Pathogenesis of chronic urticaria

Comparative efficacy and safety of the treatment by Omalizumab for chronic idiopathic urticaria in the general population: A systematic review and network meta-analysis

BACKGROUND

Omalizumab is the only licensed drug that serves as a third-line treatment for chronic idiopathic urticaria (CIU). The optimum doses of omalizumab remain controversial. Therefore, this study aims to estimate the efficacy and safety of different doses of omalizumab in the treatment of CIU patients.

MATERIALS AND METHODS

Four databases were searched from the database's creation to April 8, 2023. Several keywords such as omalizumab and urticarias were used to retrieve related studies. The meta-analytical outcomes were analyzed in R 4.2.1 software and Stata 15.1 software. Cochrane risk-of-bias tool Ver. 2 was used to evaluate the risk of bias in randomized controlled trials (RCTs).

RESULTS

In total, 2331 patients were included. Five indexes were employed to assess, including weekly Itch Severity Score (ISS7), weekly Hive Severity Score (HSS7), weekly Urticaria Activity Score (UAS7), Dermatology Life Quality Index (DLQI), and adverse events (AE). A 300 mg dose of omalizumab was the optimum dose to treat CIU, followed by the 150 mg dose. Furthermore, 600 mg of omalizumab only showed a significant difference from the placebo in HSS7. No significant statistical difference was observed in AE. Meta-regression analysis revealed that time, as a covariate, was statistically significant in the comparison of omalizumab 150 mg with placebo.

CONCLUSION

300 mg of omalizumab was the optimum dosage to treat CIU patients, with a 150 mg dose also exhibiting good efficacy. Further studies are required to explore the efficacy and safety of different doses of omalizumab in the treatment of CIU patients.

Mechanisms of histamine release from mast cells beyond the high affinity IgE receptor in severe chronic spontaneous urticaria

There is growing evidence suggesting that in a subset of patients with severe chronic urticaria [CSU] mast cells are activated via mechanisms that bypass the high affinity IgE receptor. This might explain why some patients do not respond at all to anti-IgE therapy [omalizumab]. The present article reviews the pathogenic mechanisms able to lead to histamine release from mast cells described so far in patients with CSU. These include the activation of the coagulation cascade, the activation of the complement system, the activation of the MRGPRX2 receptor, and the platelet activating factor vicious circle. The article suggests some possible interpretations for the clinical events occurring in this specific subset of patients.

Chronic Urticaria Suspected to be Caused by a 13.5 mg Levonorgestrel Intrauterine Device (Skyla®)

Chronic urticaria (CU) is a hive-like rash lasting over six weeks. Common associations include low vitamin D, thyroid autoantibodies, and Helicobacter pylori (H. pylori) infection, among others. Progesterone has been documented to trigger CU, by endogenous or exogenous progesterone. The use of intrauterine devices (IUDs) has been a popular source of birth control, with many containing progesterone. Although rarely reported, some patients have been seen to have an urticarial reaction after implantation of an IUD. Here, we present a case of a patient with progesterone-induced chronic urticaria, likely triggered by implantation of a 13.5 mg intrauterine device implant (Skyla®, Bayer, Whippany, NJ, USA). To the best of our knowledge, this is the first case to report the association between Skyla® and chronic urticaria.

Basophil Characteristics as a Marker of the Pathogenesis of Chronic Spontaneous Urticaria in Relation to the Coagulation and Complement Systems

Chronic spontaneous urticaria (CSU) is a common skin disorder characterized by daily or almost daily recurring skin edema and flare with itch and pruritus anywhere on the body for more than 6 weeks. Although basophil- and mast cell-released inflammatory mediators, such as histamine, play important roles in the pathogenesis of CSU, the detailed underlying mechanism is not clear. Since several auto-antibodies, IgGs which recognize IgE or the high-affinity IgE receptor (FcεRI) and IgEs against other self-antigens, are detected in CSU patients, they are considered to activate both mast cells in the skin and basophils circulating in the blood. In addition, we and other groups demonstrated that the coagulation and complement system also contribute to the development of urticaria. Here, we summarized the behaviors, markers and targets of basophils in relation to the coagulation-complement system, and for the treatment of CSU.

Dermatologic manifestations of thyroid disease: a literature review

Introduction

Thyroid hormone is considered one of the key regulatory hormones for skin homeostasis. Multiple organs are affected by the release of peripheral thyroid hormones (T4 and T3) further regulating various functions at a cellular level. Specifically, skin is considered an important target organ in which the thyroid hormone has a significant impact. Multiple skin diseases are associated with thyroid hormone dysregulation. However, other striking dermatologic manifestations are seen in nails and hair as well. Hypothyroidism, hyperthyroidism, and thyroid cancer can have an array of cutaneous manifestations, and we present the recent updates in this field.

Methods

A PubMed search was performed for updates in any new skin disease findings and treatments between 2010 and 2022. Research published in the past decade and previously known foundational skin findings associated with thyroid disease were presented in this review.

Conclusion

Cutaneous manifestations of thyroid disease is one of the first notable signs of thyroid hormone dysregulation. This article reviews the recent updates on the thyroid and skin interplay, and it further discusses overt visible findings and various available treatment modalities.

Atypical Presentation of Sjogren’s Syndrome With Chronic Urticaria: A Case Report and Literature Review

We present a case of a 26-year-old female with a history of 6-8 months of recurrent severe allergic reactions with anaphylaxis who presented with bilateral shoulder arthralgia and inflammatory arthritis of the right hand involving metacarpophalangeal joints (MCP). Physical examination was significant for tenderness in shoulder and knee joints, swelling, warmth, and tenderness involving MCP joints of the right hand. Schirmer's test was positive in both eyes. Further workup revealed positive antinuclear antibody (ANA) (speckled pattern), anti-Ro antibodies, and elevated inflammatory markers including erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). The patient was diagnosed with Sjogren's syndrome and was started on methotrexate once weekly and hydroxychloroquine with significant improvement in the symptoms. Also, we review the literature describing the association between chronic urticaria and rheumatological diseases. This case highlights the varied presentation of rheumatological diseases.

Type 1 Diabetes Mellitus and Autoimmune Diseases: A Critical Review of the Association and the Application of Personalized Medicine

Type 1 Diabetes Mellitus (T1DM) is a common hyperglycemic disease characterized by the autoimmune destruction of insulin-producing beta cells of the pancreas. Various attempts have been made to understand the complex interplay of genetic and environmental factors which lead to the development of the autoimmune response in an individual. T1DM is frequently associated with other autoimmune illnesses, the most common being autoimmune thyroid disorders affecting more than 90% of people with T1D and autoimmune disorders. Antithyroid antibodies are present in around 20% of children with T1D at the start of the illness and are more frequent in girls. Patients with T1DM often have various other co-existing multi-system autoimmune disorders including but not limited to thyroid diseases, parathyroid diseases, celiac disease, vitiligo, gastritis, skin diseases, and rheumatic diseases. It is a consistent observation in clinics that T1DM patients have other autoimmune disorders which in turn affect their prognosis. Concomitant autoimmune illness might affect diabetes care and manifest itself clinically in a variety of ways. A thorough understanding of the complex pathogenesis of this modern-day epidemic and its association with other autoimmune disorders has been attempted in this review in order to delineate the measures to prevent the development of these conditions and limit the morbidity of the afflicted individuals as well. The measures including antibody screening in susceptible individuals, early identification and management of other autoimmune disorders, and adoption of personalized medicine can significantly enhance the quality of life of these patients. Personalized medicine has recently gained favor in the scientific, medical, and public domains, and is frequently heralded as the future paradigm of healthcare delivery. With the evolution of the ‘omics’, the individualization of therapy is not only closer to reality but also the need of the hour.

