Paradoxical Worsening of Chronic Spontaneous Urticaria Following Omalizumab Administration: The Missing Link.

Omalizumab, a humanized anti-IgE monoclonal antibody, is commonly employed in the treatment of antihistamine-refractory chronic spontaneous urticaria (CSU), where it significantly reduces free IgE levels, minimizing histamine release from basophils and mast cells. Despite its efficacy, there are concerns regarding its effect on parasitic defense due to IgE's role in combating parasitic infestations. We present a case of a 28-year-old female agriculturist with a six-month history of CSU who experienced a paradoxical exacerbation of her symptoms following an increase in the omalizumab treatment dose. This deterioration coincided with a serologically confirmed parasitic infection with Echinococcus granulosus and Toxocara canis. Despite normal eosinophil counts and IgE levels, which are typically used to identify parasitic infections, the patient's clinical worsening prompted further investigation that led to the identification of the parasitic infection. Treatment with albendazole and omalizumab discontinuation led to the resolution of her CSU, suggesting that the parasitic infection was contributing to the symptom exacerbation. This case highlights the need for careful screening for parasitic infections before initiating omalizumab in antihistamine-refractory CSU patients from endemic regions, or patients who deteriorate clinically on omalizumab, especially when other indicators such as eosinophil count and IgE levels might not suggest infection. It also underscores the importance of considering a tailored approach to managing CSU that balances effective treatment with the potential for adverse effects related to immunomodulation.

First Case of Human Anisakiosis in Greece: Acute Invasive Infection Mimicking Peritoneal Malignancy.

Consumption of raw and mildly processed seafood, in the context of modern Western world eating trends, is recognized as a major driver for human fish-borne infections. However, these zoonoses and their unfamiliar risks remain neglected and underappreciated among European diagnosticians. In contemporary Europe anisakidosis is one of the most important fish-borne zoonoses. It is caused by ingesting the third-stage infective larvae of the nematode parasites that belong to the family Anisakidae. The case described herein, is an intestinal and ectopic form of anisakiosis (Anisakis spp.), causing symptoms of subacute abdomen and masquerading as an intraperitoneal malignancy. It is the first anisakidosis case reported in Greece, affecting a young patient who had been repeatedly exposed to the parasite by consuming homemade raw fish. Right hemicolectomy, omentectomy and excision of a descending colon nodule were uneventfully performed. The pathology report confirmed granulomatous tissue with eosinophilic infiltration and parasites that were morphologically and molecularly identified as Anisakis spp. Although challenging, acquiring an accurate diagnosis of anisakidosis can prevent unnecessary surgery, as the infection typically is self-resolving, and if treatment is deemed necessary, it can be limited to antiparasitic medication. However, in rare cases, extra-gastrointestinal migration of larvae can cause severe damage with practically unknown risks, posing a diagnostic and therapeutic dilemma. In such a clinical case scenario, surgical exploration can decisively contribute to a definitive diagnosis and early identification of intraabdominal complications necessitating surgical intervention.

A systematic review and meta-analysis on nutritional and dietary interventions for the treatment of acute respiratory infection in pediatric patients: An EAACI taskforce.

Acute respiratory infections are a major cause of morbidity and mortality in children worldwide. Dietary and nutritional interventions, including minerals and vitamin supplementation, have been explored as potential treatments for these infections. However, the evidence on their efficacy is limited and inconclusive. This systematic review and meta-analysis aim to provide a comprehensive summary of the available evidence on the effectiveness of dietary and nutritional interventions for treating acute respiratory tract infections in children. A systematic review was conducted according to the PRISMA 2020 guidelines in April 2022 and updated in April 2023. Clinical trials focusing on dietary or nutritional interventions, including supplementations, in children with acute respiratory tract infections were included. The selection of interventions and outcomes was based on biological plausibility. Data were extracted using a standardized form, and the risk of bias was assessed using the Cochrane Risk of Bias Tool. Meta-analysis was performed using random-effect models. A total of 50 studies were included in the review. Four trials were conducted in low, 32 in lower-middle, 12 in upper-middle, and only two in high-income countries. The studies evaluated various dietary interventions, including zinc, vitamin A, vitamin E, vitamin D, and probiotics. The results of individual studies on the efficacy of these interventions were mixed, with some showing positive effects on clinical outcomes such as duration of symptoms, while others showed no significant impact. Meta-analysis was conducted for zinc supplementation in children with pneumonia, and the pooled results suggested a potential limited benefit in terms of reduced hospital length of stay but not time to recovery. Meta-analyses on vitamin D did not show any effect in children with pneumonia. This systematic review fills a critical gap in the literature by synthesizing the available evidence on the efficacy and safety of nutritional or dietary interventions for acute respiratory tract infections in children. The findings indicate no dietary or nutritional intervention can currently be recommended for the routine treatment of respiratory tract infections in children based on single supplement studies. The metanalysis suggests that zinc supplementation might have a beneficial effect on length of hospitalization in children with pneumonia. New studies are needed to establish more conclusive evidence for pediatric acute respiratory diseases especially for children living in a context of high-income countries.

