcome will be the urticaria activity score over 7 days (UAS7). We will use R (version 4.0.1; R Project for Statistical Computing) to perform ANOVA and independent samples t tests to compare the differences within and between groups before and after treatment by judging the rejection range based on a significance level of .05.

RESULTS

The study protocol has been approved by the Ethics Committee of Guang'anmen Hospital on September 7, 2022, and has been registered on November 30, 2022. Recruitment began on March 1, 2023. A total of 4-6 participants are expected to be recruited each month. The recruitment is planned to be completed on March 1, 2025, and we expect to publish our results by the winter of 2025. As of November 1, 2023, we have enrolled 25 participants with CSU.

CONCLUSIONS

This randomized, double-blind, placebo-controlled trial aims to provide definitive evidence for the treatment of CSU with ACE and explore the mechanism of ACE. We hypothesize that wheals and itching will show greater improvement in participants receiving active therapy than in those receiving sham treatment. The limitations of this study include its single-center trial design, small sample size, and short treatment duration, which may have certain impacts on the research results.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2200066274; https://www.chictr.org.cn/showprojEN.html?proj=179056.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/54376.

Associations of Gut and Circulating Microbiota with Circulating Vitamin D3, Type I Interferon, and Systemic Inflammation in Chronic Spontaneous Urticaria Patients

Objective

To analyze the associations of the gut and circulating microbiota with circulating vitamin D3 (VD3), type I interferon (IFNI), systemic inflammation, and clinical profiles in chronic spontaneous urticaria (CSU) patients.

Methods

A total of 36 CSU patients with VD3 insufficiency (VDI; serum 25(OH)VD3 <30 ng/mL) and 36 sex-, age-, and body mass index-matched CSU patients with non-VDI were enrolled. Fecal and serum bacteria were identified through 16S rRNA sequencing, and serum 25(OH)VD3 and inflammation biomarkers were assessed using ELISA kits. IFNI response was determined by measuring the stimulatory activity of serum on IFNI-stimulated response element in HEK293 cells in vitro with luciferase assays.

Results

Higher urticarial activity score over 7 days (UAS7), higher frequency of levocetirizine resistance, and more severe proinflammation but weaker IFNI response were observed in VDI than non-VDI patients (all P<0.05). IFNI response was strongly positively associated with serum 25(OH)VD3 level in both groups (P<0.001). Compared to non-VDI patients, abundance of the fecal genera Prevotella 9, Escherichia-Shigella, and Klebsiella was significantly increased, while Bacteroides, Faecalibacterium, and Agathobacter were remarkably reduced in VDI patients (all P<0.05). Burkholderia-Caballeronia-Paraburkholderia (40.95%), Acinetobacter (3.05%), and Aquabacterium (2.37%) were the top three bacteria in sera from VDI patients. Both serum 25(OH)VD3 level and IFNI response were positively associated with fecal Bacteroides in the two groups (P<0.05). In non-VDI patients, there were moderately positive associations between IFNI response and fecal Lachnoclostridium, unclassified_f__Lachnospiraceae, and Phascolarctobacterium and between serum 25(OH)VD3 level and fecal Lachnoclostridium (all P<0.01). Circulating microbiota in VDI patients was closely related only to proinflammation and UAS7 (both P<0.05).

Conclusion

Changes in gut but not circulating microbiota composition are associated with serum 25(OH)VD3 insufficiency and impaired IFNI homeostasis, which points to greater disease severity (UAS7) and systemic proinflammation in CSU patients.

Identification of key genes and molecular mechanisms of chronic urticaria based on bioinformatics

Chronic urticaria (CU) is characterized by persistent skin hives, redness, and itching, enhanced by immune dysregulation and inflammation. Our main objective is identifying key genes and molecular mechanisms of chronic urticaria based on bioinformatics. We used the Gene Expression Omnibus (GEO) database and retrieved two GEO datasets, GSE57178 and GSE72540. The raw data were extracted, pre-processed, and analyzed using the GEO2R tool to identify the differentially expressed genes (DEGs). The samples were divided into two groups: healthy samples and CU samples. We defined cut-off values of log2 fold change ≥1 and p < .05. Analyses were performed in the Kyoto Encyclopaedia of Genes and Genomes (KEGG), the Database for Annotation, Visualization and Integrated Discovery (DAVID), Metascape, Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and CIBERSOFT databases. We obtained 1613 differentially expressed genes. There were 114 overlapping genes in both datasets, out of which 102 genes were up-regulated while 12 were down-regulated. The biological processes included activation of myeloid leukocytes, response to inflammations, and response to organic substances. Moreover, the KEGG pathways of CU were enriched in the Nuclear Factor-Kappa B (NF-kB) signaling pathway, Tumor Necrosis Factor (TNF) signaling pathway, and Janus kinase/signal transducers and activators of transcription (JAK-STAT) signaling pathway. We identified 27 hub genes that were implicated in the pathogenesis of CU, such as interleukin-6 (IL-6), Prostaglandin-endoperoxide synthase 2 (PTGS2), and intercellular adhesion molecule-1 (ICAM1). The complex interplay between immune responses, inflammatory pathways, cytokine networks, and specific genes enhances CU. Understanding these mechanisms paves the way for potential interventions to mitigate symptoms and improve the quality of life of CU patients.