Do Antinuclear Antibodies Influence the Clinical Features of Chronic Spontaneous Urticaria?: A Retrospective Cohort Study

Background

Antinuclear antibody (ANA) is often used as a screening test for autoimmune comorbidities in patients with chronic spontaneous urticaria (CSU). However, the relationship of ANA status and the clinical course of the disease have not been fully described.

Objectives

To compare clinical features of CSU patients who are positive and negative for ANA.

Methods

This was a retrospective cohort study that enrolled CSU patients attending the Urticaria Clinic at Siriraj Hospital from 2013 to 2019. Demographics, clinical characteristics, laboratory investigations, and treatments were collected until July 2021. All patients were investigated for ANA. Clinical feature data was compared between CSU patients with positive ANA and negative ANA groups using the 2-sample t-test and the Mann-Whitney U test for quantitative variables. The chi-squared test or Fisher's exact test was conducted to explore the association of qualitative variables. Disease relapse and remission were analysed via Kaplan-Meier survival analysis.

Results

Of 323 CSU patients, 31% had positive ANA. There were no significant differences in disease severity or impairment in quality of life. Patients with a positive ANA test had significantly lower prevalence of allergic rhinitis (p = .048) and significantly higher level of erythrocyte sedimentation rate (p = 0.007). Kaplan-Meier survival analysis showed that 2% of ANA positive CSU patients achieved remission status after one year and 28% did so after five years. There was no statistically significant difference in time to remission and time to relapse between ANA-positive and negative groups.

Conclusion

Positive ANA in CSU patients could not indicate the differences in main disease characteristics from the ANA-negative CSU patients. Investigation for ANA may be useful in CSU patients who are suspected of having autoimmune diseases.

Chemometrics assisted untargeted metabolomic analysis to explore metabolic alterations in chronic urticaria via LC/Q-TOF/MS/MS

Chronic urticaria (CU) is a common disease characterized by the development of recurrent itchy blisters and/or angioedema lasting longer than 6 weeks. The evidence-based diagnosis of CU is described in the most recent urticaria guideline. Metabolomics has the potential to offer diagnostic biomarkers for the detection and prognosis of diseases and predict the efficacy and safety of pharmaceutical interventions. Determining the variation in metabolites found in the plasma of CU patients (n = 20) and 20 controls has therefore been the goal of this investigation. Samples were analyzed using liquid chromatography quadrupole time-of-flight mass spectrometry after applying acetonitrile precipitation. For the purpose of identifying and characterizing metabolites, the METLIN database was utilized. According to results, 21 metabolites were found to be significantly (VIP score > 0.7, p < .05 and fold analysis >1.5) altered. Differentiations between each group were successful via both OPLS-DA and ROC analysis. While plasma allantoate, homogentisate, indole acetate, proline, phenylalanine levels decreased in CU patients compared to healthy subjects, tryptophan, spermidine, phenyl pyruvate, oleic acid, lysine, valine, ornithine, histidine, glutamate, leucine, kynurenine, hypoxanthine, tyrosine, glucose, creatine and cortisol levels were significantly increased. Diagnosis of CU could be achieved by evaluating the metabolic profile of patients.

Annular urticarial lesions

Annular urticarial configurations are often associated with acute and chronic urticaria. Such lesions may be short-lived, migratory, transient, pruritic, and resolving with no residual evidence, making the diagnosis of urticaria an obvious one. Annular urticarial lesions can be the presenting signs of various cutaneous and systemic diseases. The differentiation of urticarial lesions may be made by considering the duration of an individual lesion longer than 24 hours, with burning and pain sensation in the lesions or lack of pruritus; skin marks such as postinflammatory pigmentation or purpura after resolution of the lesions; associated scaling or vehiculation in the lesions; systemic symptoms such as arthralgia, fever or fatigue; and several abnormal laboratory findings. The main differential diagnoses of annular urticarial lesions include urticarial vasculitis, autoinflammatory syndromes, hypersensitivity reactions, and connective tissue diseases.

Serum Levels of Vascular Endothelial Growth Factor, Platelet Activating Factor and Eosinophil-Derived Neurotoxin in Chronic Spontaneous Urticaria—A Pilot Study in Adult Patients

Chronic spontaneous urticaria (CSU) is a skin disease characterized by the presence of wheals, angioedema, or both for at least 6 weeks. Although, CSU is often regarded as autoimmune in nature, its etiology is not fully explained and interactions between various small molecules are still taken under account. The aim of this research was to investigate the mean serum concentration of vascular endothelial growth factor (VEGF), platelet activating factor (PAF), and eosinophil-derived neurotoxin (EDN) in relation to the disease activity and pruritus intensity in adult patients with CSU. Fifteen patients with CSU and 15 healthy subjects participated in this pilot study. Blood samples were taken to examine the mean serum levels of VEGF, PAF, and EDN by the enzyme-linked immunosorbent assay test (ELISA). The Urticaria Activity Score (UAS7) and The Visual Analogue Scale (VAS) were used to assess the disease activity and the pruritus intensity, respectively. Obtained results revealed that VEGF, PAF, and EDN concentrations were higher in patients with CSU compared with those of the control group, but only for VEGF it was statistically significant (p = 0.008). However, levels of all investigated cytokines were not significantly correlated neither with the disease activity nor with the pruritus intensity. Our results showed higher serum levels of VEGF, PAF, and EDN among CSU patients which may highlight a functional role of these cytokines in the disease’s pathogenesis. In contrast, VEGF, PAF, or EDN might not be useful to reflect the severity of symptoms.

Epidemiology of urticaria in China: a population-based study

Background:

Urticaria is a common skin disease characterized by episodes of wheals, and it has a negative effect on patients’ quality of life. Large-scale population-based epidemiological studies of urticaria are scarce in China. The aim of this survey was to determine the prevalence, clinical forms, and risk factors of urticaria in the Chinese population.

Methods:

This survey was conducted in 35 cities from 31 provinces, autonomous regions, and municipalities of China. Two to three communities in each city were selected in this investigation. Participants completed questionnaires and received dermatological examinations. We analyzed the prevalence, clinical forms, and risk factors of urticaria.