Efficacy and safety of abrocitinib in patients with moderate-to-severe atopic dermatitis and comorbid allergies.

BACKGROUND: Abrocitinib efficacy by comorbidity status in patients with moderate-to-severe atopic dermatitis (AD) has not been previously assessed. This post hoc analysis evaluated the efficacy and safety of abrocitinib in patients with AD and allergic comorbidities. METHODS: Data were pooled from patients who received abrocitinib 200 mg, 100 mg, or placebo in phase 2b (NCT02780167) and phase 3 (NCT03349060, NCT03575871) monotherapy trials. Patients with and without allergic comorbidities (allergic asthma, rhinitis, conjunctivitis, or food allergy) were evaluated for Investigator's Global Assessment (IGA) response (clear [0] or almost clear [1]), ≥75% improvement in the Eczema Area and Severity Index (EASI-75), ≥4-point improvement in Peak Pruritus Numerical Rating Scale (PP-NRS4), and Dermatology Life Quality Index (DLQI) response (<2 with baseline score ≥2). Other outcomes were Patient-Oriented Eczema Measure (POEM), SCORing Atopic Dermatitis (SCORAD), Pruritus and Symptoms Assessment for Atopic Dermatitis (PSAAD), and treatment-emergent adverse events (TEAEs). RESULTS: Of 942 patients, 498 (53%) reported at least one allergic comorbidity (asthma only, 33%; conjunctivitis only or rhinitis only or both, 17%; food allergies only, 15%; >1 allergic comorbidity, 34%). Regardless of comorbidity status, from Week 2 to Week 12, higher percentages of patients treated with either abrocitinib dose achieved IGA 0/1, EASI-75, PP-NRS4, or DLQI 0/1 versus placebo-treated patients. Changes from baseline in POEM, SCORAD, and PSAAD were greater with abrocitinib than with placebo in patients with and without allergic comorbidities. Most TEAEs were mild or moderate. CONCLUSIONS: Efficacy and safety data support abrocitinib use to manage AD in patients with or without allergic comorbidities.

EAACI guidelines on the diagnosis of IgE-mediated food allergy.

This European Academy of Allergy and Clinical Immunology guideline provides recommendations for diagnosing IgE-mediated food allergy and was developed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. Food allergy diagnosis starts with an allergy-focused clinical history followed by tests to determine IgE sensitization, such as serum allergen-specific IgE (sIgE) and skin prick test (SPT), and the basophil activation test (BAT), if available. Evidence for IgE sensitization should be sought for any suspected foods. The diagnosis of allergy to some foods, such as peanut and cashew nut, is well supported by SPT and serum sIgE, whereas there are less data and the performance of these tests is poorer for other foods, such as wheat and soya. The measurement of sIgE to allergen components such as Ara h 2 from peanut, Cor a 14 from hazelnut and Ana o 3 from cashew can be useful to further support the diagnosis, especially in pollen-sensitized individuals. BAT to peanut and sesame can be used additionally. The reference standard for food allergy diagnosis is the oral food challenge (OFC). OFC should be performed in equivocal cases. For practical reasons, open challenges are suitable in most cases. Reassessment of food allergic children with allergy tests and/or OFCs periodically over time will enable reintroduction of food into the diet in the case of spontaneous acquisition of oral tolerance.

Citrin: a novel food allergen in citrus seeds and citrus-derived pectin that shows cross-reactivity with cashew and pistachio.

