Does the severity of atopic dermatitis change with allergic sensitization? Is it real or a myth?

Objective: Atopic dermatitis (AD) is a chronic inflammatory skin disease that can occur at any age. This study aimed to evaluate the impact of food allergy on disease severity as well as clinical/laboratory findings in children with AD. Methods: Clinical and laboratory data of AD patients evaluated for food allergy between January 2021 and December 2022 were examined retrospectively. Results: Of the 52 patients evaluated, 32 (61.5%) were males, with a median age of 6 months (2–118 months). Among them, 26 (50%) had food allergies (FA) and five (9.6%) had inhalant allergen sensitivity. No significant difference in AD severity was observed between patients with and without FA. However, the FA group showed higher serum lactate dehydrogenase (LDH) levels (343.3 ± 81.5 U/L vs 297.7 ± 77.4 U/L; P = 0.011) and lower red cell distribution width (RDW). Inhalant allergen sensitivity was associated with higher AD severity. Conclusion: While guidelines recommend investigating food allergies in moderate to severe AD, this study found no significant difference in the relationship between AD severity and the presence of FA. However, inhalant allergen sensitivity was linked to increased AD severity. Therefore, a comprehensive patient history should include an evaluation of food allergies in children with AD, regardless of disease severity. Elimination and provocation tests related to suspected food items should be performed, and allergenic foods should be removed from the diet if they are found to contribute to the allergy (AU)

Where's the Beef? Understanding Allergic Responses to Red Meat in Alpha-Gal Syndrome.

Alpha-gal syndrome (AGS) describes a collection of symptoms associated with IgE-mediated hypersensitivity responses to the glycan galactose-alpha-1,3-galactose (alpha-gal). Individuals with AGS develop delayed hypersensitivity reactions, with symptoms occurring >2 h after consuming mammalian ("red") meat and other mammal-derived food products. The mechanisms of pathogenesis driving this paradigm-breaking food allergy are not fully understood. We review the role of tick bites in the development of alpha-gal-specific IgE and highlight innate and adaptive immune cells possibly involved in alpha-gal sensitization. We discuss the impact of alpha-gal glycosylation on digestion and metabolism of alpha-gal glycolipids and glycoproteins, and the implications for basophil and mast cell activation and mediator release that generate allergic symptoms in AGS.

Food Allergy Guidelines for Schools and Childcare Facilities.

Among controversial new recommendations: doing away with categorical food bans.

Allergy to Mammalian Meat Linked to Alpha-Gal Syndrome Potentially After Tick Bite in the Amazon: A Case Series.

The past decade has seen the emergence of a new type of food allergy occurring after ingestion of mammalian meat. This allergy is related to immunoglobulin (Ig)E specific for galactose-alpha-1,3 galactose (α-Gal). Originally described in the United States in 2009, other cases have subsequently been described in Australia and in Europe, but still very few in Latin America. The purpose of this study was to show the existence of this pathology in French Guiana and to describe the historical, clinical, and biological characteristics of these patients. Patients reporting an allergy to mammalian meat were included between September 2017 and August 2019. Eleven patients were included, nine of whom exhibited digestive symptoms; four, urticaria reactions; three, respiratory reactions; and five angioedema. The time between ingestion of red meat and reaction varied between 1.5 and 6 hours. The implicated meats were most often beef and pork. All patients had been regularly exposed to tick bites before the appearance of symptoms. All the samples (n = 7) were positive for anti-α-Gal anti-mammalian meats IgE. All the patients were Caucasian French expatriates. This study confirms the presence of this new entity in French Guiana and is the largest reported in Latin America. Our results do not clearly allow us to state that tick bites are the cause of this allergy, but all patients reported being exposed regularly to these arthropods.

Pathophysiological Roles of Neuro-Immune Interactions between Enteric Neurons and Mucosal Mast Cells in the Gut of Food Allergy Mice.