Results:

In total, 44,875 questionnaires were distributed and 41,041 valid questionnaires were collected (17,563 male and 23,478 female participants). The lifetime prevalence of urticaria was 7.30%, with 8.26% in female and 6.34% in male individuals (P < 0.05). The point prevalence of urticaria was 0.75%, with 0.79% in female and 0.71% in male individuals (P < 0.05). Concomitant angioedema was found in 6.16% of patients. Adults had a higher prevalence of urticaria than adolescents and children. Living in urban areas, exposure to pollutants, an anxious or depressed psychological status, a personal and family history of allergy, thyroid diseases, and Helicobacter pylori infection were associated with a higher prevalence of urticaria. Smoking was correlated with a reduced risk of urticaria.

Conclusion:

This study demonstrated that the lifetime prevalence of urticaria was 7.30% and the point prevalence was 0.75% in the Chinese population; women had a higher prevalence of urticaria than men. Various factors were correlated with urticaria.

Platelet Count and IgE Level in Chronic Idiopathic Urticaria: A Case-control Study

BACKGROUND AND AIM

Chronic Urticaria is an allergic disorder that affects about 0.5 to 5% of the population in different communities. The disease's chronic course and long-term onset impose high economic and psychological costs on communities, adversely affecting individual and social life. Platelets play a role in various pathophysiological processes, including inflammation and immunology. Growing evidence suggests that platelets are actively involved in the pathogenesis of various inflammatory disorders, including inflammatory skin diseases. This study investigated the relationship between platelet and immunoglobulin-E markers and chronic idiopathic urticaria.

MATERIALS AND METHODS

In the present case-control study, for the study population, patients with chronic idiopathic urticaria were referred to the Asthma and Allergy Clinic, and their caregivers were selected as the case and control groups, respectively. In this study, the mean platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), and Total IgE values were simultaneously measured in the case and control groups. After taking 5CCs of venous blood, a blood sample was sent to the laboratory for platelet and IgE marker measurements.

RESULTS

100 patients and 100 healthy persons were evaluated in this study. The mean age in the case group was 34.95, and in the control group was 35.78 years. The results showed that the mean values of PLT, MPV, PDW, and Total IgE in the case group were 12.86, 9.83, 252190, and 147.05, respectively. The mean values of PLT, MPV, PDW, and Total IgE in the control group were 16.93, 7.53, 231410, and 15.29, respectively, which was statistically significant (P = 0.001). Moreover, total IgE in the Autologous Serum Skin Test (ASST) positive group was higher than ASST negative group and was statistically significant (P = 0.001).

CONCLUSION

The study results indicate the possible role of platelets in urticaria and inflammation. MPV in patients with chronic urticaria was higher than in the control group. The present study showed no significant relationship between the severity of urticaria and platelet markers, but there was a significant relationship between the severity of urticaria and ASST. Moreover, the severity of urticaria was higher in the positive skin test group.

Pharmacokinetics of diphenhydramine following single-dose intravenous and oral administration in non-fasted adult horses

Diphenhydramine is an H1 receptor antagonist used to control urticaria and other allergic signs caused by type I hypersensitivity reactions in horses (Equus caballus). Limited studies have been conducted on pharmacokinetics of this drug in horses, with no studies involving oral formulations. Our study investigated pharmacokinetics of an oral diphenhydramine formulation compared to intravenous administration in non-fasted adult horses. Six healthy horses underwent a single administration of three different doses of diphenhydramine (1 mg/kg intravenously, 1 mg/kg intragastrically, and 5 mg/kg intragastrically) with a two-week washout period between doses. Bioavailability of intragastric diphenhydramine was less than one percent and six percent for 1 mg/kg and 5 mg/kg intragastric doses, respectively. This poor bioavailability is similar to what is reported in dogs. Two of six horses experienced transient side effects after intravenous diphenhydramine administration, emphasizing the need for determining therapeutic plasma levels in efforts to determine the lowest effective dose minimizing risk of adverse effects. The main conclusion of our study was that oral diphenhydramine at doses up to 5 mg/kg are unlikely to achieve therapeutic plasma levels in adult horses.

Role of Patch Testing in Chronic Spontaneous Urticaria

Background

Chronic spontaneous urticaria (CSU) is a common debilitating condition. Although not completely understood, the main pathomechanism involves autoimmune-related mast-cell degranulation. Patch test (PT) is the gold standard for the diagnosis of type IV cutaneous hypersensitivity. The relevance of PT to the diagnosis of CSU is debatable.

Objective

We aimed at determining the role of PT in selected patients with CSU.

Methods

In this retrospective study, we reviewed cases of patients referred for patch testing at our clinic. We compared results of patients with CSU (n = 134) and patients with suspected allergic contact dermatitis (n = 680; control group).

Results

Among patients in the CSU group, 3% of patients had relevant reactions to PT, indicating that contact allergen avoidance resulted in resolution of all skin findings. Metals and textile dyes were the most relevant allergens. No significant differences were found between the groups with regard to the percentage of patients with positive PT and hapten reaction profiles. Patients from the CSU group were significantly older (4.1 years on average, P < 0.05), consisted of more females, and were less likely to have atopic trait (46% vs 58%, P<0.05).

Conclusion

In some of patients, PT may assist in determining the cause of CSU.

Targeted Therapy for Chronıc Spontaneous Urtıcarıa: Ratıonale and Recent Progress

Chronic spontaneous urticaria (CSU) is characterized by the presence of wheals, angioedema, or both for at least 6 weeks. It may persist for a long time-up to 50% of the patients have been reported to be symptomatic 5 years after the onset. Some patients can suffer more than one episode of CSU during their lifetime. Considering the recurrences, disabling symptoms, and significant impact on quality of life, proper and effective treatment of CSU is critical. The use of antihistamines (AHs) is still the mainstay of treatment. However, given the low rates of response to AHs (38.6% and 63.2% to standard doses and higher doses, respectively), the complete control of symptoms seems difficult to attain. The use of omalizumab for CSU has been a major breakthrough in the care of patients with CSU. However, the partial response and lack of response to omalizumab in a subgroup of patients, as high as 70% in some studies, make the development of alternative treatments desirable. Ever-increasing knowledge on the pathogenesis is making new target molecules available and enabling drug development for CSU. In addition to drug repurposing as in anti-IL-4/13, IL-5, and IL-17 antibodies, novel targeted therapy options such as ligelizumab and Bruton's tyrosine kinase inhibitors are currently undergoing clinical trials and will be available in the near future. This article reviews the current challenges in the treatment of CSU, the pathogenesis and potential target molecules, and the rationale for novel treatments and their rapidly developing status.