BACKGROUND: Patients exquisitely sensitive to cashew/pistachio are at risk for allergic reactions to citrus seeds and pectin. OBJECTIVE: In this study, we sought to evaluate whether pectin is contaminated with citrus seeds, to identify a culprit antigen in citrus seeds, and to assess for cross-reactivity among allergens in citrus seeds, citrus pectin, and cashew or pistachio. METHODS: Proteins from orange seed coats, orange seed endosperms, lemon seeds, grapefruit seeds, citrus pectin, apple pectin, and grapefruit pectin were extracted. Protein concentrations in all extracts were determined and visualized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique. Immunoglobulin E-binding capacity was determined with Western blot analyses and tandem mass spectrometry for the identification of the culprit allergen in citrus seeds and pectin. RESULTS: In subjects with citrus seed, pectin, and cashew allergies, there was strong immunoglobulin E-reactivity to bands between 17 to 28 kDa and 28 to 38 kDa. The tandem mass spectrometry analysis of these bands indicated the presence of citrin as the culprit allergen. Citrin and Ana o 2 are both 11S globulins belonging to the cupin superfamily, and significant homology was found between these proteins. CONCLUSION: Citrus pectin may be contaminated with citrus seeds. Citrin, a newly identified allergen in citrus seeds, seems to be the culprit antigen in citrus seeds and contaminated citrus pectin. Citrin is highly homologous with Ana o 2 in cashew and Pis v 2 in pistachio, suggesting potential for cross-reactivity and providing an explanation for co-allergenicity of cashew or pistachio, citrus seeds, and citrus pectin.

Targeting Epithelium Dysfunction and Impaired Nasal Biofilms to Treat Immunological, Functional, and Structural Abnormalities of Chronic Rhinosinusitis.

Chronic rhinosinusitis (CRS) with (CRSwNP) or without (CRSsNP) nasal polyps is a prevalent and heterogeneous disorder existing as a spectrum of clinical conditions with complex underlying pathomechanisms. CRS comprises a broad syndrome characterized by multiple immunological features involving complex interactions between the genes, the microbiome, host- and microbiota-derived exosomes, the epithelial barrier, and environmental and micromilieu exposures. The main pathophysiological feature is an epithelial barrier disruption, accompanied by microbiome alterations and unpredictable and multifactorial immunologic overreactions. Extrinsic pathogens and irritants interact with multiple epithelial receptors, which show distinct expression patterns, activate numerous signaling pathways, and lead to diverse antipathogen responses. CRSsNP is mainly characterized by fibrosis and mild inflammation and is often associated with Th1 or Th17 immunological profiles. CRSwNP appears to be associated with moderate or severe type 2 (T2) or Th2 eosinophilic inflammation. The diagnosis is based on clinical, endoscopic, and imaging findings. Possible CRS biomarkers from the peripheral blood, nasal secretions, tissue biopsies, and nasally exhaled air are studied to subgroup different CRS endotypes. The primary goal of CRS management is to maintain clinical control by nasal douching with isotonic or hypertonic saline solutions, administration of nasal and systemic steroids, antibiotics, biologic agents, or, in persistent and more severe cases, appropriate surgical procedures.

Omalizumab prevents respiratory illnesses in non-atopic chronic spontaneous urticaria patients: A prospective, parallel-group, pilot pragmatic trial.

BACKGROUND: Omalizumab is the recommended treatment for antihistamine-refractory chronic spontaneous urticaria (CSU) and severe allergic asthma. In addition, it has been shown to reduce the frequency of viral respiratory infections in allergic asthma. Respiratory illness is a known trigger for asthma and CSU. OBJECTIVES: To explore whether the antiviral effect of omalizumab may be extended to CSU patients independent of their atopic status. METHODS: We conducted a prospective parallel-group pilot pragmatic trial including 30 non-allergic and non-atopic CSU patients (cases) under omalizumab 300 mg Q4-weeks (due to refractory to H1-antihistamines) and 30 age-matched healthy controls. All CSU patients had to have a weekly urticaria activity score UAS7 <15 at least 4 weeks before recruitment. Using the self-filled validated Jackson scale, we evaluated all study participants for common cold symptoms. All cases and controls rated weekly their respiratory symptoms. An increase in the symptom score of at least 4 points compared to baseline (defined as the minimum weekly report of symptoms) was considered an episode suggestive of a viral infection of the upper respiratory tract (URT). The patients were follow-up every 4 weeks throughout the study period (10 months). RESULTS: CSU patients under omalizumab reported fewer episodes suggestive of an URT viral infection than the healthy controls (median of reported episodes: 0 vs. 1, inter-quartile range 0-1 vs. 1-1, min-max: 0-3 vs. 0-4, respectively; p = 0.0095). The duration of each episode was the same in both cases and controls. CONCLUSIONS: Omalizumab can reduce the number of common cold episodes in CSU patients and consequently may minimize viral-related CSU exacerbations. This beneficial effect is exerted independently of the atopic status, even in non-asthmatic individuals or non-allergic patients without any evidence of respiratory susceptibility. Further large-scale studies are needed to validate the current findings and elucidate the underlying relevant pathophysiology.