Recently, the involvement of the nervous system in the pathology of allergic diseases has attracted increasing interest. However, the precise pathophysiological role of enteric neurons in food allergies has not been elucidated. We report the presence of functional high-affinity IgE receptors (FcεRIs) in enteric neurons. FcεRI immunoreactivities were observed in approximately 70% of cholinergic myenteric neurons from choline acetyltransferase-eGFP mice. Furthermore, stimulation by IgE-antigen elevated intracellular Ca2+ concentration in isolated myenteric neurons from normal mice, suggesting that FcεRIs are capable of activating myenteric neurons. Additionally, the morphological investigation revealed that the majority of mucosal mast cells were in close proximity to enteric nerve fibers in the colonic mucosa of food allergy mice. Next, using a newly developed coculture system of isolated myenteric neurons and mucosal-type bone-marrow-derived mast cells (mBMMCs) with a calcium imaging system, we demonstrated that the stimulation of isolated myenteric neurons by veratridine caused the activation of mBMMCs, which was suppressed by the adenosine A3 receptor antagonist MRE 3008F20. Moreover, the expression of the adenosine A3 receptor gene was detected in mBMMCs. Therefore, in conclusion, it is suggested that, through interaction with mucosal mast cells, IgE-antigen-activated myenteric neurons play a pathological role in further exacerbating the pathology of food allergy.

Cross-sectional imaging of intestinal barrier dysfunction by confocal laser endomicroscopy can identify patients with food allergy in vivo with high sensitivity.

Food allergy (FA) affects approximately 3 to 4% of the adult population in westernized countries. Suspected FA is even more prevalent and requires extensive diagnostic work-up. Within this study, we evaluated whether assessment of the integrity of the epithelial barrier by confocal laser endomicroscopy (CLE) during colonoscopy can be used as a screening tool to identify patients with FA. 60 patients with suspected FA were prospectively included. Serology with total and food-specific IgE, anti-tissue transglutaminase, skin prick testing, food intolerance tests, food intake registration and assessment of clinical complaints were performed. During colonocopy, standardized CLE was performed in the terminal ileum and at two colorectal sites. Analysis of CLE images included functional (i.e. presence of epithelial barrier dysfunction) and quantitative parameters of intestinal architecture. 27 of 60 patients (45%) were diagnosed with FA. Barrier dysfunction was analyzed on 65.837 ileal and on 93.251 colonic images. 96% of patients with FA exhibited functional and structural barrier defects while barrier dysfunction was found in only 33% of patients without FA (p < 0.0001). Visualizing barrier dysfunction with CLE for in vivo diagnosis of FA had a sensitivity and specificity of 96% and 67%, respectively, with a positive and negative prediction of 70% and 96%, respectively. Parameters intrinsic to the crypt architecture including crypt diameter, intercrypt distance, crypt lumen diameter and colonic vasculature were not different between patients with and without FA. CLE-based imaging of the intestinal barrier during colonoscopy might help in stratifying patients with suspected FA for further diagnostic work-up.

Food Allergy and Intolerance: A Narrative Review on Nutritional Concerns.

Adverse food reactions include immune-mediated food allergies and non-immune-mediated intolerances. However, this distinction and the involvement of different pathogenetic mechanisms are often confused. Furthermore, there is a discrepancy between the perceived vs. actual prevalence of immune-mediated food allergies and non-immune reactions to food that are extremely common. The risk of an inappropriate approach to their correct identification can lead to inappropriate diets with severe nutritional deficiencies. This narrative review provides an outline of the pathophysiologic and clinical features of immune and non-immune adverse reactions to food-along with general diagnostic and therapeutic strategies. Special emphasis is placed on specific nutritional concerns for each of these conditions from the combined point of view of gastroenterology and immunology, in an attempt to offer a useful tool to practicing physicians in discriminating these diverging disease entities and planning their correct management. We conclude that a correct diagnostic approach and dietary control of both immune- and non-immune-mediated food-induced diseases might minimize the nutritional gaps in these patients, thus helping to improve their quality of life and reduce the economic costs of their management.

Potential beneficial effects of kefir and its postbiotic, kefiran, on child food allergy.