The Role of Coagulation and Complement Factors for Mast Cell Activation in the Pathogenesis of Chronic Spontaneous Urticaria

Chronic spontaneous urticaria (CSU) is a common skin disorder characterized by an almost daily recurrence of wheal and flare with itch for more than 6 weeks, in association with the release of stored inflammatory mediators, such as histamine, from skin mast cells and/or peripheral basophils. The involvement of the extrinsic coagulation cascade triggered by tissue factor (TF) and complement factors, such as C3a and C5a, has been implied in the pathogenesis of CSU. However, it has been unclear how the TF-triggered coagulation pathway and complement factors induce the activation of skin mast cells and peripheral basophils in patients with CSU. In this review, we focus on the role of vascular endothelial cells, leukocytes, extrinsic coagulation factors and complement components on TF-induced activation of skin mast cells and peripheral basophils followed by the edema formation clinically recognized as urticaria. These findings suggest that medications targeting activated coagulation factors and/or complement components may represent new and effective treatments for patients with severe and refractory CSU.

Systemic and local evidence for complement involvement in chronic spontaneous urticaria

Background

The pathogenesis of chronic spontaneous urticaria (CSU), including the mechanism of action of omalizumab, remain unclear. We hypothesized complement system involvement given the often fast clinical response induced by treatment, including omalizumab. Therefore, we assessed the role of various complement factors surrounding omalizumab treatment.

Methods

Thirty CSU patients (median age 42 [range 21-70]; 73 % female) with a median once daily Urticaria Activity Score over 7 days (UAS7) score at baseline of 31.5 points were enrolled. Treatment consisted of six administrations of 300 mg omalizumab every 4 weeks succeeded by a follow-up period of 12 weeks. Four punch skin biopsies were taken per patient; at baseline from lesional skin, at baseline from nonlesional skin, and after 1 and 7 days from formerly lesional skin. Complement activity, including C1q, C3, C3bc/C3, C4, C4bc/C4, C5a, and Membrane Attack Complex in peripheral blood were analyzed and complement activation in the skin was determined by the analysis of C4d deposition. Results were related to the clinical response to omalizumab.

Results

Fifteen patients showed a UAS7 score of 6 or lower (median 0) at Week 24, 15 patients did not (median 16). Lesional skin biopsies at baseline revealed complement deposition (C4d) in blood vessels in the papillary dermis of 53% (16/30) of the patients, which suggests involvement of immune complexes in the pathogenesis of urticaria. Moreover, indication of increased complement activation in CSU was substantiated by increased C5a levels in peripheral blood compared to healthy controls (p = 0.010). The clinical effect of omalizumab could not be linked to the variation of complement components.

Conclusions

Both C4d deposition in lesional skin and elevated C5a levels in peripheral blood indicate the involvement of complement activation in the pathogenesis of CSU. No correlation was found between omalizumab and activation of complement indicative of independent processes in the immunopathogenesis of CSU.

Biologics for the Use in Chronic Spontaneous Urticaria: When and Which

Guidelines for the treatment of chronic spontaneous urticaria (CSU) recommend the use of the IgE-targeted biologic omalizumab in patients with antihistamine-refractory disease. The rationale for this is supported by the key role of IgE and its high-affinity receptor, FcεRI, in the degranulation of skin mast cells that drives the development of the signs and symptoms of CSU, itchy wheals, and angioedema. Here, we review the current understanding of the pathogenesis of CSU and its autoimmune endotypes. We describe the mechanisms of action of omalizumab, the only biologic currently approved for CSU, its efficacy and ways to improve it, biomarkers for treatment response, and strategies for its discontinuation. We provide information on the effects of the off-label use, in CSU, of biologics licensed for the treatment of other diseases, including dupilumab, benralizumab, mepolizumab, reslizumab, and secukinumab. Finally, we discuss targets for novel biologics and where we stand with their clinical development. These include IgE/ligelizumab, IgE/GI-310, thymic stromal lymphopoietin/tezepelumab, C5a receptor/avdoralimab, sialic acid-binding Ig-like lectin 8/lirentelimab, CD200R/LY3454738, and KIT/CDX-0159. Our aim is to provide updated information and guidance on the use of biologics in the treatment of patients with CSU, now and in the near future.

Epidemiology of urticaria in German children

BACKGROUND

To date, robust epidemiological metrics as well as data on comorbidity in pediatric urticaria are lacking. They form the basis for the design of efficient healthcare.

METHODS

Retrospective study to analyze epidemiological data in pediatric urticaria. The analysis is based on routine data of a health insurance company operating throughout Germany (DAK-Gesundheit). Insured people under 18 years of age who received at least one confirmed outpatient or inpatient urticaria diagnosis according to the ICD-10 classification in the years 2010 to 2015 were included in the analysis and compared to children without a corresponding diagnosis.

RESULTS

Of 2.3 million insured individuals, 313,581 (13.5 %) were under 18 years of age (153,214 female). Urticaria was diagnosed in 1.7 % of the 313,581 patients. The prevalence of urticaria decreased with age from 3.0 % in the 0-3-year age group to 1.0 % in the 14-18-year age group. Boys and girls were almost equally affected in all age groups. Atopic diseases as comorbidity occurred more frequently in children with urticaria than in the control group (16.0 % vs. 8.0 %). Autoimmune diseases, mental health problems, and obesity also occurred more frequently in children with urticaria than in the control group.

CONCLUSIONS

The increased prevalence of specific comorbidities in children with urticaria suggests an increased need for screening. Multimodal treatment strategies need to be developed and interdisciplinary collaboration promoted.

Approach to Children with Hives

Urticaria (or hives) is a pruritic and erythematous skin rash. Angioedema commonly occurs with urticaria. The term "chronic urticaria" is used when hives are present for more than 6 weeks. Acute urticaria is common in children, whereas chronic urticaria is rare. Causes of urticaria can be identified in many cases of acute urticaria with a thorough medical history. Laboratory evaluation may be needed to confirm the etiology of acute urticaria. Chronic urticaria is often idiopathic. Clinicians should avoid universal allergy testing for food allergens or aeroallergens in chronic urticaria as it usually does not help in identifying the cause, can lead to false-positive results, and unnecessary avoidance of allergens or foods. Urticarial vasculitis should be considered for lesions that are painful, present for more than 48 hours, leave scars/hyperpigmentation, or present with systemic symptoms such as fever, weight loss, and arthritis. Skin biopsy should be considered for suspected urticarial vasculitis. [Pediatr Ann. 2021(5):e191-e197.].

Biomarkers of chronic spontaneous urticaria and their clinical implications

Introduction: Chronic spontaneous urticaria (CSU) is a frequent disorder in which activation of effector cells and histamine release can be induced via several distinct pathogenetic mechanisms. Much work has been carried out to identify biomarkers useful for classifying CSU patients, and to predict their response to currently available treatments.Areas covered: The recent literature dealing with CSU biomarkers was screened in PubMed and Google Scholar using 'chronic spontaneous urticaria', 'biomarker', 'diagnosis', 'therapy' and 'treatment response' as key words. The characteristics found in relevant papers were divided into clinical and serological biomarkers of (a) clinical severity/disease activity, and (b) response to treatments.Expert opinion: A diagnostic biomarker for CSU is still missing. Most biomarkers described so far do not seem to possess sufficient specificity for this disease. Basopenia and the activation of the coagulation cascade might be biomarkers of disease activity and severity, but information available so far is insufficient to consider their routine use. Markers suggesting IgG-mediated autoimmunity (autologous serum skin test, basophil activation/histamine release assays, low total IgE) seem to identify patients less prone to respond to omalizumab but responsive to cyclosporine. In contrast, 'autoallergy' (i.e. the presence of IgE to autoallergens), which is often associated with elevated IgE levels seems to identify patients who will respond to omalizumab.