Urticaria and Angioedema: Understanding Complex Pathomechanisms to Facilitate Patient Communication, Disease Management, and Future Treatment.

Chronic spontaneous urticaria (CSU) is primarily a T2-dominant disease with a complex genetic background. Skin mast cell activation can be induced not only via the IgE-FcεRI axis but also from several other distinct mechanisms, molecules, and receptors involved in CSU onset, persistence, and exacerbation. These include autoallergy, autoimmunity, central or peripheral neuroimmune dysregulation, activation of both extrinsic and intrinsic coagulation pathways, and microbial infections. Besides mast cells, recent reports suggest the active and direct involvement of basophils and eosinophils. Several biological characteristics or biomarkers have been linked with CSU's known endotypes and may help forecast therapeutic responses. The introduction of biologic therapy for CSU has been a major advance in the last 10 years. The cornerstone of angioedema (AE) pathogenesis is increased vascular permeability and plasma leakage into the deeper dermis and subcutis, either mediated by histamine or bradykinin (BK). C1-inhibitor deficiency, hereditary or acquired, is the primary cause of BK-mediated AE due to increased plasma BK concentration. Other complex conditions have been identified, with some likely involving contact system dysregulation and other putative mechanisms related to vascular endothelial dysfunction. The approval of multiple hereditary-AE-specific therapies for both prevention and acute attacks has revolutionized treatment of this disease. Any new knowledge of the pathogenesis of CSU and AE offers the opportunity to improve patient information, physician-patient communication, prediction of therapeutic responses, selection of precise tailor-made treatment for each patient, and exploration of novel treatment options for those who do not achieve disease control with current medications.

Dietary Factors May Delay Tolerance Acquisition in Food Protein-Induced Allergic Proctocolitis.

BACKGROUND: Dietary and environmental factors may influence tolerance acquisition in food protein-induced allergic proctocolitis (FPIAP). This retrospective observational study explored the role of maternal diet during pregnancy and breastfeeding in tolerance acquisition in infantile FPIAP. METHODS: Breastfed infants with FPIAP from six diverse regions in Greece were divided into two groups, based on development of tolerance to the trigger food: Group A (n = 43), before, and Group B (n = 53), after, the 6th month of age. Maternal diet during pregnancy and breastfeeding was elicited using the Mediterranean Diet Score Questionnaire and the Mediterranean Oriented Culture Specific Semi-Quantitative Food Frequency Questionnaire. RESULTS: Mean age at diagnosis of FPIAP (1.5 months) and weaning (5.5 months) were the same in both groups. The main trigger was cow's milk. Group A received infant milk formula earlier than Group B. Group B had a higher incidence of asthma/wheeze, siblings with milk allergy, maternal smoking and rural residence. On multivariate analysis, earlier resolution of FPIAP was associated with higher maternal education and with salt intake and consumption of goat/sheep cheese during pregnancy and olive oil during breastfeeding. Consumption of multivitamins during pregnancy and meat, winter fruits, green vegetables, butter, salt, "ready-to-eat" meals and pastries during breastfeeding were correlated with longer duration of symptoms. CONCLUSIONS: Mothers of children with FPIAP to cow's milk protein can be advised to eat more yogurt, cheese and olive oil during subsequent pregnancies, and avoid multivitamins, grilled food, "ready-to-eat" meals, pastries, meat and alcohol during breastfeeding, to reduce the duration of FPIAP presenting in future infants.

Psychiatric comorbidities in children and adolescents with chronic urticaria.

BACKGROUND: Chronic urticaria (CU) has been shown to impact patients' quality of life negatively and may coexist with psychiatric disorders. We systematically reviewed the published evidence of comorbid psychiatric disorders in children and adolescents with CU. METHODS: A systematic review of studies published until February 2022 in PubMed, Google Scholar, and Scopus was performed. An a priori set of inclusion criteria was predefined for the studies to be included: (1) clear distinction between urticaria and other allergies; (2) precise distinction between acute and CU; (3) participants younger than 18 years old, exclusively; (4) use of appropriate standardized questionnaires, psychometric tools, and standard diagnostic nomenclature for the mental health and behavioral disorders diagnosis; and (5) manuscripts written or published in the English language. RESULTS: Our search identified 582 potentially relevant papers. Only eight of them satisfied the inclusion criteria. Quantitative meta-analysis was not deemed appropriate, given the lack of relevant randomized control trials, the small number of relevant shortlisted, the small sample size of the patients included in each study, and the remarkable heterogeneity of the studies' protocols. CONCLUSIONS: The included studies suggest an increased incidence of psychopathology among children and adolescents with CU as opposed to healthy age-matched individuals, but the data are scarce. Further research is required to clarify whether psychopathology is just a comorbid entity, the cause, or the consequence of CU. Meanwhile an interdisciplinary collaboration between allergists/dermatologists and psychiatrists is expected to substantially minimize CU burden and improve patients' quality of life.