Food allergies are known as the public health problem, affecting people of all age groups, but more commonly in babies and children, with consequences for nutritional status and quality of life. The increase in the consumption of healthy foods has consequently led to an increased demand for functional foods with specific health benefits. Thus, the pharmaceutical industry's interest in natural products has grown every time and is therefore considered as an alternative to synthetic drugs. Kefir has been outstanding for several years as promising in the manufacture of various pharmaceutical products, due to its nutritional and therapeutic properties for the treatment of many diseases. Currently, a wide variety of new functional foods are appearing on the market, representing an important segment. Postbiotics, for example, has stood out for being a product with action similar to probiotics, without offering side effects. The kefiran is the postbiotic from kefir that promotes potential beneficial effects on food allergy from the intestinal microbiome to the immune system. In this context, it is necessary to know the main promoting component of this functional effect. This review compiles the benefits that kefir, and especially its postbiotic, kefiran, can bring to food allergy. In addition, it serve as a subsidy for studies on the development of innovative nutraceutical products, including the use of kefiran as an alternative therapy in food allergy.

Histamine Intolerance in Children: A Narrative Review.

Histamine intolerance is defined as a disequilibrium of accumulated histamine and the capacity for histamine degradation. This clinical term addresses a non-immunologically mediated pathology when histamine ingested with food is not particularly high, however its degradation is decreased. This paper aims to provide a narrative review on etiopathology, epidemiology, possible diagnostic algorithms and diagnostic challenges of histamine intolerance in children. The clinical picture of histamine intolerance in children is similar to that observed in adults apart from male predominance found in paediatric patients. Both in children and adults, a histamine-reduced diet is typically the treatment of choice. Diamine oxidase supplementation offers another treatment option. There is no symptom or test pathognomonic for histamine intolerance. Nevertheless, manifestations of chronic gastrointestinal symptoms, measurements of diamine oxidase deficits, positive results of histamine provocation tests and improvement in symptoms with histamine-reduced diet considerably increase the probability of histamine intolerance diagnosis. These factors have been included in the proposed diagnostic algorithm for histamine intolerance. In children histamine intolerance most likely co-occurs with allergies and bowel diseases, which creates an additional diagnostic challenge. As the evidence for children is poor further research is needed the determine epidemiology, validate diagnostic algorithms and establish possible treatment options regarding histamine intolerance.

Atopic dermatitis: More than just a rash.

Atopic dermatitis' association with allergic rhinitis and asthma is well known, but there is also increased risk of food allergies, ADHD, depression, and anxiety.

'Diagnosing food protein-induced enterocolitis syndrome'.

Food protein-induced enterocolitis syndrome is still a mysterious disease, pathogenically poorly characterized, although the first FPIES case has been described in 1967. Mainly, food protein-induced enterocolitis syndrome diagnosis is based on clinical history. The oral food challenge remains the gold standard to confirm the diagnosis, especially in particular situations. Although there are no diagnostic laboratory or imaging tests which are specific for diagnosis, they could, however, sometimes be helpful to rule out clinical conditions which are similar to food protein-induced enterocolitis syndrome reactions. The purpose of this review is to define the clinical features of FPIES and to summarize the current available tools for the diagnosis of FPIES. This review is intended to be a practical guide for the clinician facing a patient with food protein-induced enterocolitis syndrome avoiding delayed diagnosis with unnecessary laboratory tests and detrimental treatments. Moreover, it highlights the unmet needs in diagnosis that require urgent attention from the scientific community to improve the management of patients with FPIES.

Interdisciplinary Significance of Food-Related Adverse Reactions in Adulthood.