Effects of omalizumab on basophils: Potential biomarkers in asthma and chronic spontaneous urticaria

Omalizumab is an anti-IgE humanized monoclonal antibody approved for the treatment of severe asthma and chronic spontaneous urticaria. Omalizumab binds free serum IgE and antagonizes its interaction with FcεRI, which is considered the main pharmacodynamic mechanism responsible for the clinical response to the treatment. The reduction of IgE serum concentration down-regulates the cellular expression of FcεRI on basophils. However, the biological events occurring on basophils during the therapy with omalizumab are multiple and complex. Here we review the current evidence regarding the specific biological effects of omalizumab on basophils in patients with asthma and chronic spontaneous urticaria. In addition to the modulation of IgE receptors, omalizumab may affect basophils homeostasis, intra-cellular signaling, cellular responsiveness/activation and cytokine release. These effects may be partially responsible for the clinical success of omalizumab and potentially provide useful biological markers for future assessment of the clinical response to the treatment. However, further investigation is required to better elucidate the role of basophils during the treatment with omalizumab.

Current and Potential Biologic Drugs for the Treatment of Chronic Urticaria

This article reviews biologic treatments that are currently applied for the treatment of severe chronic urticaria. Monoclonal anti-immunoglobulin E (omalizumab) is effective and safe in many patients, but accessibility and cost constitute barriers to its wider use. Questions on the optimal duration of the treatment and possible symptom recurrences after discontinuing the drug are still raised. A discussion is presented about several other biologics currently under investigation with potential to be incorporated in the near future in patients with severe chronic urticaria.

The association between chronic spontaneous urticaria and HLA class I and class II antigen

Background/aim

Chronic spontaneous urticaria (CSU) is a chronic disease with an unknown etiology. In human leukocyte antigen (HLA) system, the association of class I and class II antigens with autoimmune diseases has been identified and HLA antigens that have a tendency to or can prevent chronic urticaria have been studied. The aim of this study is to investigate the association between chronic spontaneous urticaria and HLA class I and class II antigens.

Materials and methods

A total of 80 subjects, 40 patients with CSU and 40 healthy individuals were enrolled in the study. DNA sample isolation from blood was primarily done by the real-time polymerase chain reaction (RT-PCR) technique for the first time. Using HLA SSP Typing Kit (ROSE Cat. No: 800118) PCR technique, HLA-A, B, C, DRB and DQB alleles from DNA samples were analyzed.

Results

The mean age was 36.80 ± 9.48 years and the duration of the disease was 4.26 ± 5.18 years. Among the HLA class I and class II antigens, HLA-A was detected significantly more often in the control group (P = 0.039). HLA-DRB1 was more often detected in the CSU group but no statistical difference (P > 0.05).

Conclusion

It can be considered that HLA-DRB1 may have a tendency to CSU, while HLA-A might prevent the disease.

Canakinumab Lacks Efficacy in Treating Adult Patients with Moderate to Severe Chronic Spontaneous Urticaria in a Phase II Randomized Double-Blind Placebo-Controlled Single-Center Study

BACKGROUND

Chronic idiopathic/spontaneous urticaria (CSU) is a common disease with a significant proportion of patients who do not respond to standard therapy with antihistamines and optionally corticosteroids/immunosuppressants.

OBJECTIVE

The IL-1β antagonist canakinumab is effective in cryopyrin-associated periodic syndromes associated with urticarial symptoms and urticarial vasculitis, and so it was suspected that it could also be effective in patients with CSU.

METHODS

The effect of canakinumab was investigated in 20 patients with moderate to severe CSU in a 1:1 randomization to either canakinumab or placebo in a double-blind single-dose crossover design. The verum group received 150 mg canakinumab subcutaneously once at baseline. Patients who had received placebo were able to switch to canakinumab at week 4 if they did not improve. The primary end point was clinical improvement at week 4 compared with baseline in sum of urticaria activity scores over 7 consecutive days. Secondary end points were the clinical improvement at week 8 compared with baseline in sum of urticaria activity scores over 7 consecutive days and the clinical improvement measured by the Physician Score and Dermatology Life Quality Index at week 1, 2, 4, and 8.

RESULTS

At week 4, 2 patients with canakinumab and 3 with placebo met the primary end point, and so canakinumab failed the significant superiority to the placebo (P = 1.0). An inclusion of the patients who switched to canakinumab after 4 weeks did not alter the result. There was also no significant difference between the verum and placebo groups for all secondary end points. The therapy was well tolerated, and mild adverse events were equally distributed between verum and placebo groups.

CONCLUSIONS

Because of this clinical trial with 20 patients, it must be assumed that canakinumab has no effect on lesions of CSU. This suggests that IL-1β may not play a crucial role in pathology of patients with CSU, unlike, for example, in hereditary fevers or urticarial vasculitis, where targeting IL-1 is a main treatment option. However, the good tolerability of canakinumab could be confirmed.

Treatment of urticaria: a clinical and mechanistic approach

PURPOSE OF REVIEW

This manuscript describes the recommended therapy of chronic spontaneous urticaria based on our understanding of the pathogenesis of hive formation. Thus, the mechanism of action of each medication is elaborated in addition to a discussion of clinical utility.

RECENT FINDINGS

The main drugs are antihistamines, omalizumab, and cyclosporine with a success rate of 40-55, 65-80, and 70-80%, respectively. Used in sequence, over 90% of patients can be successfully treated. The addition of omalizumab represents a major advance because of its efficacy, easy utility, and favorable side-effect profile. The interaction with IgE eliminates any reaction with antigens to which it might be directed, down regulates IgE receptors on mast cells and basophils, and leads to down-regulation of mast cell functions with amelioration of hives.

SUMMARY

The use of antihistamines in high dosage (at least four times a day) is effective in close to half the patients with CSU. For antihistamine resistance, the use of omalizumab has revolutionized therapy of antihistamine-resistant cases because of its efficacy and excellent side-effect profile. If the response is insufficient, cyclosporine is the next choice. Patients should be monitored regarding any adverse effects on blood pressure or renal function. All these are far safer than extended use of corticosteroid.