Further Understanding of Neuro-Immune Interactions in Allergy: Implications in Pathophysiology and Role in Disease Progression.

The complicated interaction between the central and the autonomic (sympathetic, parasympathetic, and enteric) nervous systems on the one hand and the immune system and its components, on the other hand, seems to substantially contribute to allergy pathophysiology, uncovering an under-recognized association that could have diagnostic and therapeutic potentials. Neurons connect directly with and regulate the function of many immune cells, including mast cells, the cells that have a leading role in allergic disorders. Proinflammatory mediators such as cytokines, neurotrophins, chemokines, and neuropeptides are released by immune cells, which stimulate sensory neurons. The release of neurotransmitters and neuropeptides caused by the activation of these neurons directly impacts the functional activity of immune cells and vice versa, playing a decisive role in this communication. Successful application of Pavlovian conditioning in allergic disorders supports the existence of a psychoneuroimmunological interplay in classical allergic hypersensitivity reactions. Activation of neuronal homeostatic reflexes, like sneezing in allergic rhinitis, coughing in allergic asthma, and vomiting in food allergy, offers additional evidence of a neuroimmunological interaction that aims to maintain homeostasis. Dysregulation of this interaction may cause overstimulation of the immune system that will produce profound symptoms and exaggerated hemodynamic responses that will lead to severe allergic pathophysiological events, including anaphylaxis. In this article, we have systematically reviewed and discussed the evidence regarding the role of the neuro-immune interactions in common allergic clinical modalities like allergic rhinitis, chronic rhinosinusitis, allergic asthma, food allergy, atopic dermatitis, and urticaria. It is essential to understand unknown - to most of the immunology and allergy experts - neurological networks that not only physiologically cooperate with the immune system to regulate homeostasis but also pathogenetically interact with more or less known immunological pathways, contribute to what is known as neuroimmunological inflammation, and shift homeostasis to instability and disease clinical expression. This understanding will provide recognition of new allergic phenotypes/endotypes and directions to focus on specialized treatments, as the era of personalized patient-centered medicine, is hastening apace.

Delayed pressure urticaria manifesting as dyspareunia - is it that uncommon?

Delayed pressure urticaria (DPU) is a variant of physical urticaria characterised by reproducible whealing on application of sustained pressure to the skin. Clinical manifestations include delayed cutaneous erythema, edema and subcutaneous swelling, typically occurring 4-6h after application of mechanical pressure. Dyspareunia is defined as persistent or recurrent pain in the genital area or within the pelvis that occurs just before, during, or after sexual intercourse. We report an unusual case of DPU manifesting as dyspareunia.

Food Protein-Induced Allergic Proctocolitis: The Effect of Maternal Diet During Pregnancy and Breastfeeding in a Mediterranean Population.

Background: The aim of the current investigation was to explore the association of food protein-induced allergic proctocolitis (FPIAP) with the maternal diet during pregnancy and breastfeeding in Greek infants. Methods: A multicenter retrospective case-control study was conducted in 6 regions in Greece, with 96 mothers of infants with and 141 mothers of infants without a history of FPIAP. Maternal dietary habits during pregnancy and breastfeeding were evaluated with the following validated questionnaires: (a) The Mediterranean Diet Score and (b) The Mediterranean Oriented Culture-Specific Semi-Quantitative Food Frequency Questionnaire. Results: FPIAP was associated with cow's milk (83.6%), egg (7.3%), wheat (6.4%), and beef (6.4%) in the maternal diet. Adherence to Mediterranean Diet was similar among the mothers. Mothers of FPIAP infants consumed more vegetables. Elastic net prediction models showed that, in this Mediterranean population, increased consumption during pregnancy and lactation of common allergens, whole grain products, homemade food, fish and shellfish, and fruits was associated with a decreased risk of FPIAP. Conversely, a high intake of vegetables, sugar and total fat, and non-stick/grilled cooking, were associated with increased risk of FPIAP, as was a high intake of salt and white flour during lactation only. Conclusions: Components of a maternal Mediterranean Diet may protect against FPIAP when traditional cooking methods are adopted and fish, fruit, and whole wheat products are consumed frequently during pregnancy and breastfeeding.