Background: Adults frequently interpret food-associated adverse reactions as indicators of a food allergy. However, the public perception of food allergy may differ from a clinician's point of view. The prevalence of patient-reported food allergy tends to be higher than physician-confirmed cases. Dermatological manifestations (urticaria, pruritus, dermatitis, and edema) are frequently reported by patients. Objective: The aim of this study was to describe patient-reported symptoms related to suspected food allergies and particularly to characterize and highlight the volume of patients who visit Budapest allergy clinics with suspected food allergies. Methods: In this prospective study, adult (≥18 years) patients were examined at the Allergology Outpatient Unit of the Dept. of Dermatology, Venereology, and Dermatooncology, Semmelweis University, Budapest. The examination included a detailed medical history; physical examination; and when necessary the measurement of allergen-specific serum immunoglobulin E (IgE) levels. Results: Data from 501 patients (393 women, 108 men) were analyzed. Intolerance to dietary biogenic amines occurred in 250 cases (250/501, 50%). Oral allergy syndrome was confirmed in 71 patients (71/501, 14%). Allergy to food preservatives was diagnosed in 14 (14/501, 3%) cases by a dermatologist-allergist specialist. Five individuals (5/501, 1%) were diagnosed with IgE-mediated food allergy. In some cases (28/501, 6%), edema-inducing/enhancing side effects of drugs were observed which patients had misattributed to various foods. Among the food groups considered to be provoking factors, the most frequently mentioned were fruits (198/501, 40%), milk/dairy products (174/501, 35%), and nuts/oilseeds (144/501, 29%). Overwhelmingly, urticaria (47%) was the most common dermatological diagnosis, followed by dermatitis (20%) and allergic contact dermatitis (8%). Conclusion: Improvement is needed in food allergy, food intolerance, and general nutritional knowledge among the general public. According to our data, perceived/self-reported food allergies were overestimated by adults when compared against physician-confirmed food allergies; however, other diseases potentially responsible for food-related problems were underestimated. The prevalence of oral allergy syndrome was high in the cohort. Intolerance to dietary biogenic amines was common, and although the role of dietary histamine and biogenic amine is not entirely understood in eliciting patients' symptoms, improvements in complaints were reported during the control visits.

Phenotypes and natural history of food protein-induced enterocolitis syndrome in the east Mediterranean region.

Background: Food protein-induced enterocolitis syndrome (FPIES) is a rare non-IgE mediated food allergy. Objective: To delineate the differences in the spectrum of culprit foods, remission patterns, and predictors among varying cultures. Methods: We reviewed demographics, culprit foods, outcomes, and predictors in 81 children with a diagnosis of FPIES who were followed up between 2015 and 2020. Results: Eighty-one patients (55.6% boys) were enrolled, including 72 with acute FPIES and 9 with chronic FPIES. Hen's egg was the most common culprit food (36.6%), followed by fish (26.9%), and cow's milk (21.5%). Interestingly, cow's milk was significantly prevalent in chronic FPIES cases (p = 0.006). The most common clinical symptoms were vomiting (100%), pallor (63.4%), and lethargy (55.9%). Emergency department visits were noted in 39 patients (41.9%), of whom 37 (39.8%) were treated with intravenous (IV) fluid. The subjects were followed up for a median (interquartile range) of 19.4 months (12.3-41.2 months), and 26 subjects (32.1%) achieved tolerance. The median (interquartile range) age at tolerance was 2.5 years (2.1-3.2 years). With regard to the culprit foods, hen's egg was observed more frequently in the subjects with resolved FPIES cases (p = 0.008), whereas fish FPIES cases were high in the persistent group (p = 0.001). IgE sensitization of the culprit food was found to be an independent risk factor for the persistence of FPIES (odds ratio 4.855 [95% confidence interval, 1.131-20.844]; p = 0.034). Conclusion: In our cohort, unlike other published series, hen's egg and fish were the two most common culprit foods. Fish differed from other culprit foods, with significantly delayed onset and persistence, and may create a model that allows for the understanding of the disease.

Protective Effect of Glycomacropeptide on Food Allergy with Gastrointestinal Manifestations in a Rat Model through Down-Regulation of Type 2 Immune Response.

Glycomacropeptide (GMP) is a bioactive peptide derived from milk κ-casein with immune-modulatory and anti-inflammatory properties. Food allergy (FA) is an adverse immune reaction with a broad spectrum of manifestations. Allergen intake induces persistent intestinal inflammation and tissue damage. In this study, the anti-allergic activity of GMP was evaluated using a rat ovalbumin (OVA)-induced FA model with gastrointestinal manifestation. Rats were orally GMP treated from 3 days prior and during FA development. The severity of food anaphylaxis and diarrheal episodes, antibody production and histamine level were measured. Histopathological changes, inflammation and predominant cytokine profile at intestine were analyzed. Oral GMP intake decreased clinical signs and diarrhea severity induced by allergen, with a significant reduction in intestinal edema and expression level of IL-1ß and TNF-α. Prophylaxis with GMP also diminished serum anti-OVA IgE and IgG1, and histamine levels. GMP treatment markedly decreased eosinophil infiltration, mast cell and goblet cell hyperplasia, total IgE expression in intestine, and prevented histological changes in villi, crypts and internal muscularis layer. The treatment effectively suppressed IL-5, IL-13 and GATA3 expression and skewed the intestinal cytokine profile toward type 1 and regulatory. These results suggest that GMP may protect against FA through down-regulating the type 2 inflammatory response.