Efficacy and safety of active vitamin D supplementation in chronic spontaneous urticaria patients

Background: Chronic spontaneous urticaria (CSU) is a common skin disorder affecting negatively patients' lives. Vitamin D deficiency has been reported to be associated to many allergic skin disorders.Objective: This study aimed to evaluate the association between the serum level of 25 hydroxy vitamin D and CSU and to assess the efficacy and safety of active vitamin D in management of CSU.Methods: The study was conducted on 77 patients with CSU and 67 healthy controls, then the 77 CSU patients were randomized to either the study group that received 0.25 µg alfacalcidol daily or the placebo group that received oral placebo for 12 weeks.Results: Serum 25(OH) D was significantly lower in CSU as compared to healthy controls and was negatively correlated to the urticarial severity. After alfacalcidol administration, the study group showed significant higher level of 25(OH) D compared to the placebo group. In addition, the mean serum level of IL6, hsCRP and TNFα significantly decreased in the study group in comparison to the placebo group and as compared to their baseline results.Conclusion: Vitamin D deficiency is more common in CSU patients as compared to healthy people and hence, alfacalcidol might have a beneficial role as add on therapy in CSU management with no reported side effects.

Urticaria: recommendations from the Italian Society of Allergology, Asthma and Clinical Immunology and the Italian Society of Allergological, Occupational and Environmental Dermatology

Background

Urticaria is a disorder affecting skin and mucosal tissues characterized by the occurrence of wheals, angioedema or both, the latter defining the urticaria-angioedema syndrome. It is estimated that 12–22% of the general population has suffered at least one subtype of urticaria during life, but only a small percentage (estimated at 7.6–16%) has acute urticaria, because it is usually self-limited and resolves spontaneously without requiring medical attention. This makes likely that its incidence is underestimated. The epidemiological data currently available on chronic urticaria in many cases are deeply discordant and not univocal, but a recent Italian study, based on the consultation of a national registry, reports a prevalence of chronic spontaneous urticaria of 0.02% to 0.4% and an incidence of 0.1–1.5 cases/1000 inhabitants/year.

Methods

We reviewed the recent international guidelines about urticaria and we described a methodologic approach based on classification, pathophysiology, impact on quality of life, diagnosis and prognosis, differential diagnosis and management of all the types of urticaria.

Conclusions

The aim of the present document from the Italian Society of Allergology, Asthma and Clinical Immunology (SIAAIC) and the Italian Society of Allergological, Occupational and Environmental Dermatology (SIDAPA) is to provide updated information to all physicians involved in diagnosis and management of urticaria and angioedema.

Chronic Spontaneous Urticaria: A Review of Pathological Mechanisms, Diagnosis, Clinical Management, and Treatment

Urticaria is a poorly understood and underestimated clinical condition characterised by the sudden onset of itchy wheals and/or angioedema, which usually resolve within 24 and 72 hours, respectively. It is generally classified as being acute (lasting <6 weeks) or chronic (continuous or intermittent for ≥6 weeks). Chronic urticaria can be further classified as chronic spontaneous urticaria (CSU) and chronic inducible urticaria, appearing in response to specific eliciting factors, such as heat, cold, or sun exposure, or following the application of pressure. Scientific advances have been made in the understanding of pathological mechanisms and treatment, especially associated with CSU. The exact pathological mechanism of how urticaria develops is still not yet fully understood, but the clinical implications on the patients’ quality of life are severe and have been associated with mental disorders and metabolic diseases. The diagnosis of urticaria is based on medical history and clinical manifestations. The treatment pathway begins with the administration of second-generation, nonsedating, nonimpairing histamine 1 receptor antihistamines and, in case of nonresponse, with new-generation biological drugs. The current review presents an update of the pathological mechanisms, diagnosis, clinical management, and treatment of CSU. It also focusses on the future implications of new-generation drugs and their effects on the clinical practice.

Risk of Urticaria in Children with Type 1 Diabetes Mellitus: A Nationwide Cohort Study

Type 1 diabetes mellitus (T1DM) has been linked to many autoimmune problems. The association between T1DM and urticaria warrants investigation. Data were extracted from the National Health Insurance Research Database (NHIRD) of Taiwan. Participants with T1DM were recruited as the case group, and that group was matched by sex and age at a ratio of 1:4 to the control group comprising those without T1DM. The study period was 1998–2011. All participants were followed up to the diagnosis of urticaria, withdrawal from the insurance program, death, or the end of the study. A multivariable Cox proportional hazard model was used to calculate the adjusted and crude hazard ratios for urticaria. A total of 5895 participants (1179 in the case group and 4716 in the control group) were followed up in the study. The total incidence rate of urticaria in patients with type 1 DM was 26.6 per 1000 person-years, and that in controls was 6.85 per 1000 person-years. Compared with the control group, the hazard ratio of urticaria in the case group was 2.84 (95% CI = 2.27–3.56). Compared with age-matched participants without T1DM, patients with type 1 DM aged <18 years had a 3.62-fold higher risk of urticaria (95% CI = 2.85–4.59). The hazard ratio in patients with an adjusted Diabetes Complications Severity Index (aDCSI) score of 1.01–2.00 per year was 2.57 (95% CI = 1.18–5.57), and that in patients with an aDCSI score of >2.00 per year was 4.47 (95% CI = 2.68–7.47). T1DM patients aged <18 years had an increased risk of urticaria, but a similar phenomenon was not observed among T1DM patients older than 18 years.

Biomarkers In Chronic Spontaneous Urticaria: Current Targets And Clinical Implications

Chronic urticaria (CU) is a mast cell-driven disease characterized by the development of wheals, angioedema, or both for more than 6 weeks. The two major sub-types are chronic spontaneous urticaria (CSU) and inducible urticaria. In the last decade different pathophysiological mechanisms, potentially responsible for the development of the disease, have been described. It is likely that the activation of mast cells and basophils in CSU can be the results of immune system dysregulation, activation of the inflammatory cascade, and of the extrinsic coagulation pathway. Some of the mediators involved in the pathophysiological mechanisms of CSU have recently been identified as potential biomarkers useful for the diagnosis, follow-up, and management of the disease, even if they are not yet available in clinical practice. Thus, in this review we discuss new insights in the mediators involved in the pathogenesis of CSU, highlighting their potential role as biomarkers in the activity and progression of the disease and response to therapies.

Somatic Mosaic NLRP3 Mutations and Inflammasome Activation in Late-Onset Chronic Urticaria

Chronic urticaria is a common skin disorder with heterogeneous causes. In the absence of physical triggers, chronic urticarial rash is called idiopathic or spontaneous. The objective of this study was to identify the molecular and cellular bases of a disease condition displayed by two unrelated patients aged over 60 years who presented for two decades with a chronic urticaria resistant to standard therapy that occurred in the context of systemic inflammation not triggered by cold. In both patients, a targeted sequencing approach using a next generation technology identified somatic mosaic mutations in NLRP3, a gene encoding a key inflammasome component. The study of several of both patients' cell types showed that, despite the late onset of the disease, NLRP3 mutations were not found to be restricted to myelomonocytic cells. Rather, the data obtained strongly suggested that the mutational event occurred very early, during embryonic development. As shown by functional studies, the identified mutations-an in-frame deletion and a recurrent NLRP3 missense mutation-have a gain-of-function effect on NLRP3-inflammasome activation. Consistently, a complete remission was obtained in both patients with anti-IL-1 receptor antagonists. This study unveils that in late-onset chronic urticaria, the search for autoinflammatory markers and somatic mosaic NLRP3 mutations may have important diagnostic and therapeutic consequences.