Explaining COVID-19 postvaccination-related immune thrombotic thrombocytopenia: a hypothesis-generating in-silico approach.

Cases that experienced COVID-19 postvaccination-related thrombosis have been reported after the first dose of ChAdOx1 nCov-19 (Vaxzevria, AstraZeneca) or Ad26.COV2.S (Johnson & Johnson/Janssen) vaccine. These rare thrombotic events were observed within the expected vaccine-induced seroconversion period and could be attributed to platelet-activating (auto)antibodies against platelet factor 4 (PF4). Newly, vaccine-induced, cross-reactive anti-PF4 antibodies could explain this observation. An in-silico analysis using the Basic Local Alignment Search Tool was used to identify sequence similarity between PF4 and antigens contained in or encoded by ChAdOx1 nCov-19 or Ad26.COV2.S vaccines. Only one sequence within the signaling peptide of the SARS-CoV-2 spike protein exhibited a high percent identity (85.71%) with PF4. This sequence overlaps with a proven immunogenic peptide recognized from convalescent COVID-19 sera and could be responsible for the formation of platelet-activating immunocomplexes in susceptible patients. Manipulation of the immunogenicity of this particular sequence within the encoded SARS-CoV-2 spike protein signaling peptide may eliminate this iatrogenic severe adverse effect.

A European survey of management approaches in chronic urticaria in children: EAACI pediatric urticaria taskforce.

BACKGROUND: Although well described in adults, there are scarce and heterogeneous data on the diagnosis and management of chronic urticaria (CU) in children (0-18 years) throughout Europe. Our aim was to explore country differences and identify the extent to which the EAACI/GA²LEN/EDF/WAO guideline recommendations for pediatric urticaria are implemented. METHODS: The EAACI Task Force for pediatric CU disseminated an online clinical survey among EAACI pediatric section members. Members were asked to answer 35 multiple choice questions on current practices in their respective centers. RESULTS: The survey was sent to 2,773 physicians of whom 358 (13.8%) responded, mainly pediatric allergists (80%) and pediatricians (49.7%), working in 69 countries. For diagnosis, Southern European countries used significantly more routine tests (eg, autoimmune testing, allergological tests, and parasitic investigation) than Northern European countries. Most respondents (60.3%) used a 2nd -generation antihistamine as first-line treatment of whom 64.8% updosed as a second line. Omalizumab was used as a second-line treatment by 1.7% and third line by 20.7% of respondents. Most clinicians (65%) follow EAACI/WAO/GA2LEN/EDF guidelines when diagnosing CU, and only 7.3% follow no specific guidelines. Some clinicians prefer to follow national guidelines (18.4%, mainly Northern European) or the AAAAI practice parameter (1.7%). CONCLUSIONS: Even though most members of the Pediatric Section of EAACI are familiar with the EAACI/WAO/GA2LEN/EDF guidelines, a significant number do not follow them. Also, the large variation in diagnosis and treatment strengthens the need to re-evaluate, update, and standardize guidelines on the diagnosis and management of CU in children.

Eosinophilic cystitis refractory to steroids successfully treated with benralizumab: A case report.

We report a case of a 66-year-old male diagnosed with refractory to oral corticosteroids eosinophilic cystitis (EoC). Hematuria was the first and only sign of the disease that was otherwise asymptomatic, and the only abnormal lab finding he had was peripheral eosinophilia (700 cells/µl). Due to cardiovascular issues, an invasive surgical procedure was declined. As an alternative, benralizumab, an anti-IL-5Rα monoclonal antibody with anti-eosinophilic properties, was administered. The patient responded rapidly with clinical and histological complete remission of the EoC four months after benralizumab started. He continued benralizumab 30 mg Q4-weeks for 12 months without experiencing any side effects. Six months after the last dose, he is completely healthy with no peripheral eosinophilia. EoC is a rare condition with no standardized treatment. Those with corticosteroid-refractory EoC are eligible for surgery. Benralizumab has an excellent safety profile; therefore, it should be considered before deciding on invasive surgical procedures in selected, refractory to non-specific treatment cases, especially with EoC of unclear etiology. It is unclear if benralizumab may immunomodulate the unknown underlying mechanisms of EoC, considering that EoC did not relapse after benralizumab was deemed eliminated. Further studies are needed to investigate this possibility.