Production of allergen-specific immunotherapeutic agents for the treatment of food allergy.

Allergen-specific immunotherapy (IT) is emerging as a viable avenue for the treatment of food allergies. Clinical trials currently investigate raw or slightly processed foods as therapeutic agents, as trials using food-grade agents can be performed without the strict regulations to which conventional drugs are subjected. However, this limits the ability of standardization and may affect clinical trial outcomes and reproducibility. Herein, we provide an overview of methods used in the production of immunotherapeutic agents for the treatment of food allergies, including processed foods, allergen extracts, recombinant allergens, and synthetic peptides, as well as the physical and chemical processes for the reduction of protein allergenicity. Commercial interests currently favor producing standardized drug-grade allergen extracts for therapeutic use, and clinical trials are ongoing. In the near future, recombinant production could replace purification strategies since it allows the manufacturing of pure, native allergens or sequence-modified allergens with reduced allergenicity. A recurring issue within this field is the inadequate reporting of production procedures, quality control, product physicochemical characteristics, allergenicity, and immunological properties. This information is of vital importance in assessing therapeutic standardization and clinical safety profile, which are central parameters for the development of future therapeutic agents.

Physiopathology of food allergies.

Food allergy is adverse reaction to certain foods and it arise from a specific immune response, including reactions mediated by immunoglobulin (Ig) E, by cells, or by both. Although individuals of all ages can develop it, the pediatric population is the most affected by it; with a prevalence of 6 to 8 %. In homeostatic conditions, the organism has tolerance and regulation pathways that hinder food components from causing damage or adverse immune reactions. However, under specific conditions such as genetic predisposition, environmental factors, dietary patterns, or premature exposure to certain foods, tolerance is not developed and aberrant and excessive immune responses to food antigens happen. Understanding the complex physiopathological mechanisms that are present during the establishment and evolution of food allergies allows the identification of potential therapeutic targets and the development of more effective therapies aimed to modify the natural course of the allergy and to improve the patients' quality of life. The objective of this review is to give an updated vision of the existing knowledge about predisposition, sensitization pathways, manifestations, and therapies in IgE-mediated food allergies, delving into the molecular and cellular mechanisms of its physiopathology.

La alergia alimentaria es una reacción adversa hacia determinados alimentos, que surge de una respuesta inmune específica, incluyendo reacciones mediadas por inmunoglobulinas (Ig) E, por células o por ambos. Aunque puede desarrollarse en individuos de todas las edades, la población infantil es la más afectada, con una prevalencia de 6 a 8 %. En condiciones de homeostasis, en el organismo existen vías de regulación y de tolerancia que impiden que los componentes de los alimentos originen daño o despierten reacciones inmunológicas adversas. Sin embargo, en condiciones específicas como carga genética predisponente, factores ambientales, patrones dietarios o exposición prematura a ciertos alimentos, no se desarrolla tolerancia y acontecen respuestas inmunológicas excesivas y aberrantes a antígenos alimentarios. La comprensión de los complejos mecanismos fisiopatológicos presentes durante el establecimiento y evolución de la alergia alimentaria permite identificar blancos terapéuticos potenciales y desarrollar terapias más efectivas dirigidas a modificar el curso natural de la alergia y mejorar la calidad de vida de los pacientes. La presente revisión pretende dar una visión actualizada del conocimiento existente sobre la predisposición, vías de sensibilización, manifestaciones y tratamientos de las alergias alimentarias mediadas por IgE, profundizando en los mecanismos moleculares y celulares de su fisiopatología.