Autologous whole-blood or autologous serum acupoint injection therapy for chronic urticaria: A systematic review protocol

BACKGROUND

Chronic urticaria (CU) is a common and easily recurring skin disease in the world. Many trials have shown that autologous whole-blood or autologous serum acupoint injection therapy is effective in treating CU. There is currently no systematic review of this therapy. The program aims to evaluate the effectiveness and safety of this therapy in patients with CU.

METHODS

Literature search will be conducted at Medline, PubMed, Excerpt Medica Database, Springer, Web of Science, Cochrane Library, China National Knowledge Infrastructure, Chinese Scientific Journal Database, and other databases. The search date is until May 2019. We will search for popular terms including CU and this therapy. Import the literature electronically. Duplicate documents will be deleted. The primary outcome is the urticaria activity score or other validated scales. Secondary outcomes included response rate, quality of life scale, recurrence rate, and adverse events. A systematic review and search for a randomized controlled trial of this therapy for CU. Implement the Cochrane RevMan V5.3 bias assessment tool to assess bias assessment risk, data integration risk, meta-analysis risk, and subgroup analysis risk (if conditions are met). The mean difference, standard MD, and binary data will be used to represent continuous results.

RESULTS

This study will provide a comprehensive review of the available evidence for the treatment of CU with this therapy.

CONCLUSION

This study will provide new evidence for assessing the effectiveness and side effects of this therapy for CU. Since the data is not individualized, there is no need for formal ethical approval.

PROSPERO REGISTRATION NUMBER

CRD42019128364.

Suppression of IgE-Independent Degranulation of Murine Connective Tissue-Type Mast Cells by Dexamethasone

Steroidal anti-inflammatory drugs are widely used for the treatment of chronic cutaneous inflammation, such as atopic dermatitis, although it remains unknown how they modulate cutaneous mast cell functions. We investigated the effects of prolonged treatment with a synthetic glucocorticoid, dexamethasone, on murine connective tissue-type mast cells using in vitro and in vivo models. Our connective tissue-type bone marrow-derived cultured mast cell model was found to be sensitive to mast cell secretagogues, such as compound 48/80 and substance P, and higher expression levels of α subunit of a trimeric G protein, G_i1, and several Mas-related G protein-coupled receptor (Mrgpr) subtypes were observed in comparison with immature cultured mast cells. Secretagogue-induced degranulation and up-regulation of these genes was suppressed when cultured in the presence of dexamethasone. The profiles of granule constituents were drastically altered by dexamethasone. Topical application of dexamethasone down-modulated secretagogue-induced degranulation and the expression levels of several Mrgpr subtypes in cutaneous tissue. These results suggest that mast cell-mediated IgE-independent cutaneous inflammation could be suppressed by steroidal anti-inflammatory drugs through the down-regulation of G _αi1 and several Mrgpr subtypes in mast cells.

Relevance of the Basophil High-Affinity IgE Receptor in Chronic Urticaria: Clinical Experience from a Tertiary Care Institution

BACKGROUND

The high-affinity IgE receptor (FcεRI) expression on effector cells has been poorly characterized in patients with chronic urticaria (CU) to date.

OBJECTIVES

To investigate the FcεRI expression on blood basophils in a large cohort of patients with CU and its potential relationship with relevant features of the disease.

METHODS

Basophil FcεRI expression was measured by flow cytometry in 287 patients with CU (192 with chronic spontaneous urticaria and 95 with chronic inducible urticaria) at their initial evaluation in our department. A control group of healthy nonatopic individuals was included to provide reference data, and the effect of antihistamine and anti-IgE therapy on the basophil FcεRI expression was also evaluated in a cohort of patients with CU.

RESULTS

The median FcεRI expression was found significantly higher in patients with CU compared with healthy controls (P < .0001). A positive correlation was found between serum IgE levels and basophil FcεRI expression (R = 0.422; P < .001). Significantly higher FcεRI levels on basophils were detected in patients with CU who presented with concomitant atopic features (P = .003), negative autologous serum skin test (P = .002), negative autologous plasma skin test (P = .009), or undetected levels of antithyroid antibodies (P = 0.01). Baseline FcεRI expression was not related to the activity and duration of the disease, and was not significantly modified during antihistamine therapy; however, it correlated with the clinical response to omalizumab (P = .003).

CONCLUSIONS

Although further multicenter studies are needed to corroborate these findings, the assessment of basophil FcεRI levels might be relevant in daily clinical practice supporting an autoimmune pathogenesis and predicting response to anti-IgE treatment.

Relationship between Chronic urticaria and autoimmune thyroid disease

Hives is an erythematous and itchy disease that commonly affects the trunk and the organs. Acute urticaria is a common disease and affects about 10%-20% of the population during its lifetime. In patients with chronic urticaria, about 25%-30% of cases, antithyroid peroxidase (TPO) was detected and Hashimoto's disease was diagnosed. This study aimed to evaluate the anti-TPO antibody in patients with chronic urticaria and the effect of treatment of levothyroxine on its recovery. In this study, 72 people with chronic urticaria and positive anti-TPO antibody were randomly divided into two groups. Low-dose antihistamine was administered to both groups, and the first group received levothyroxine at a dose of 50 μg/day. The severity of itching was evaluated according to the visual analog scale before and after therapy. There was no significant difference in the age, sex, thyroid-stimulating hormone (TSH), and anti-TPO between the two groups. Ninety-two patients were female. In this study, all patients took a small dose of loratadine. Relative healing was observed in both the groups. However, in a group of patients taking levothyroxine and loratadine, recovery was faster and patients with no itching were significantly more likely than the other groups. The prevalence of chronic urticaria and anti-TPO antibody in this study was very high and was due to sex hormones. Therefore, in young women with chronic urticaria, especially in refractory cases, they should be monitored for anti-TPO. Anti-TPO and TSH should be evaluated for the diagnosis and treatment of patients with urticaria or chronic angioedema. Levothyroxine therapy in hives and chronic urticaria is beneficial in the treatment of thyroid dysfunction.

Human eosinophils and mast cells: Birds of a feather flock together

While the origin of the phrase "birds of a feather flock together" is unclear, it has been in use for centuries and is typically employed to describe the phenomenon that people with similar tastes or interests tend to seek each other out and congregate together. In this review, we have co-opted this phrase to compare innate immune cells of related origin, the eosinophil and mast cell, because they very often accumulate together in tissue sites under both homeostatic and inflammatory conditions. To highlight overlapping yet distinct features, their hematopoietic development, cell surface phenotype, mediator release profiles and roles in diseases have been compared and contrasted. What emerges is a sense that these two cell types often interact with each other and their tissue environment to provide synergistic contributions to a variety of normal and pathologic immune responses.