[Recognition and management of relevant comorbidities in chronic spontaneous urticaria]

Various mechanisms contributing to the activity of chronic spontaneous urticaria (CU) have been postulated. Associated comorbidities are increasingly leading to the discovery of further signaling pathways which may support the activity of chronic urticaria or contribute to low-grade systemic inflammation. Moreover psychoimmunological factors may also be involved. The aim of this work is to improve the clinical care of patients with CU by increasing knowledge regarding optional influencing factors due to comorbidities and to possibly influence disease activity. Chronic urticaria due to autoimmune mechanisms may dispose to other autoimmune diseases, especially autoimmune thyroiditis, which can trigger chronic disease. Association of CU with metabolic syndrome has received little attention to date. Obesity may contribute to low-grade systemic inflammation by cytokine-secreting adipose tissue and hence to mediator-release of mast cells. Furthermore, neuroimmunological pathways, especially increased release of substance P, an activating ligand of Mas-related G protein-coupled receptor X2 (MRGPX2) on mast cells, should be addressed when optimizing therapy.

[Mast Cell-Neutrophil Communication Regulates Allergic Diseases]

Allergic diseases (e.g., food allergies) are a growing problem, with increasing numbers of individuals experiencing them worldwide. Congruently, the adverse reactions (e.g., anaphylaxis) associated with the administration of vaccines against emerging infectious diseases such as coronavirus disease 2019 (COVID-19) have become a familiar problem. Allergic diseases, which have a wide variety of symptoms, are difficult to prevent or cure; treatment is currently limited to therapeutic drugs or allergen immunotherapy. Therefore, elucidating new allergic regulatory factors that control the allergic (i.e., mast cell) responses is important. While investigating the regulatory mechanisms of the wide range of allergic responses of mast cells, we found that the affinity of allergens to immunoglobin E (IgE) regulates allergic inflammation through the differences in the secretory responses of mast cells and the types and interactions of the cells infiltrating the tissues. Here, we present our recent findings regarding the affinity of allergens to IgE in regulating allergic inflammation, heterogeneous secretory granules inducing diverse secretory responses, and mast cells interacting with neutrophils, thereby regulating the various allergic responses.

A Patient Charter for Chronic Urticaria

Chronic urticaria (CU) is the recurring development of wheals (aka "hives" or "welts"), angioedema, or both for more than 6 weeks. Wheals and angioedema occur with no definite triggers in chronic spontaneous urticaria, and in response to known and definite physical triggers in chronic inducible urticaria. Approximately 1.4% of individuals globally will have CU during their lifetime. The itching and physical discomfort associated with CU have a profound impact on daily activities, sexual function, work or school performance, and sleep, causing significant impairment in a patient's physical and mental quality of life. CU also places a financial burden on patients and healthcare systems. Patients should feel empowered to self-advocate to receive the best care. The voice of the patient in navigating the journey of CU diagnosis and management may improve patient-provider communication, thereby improving diagnosis and outcomes. A collaboration of patients, providers, advocacy organizations, and pharmaceutical representatives have created a patient charter to define the realistic and achievable principles of care that patients with CU should expect to receive. Principle (1): I deserve an accurate and timely diagnosis of my CU; Principle (2): I deserve access to specialty care for my CU; Principle (3): I deserve access to innovative treatments that reduce the burden of CU on my daily life; Principle (4): I deserve to be free of unnecessary treatment-related side-effects during the management of my CU; and Principle (5): I expect a holistic treatment approach to address all the components of my life impacted by CU. The stated principles may serve as a guide for healthcare providers who care for patients with CU and translate into better patient-physician communication. In addition, we urge policymakers and authors of CU treatment guidelines to consider these principles in their decision-making to ensure the goals of the patient are achievable.

Biomarkers of Autoimmune Chronic Spontaneous Urticaria

PURPOSEOF REVIEW

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

RECENT FINDINGS

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