Intravenous immunoglobulin induces IL-4 in human basophils by signaling through surface-bound IgE

BACKGROUND

Therapeutic normal IgG or intravenous immunoglobulin (IVIG) exerts anti-inflammatory effects through several mutually nonexclusive mechanisms. Recent data in mouse models of autoimmune disease suggest that IVIG induces IL-4 in basophils by enhancing IL-33 in SIGN-related 1-positive innate cells. However, translational insight on these data is lacking.

OBJECTIVE

We sought to investigate the effect of IVIG on human basophil functions.

METHODS

Isolated circulating basophils from healthy donors were cultured in the presence of IL-3, IL-33, GM-CSF, thymic stromal lymphopoietin, or IL-25. The effect of IVIG and F(ab')₂ and Fc IVIG fragments was examined based on expression of various surface molecules, phosphorylation of spleen tyrosine kinase, induction of cytokines, and histamine release. Basophil phenotypes were also analyzed from IVIG-treated patients with myopathy. Approaches, such as depletion of anti-IgE reactivity from IVIG, blocking antibodies, or inhibitors, were used to investigate the mechanisms.

RESULTS

We report that IVIG directly induces activation of IL-3-primed human basophils, but IL-33 and other cytokines were dispensable for this effect. Activation of basophils by IVIG led to enhanced expression of CD69 and secretion of IL-4, IL-6, and IL-8. IVIG-treated patients with myopathy displayed enhanced expression of CD69 on basophils. The spleen tyrosine kinase pathway is implicated in these functions of IVIG and were mediated by F(ab')₂ fragments. Mechanistically, IVIG induced IL-4 in human basophils by interacting with basophil surface-bound IgE but independent of FcγRII, type II Fc receptors, C-type lectin receptors, and sialic acid-binding immunoglobulin-like lectins.

CONCLUSION

These results uncovered a pathway of promoting the T_H2 response by IVIG through direct interaction of IgG with human basophils.

Thyroid diseases and skin autoimmunity

The skin is the largest organ of the body, at the boundary with the outside environment. Primarily, it provides a physical and chemical barrier against external insults, but it can act also as immune organ because it contains a whole host of immune-competent cells of both the innate and the adaptive immune systems, which cooperate in eliminating invading pathogens following tissue injury. On the other hand, improper skin immune responses lead to autoimmune skin diseases (AISD), such as pemphigus, bullous pemphigoid, vitiligo, and alopecia. Although the interplay among genetic, epigenetic, and environmental factors has been shown to play a major role in AISD etiology and progression, the molecular mechanisms underlying disease development are far from being fully elucidated. In this context, epidemiological studies aimed at defining the association of different AISD with other autoimmune pathologies revealed possible shared molecular mechanism(s) responsible for disease progression. In particular, over the last decades, a number of reports have highlighted a significant association between thyroid diseases (TD), mainly autoimmune ones (AITD), and AISD. Here, we will recapitulate the epidemiology, clinical manifestations, and pathogenesis of the main AISD, and we will summarize the epidemiological evidence showing the associations with TD as well as possible molecular mechanism(s) underlying TD and AISD pathological manifestations.

Quercetin inhibits Mrgprx2-induced pseudo-allergic reaction via PLCγ-IP3R related Ca2+ fluctuations

An allergic reaction is a potentially fatal hypersensitivity response caused by mast cell activation, particularly histamine and lipid mediators. Histamine release caused by reaction to drugs is considered a pseudo-allergic reaction. Quercetin is known for its anti-allergic immune effect. However, at present, its anti-pseudo-allergic effect and its mechanism are less investigated. Therefore, the purpose of this study was to evaluate the anti-pseudo-allergic effect of Quercetin in vivo and to explore the mechanism in vitro. The anti-pseudo-allergic activity of Quercetin was evaluated in vivo using a mouse model, while Quercetin mechanism of action was examined in vitro using HEK293 cells expressing Mrgprx2, a mast cell specific receptor, and LAD2 mast cell line. Our in vivo results showed that Quercetin could attenuate Evans blue leakage in the paws and hind paw thickness in C57BL/6 mice in a dose-dependent manner, and could significantly inhibit serum histamine and chemokines release. In addition, it suppressed calcium mobilization and attenuated the release of histamine and MCP-1 in peritoneal mast cells in a dose-dependent manner. Furthermore, it inhibited the vasodilation due to histamine, the release of eosinophils, and the percentage of degranulated mast cells, indicating that Quercetin antagonized mast cell mediators in vivo, histamine-induced vasodilation and eosinophil release. In vitro results showed that Quercetin reduced pseudo-allergic induced calcium influx, suppressed degranulation and chemokines release in a similar way as dexamethasone (100 μM) (mast cell stabilizer) in LAD2 mast cell line. In addition, Quercetin inhibited Mrgprx2-induced both calcium influx and pseudo-allergic reaction in HEK293 cells expressing Mrgprx2. C48/80, a histamine promoter, and Substance P (a neuropeptide) EC₅₀ was higher when combined with Quercetin compared to the EC₅₀ of these compounds alone, suggesting that Quercetin could inhibit Mrgprx2-induced pseudo-allergic reaction. Furthermore, Quercetin decreased PLCγ-IP3R signaling pathway activation induced by C48/80 in LAD2 mast cell line. In Mrgprx2 knockdown LAD2 cells, the effect of Quercetin (200 μM) reduced C48/80 induced calcium flux and the release of β‑hexosaminidase, histamine, MCP-1 and IL-8 compared with non-atopic control (NC) transfected LAD2 human mast cells, suggesting that Quercetin anti-pseudo-allergic effect was related to Mrgprx2. The docking results showed that Quercetin had a good binding affinity with Mrgprx2 similar to the one of Substance P and C48/80. Therefore, Quercetin inhibited Mrgprx2-induced pseudo-allergic reaction via PLCγ-IP3R associated Ca²⁺ fluctuations. Our results validated Quercetin as an effective small molecule inhibiting Mrgprx2-induced pseudo-allergic reaction via PLCγ-IP3R associated Ca²⁺ fluctuations, thus highlighting a potential candidate to suppress Mrgprx2 induced pseudo-allergic related diseases.

Chronic spontaneous urticaria treated with omalizumab: report of two cases

Background: Chronic spontaneous urticaria (CSU) is a relatively common skin disease whose etiopathogenesis, as well as other factors influencing disease manifestations, are not fully understood. Mast cell function is recognised as having a central role in CSU signs and symptoms. Therapeutic options are limited; a number of drugs, recommended by international guidelines for the management of urticaria, lack regulatory approval for CSU and are prescribed off label. Omalizumab, a recombinant humanized anti IgE antibody, has recently received the approval for CSU treatment in Europe after an appropriate clinical development. Patients and results: Two case reports, that describes our encouraging experience with this therapeutic option in a real-life setting are discussed and deeply investigate the different scenario for the omalizumab use. Conclusion: In both cases, a complete remission of CSU symptoms after omalizumab treatment are demonstrated. Moreover, 6 months therapy gave the better results, whit a relapse, in one subject, 1 month after discontinuing omalizumab. Accordingly, a better understanding of long-term safety and efficacy should be needed to allow long-term administration in responding patients through a changing in prescription rules.