Food Allergy Syndrome Research Articles

An International Delphi Consensus on the Management of Pollen–Food-Allergy Syndrome: A Work Group Report of the AAAAI Adverse Reactions to Foods Committee

Pollen-food-allergy syndrome (PFAS) is common among patients with allergic rhinitis. Treatment recommendations for patients with PFAS remain variable. To develop consensus recommendation statements for managing patients with PFAS. An international panel of allergists, researchers, and nutritionists with an interest in PFAS from 25 different institutions across 11 countries convened and a list of statements was written by 3 authors. The RAND/University of California Los Angeles methodology was adopted to establish consensus on the statements. After 2 Delphi rounds, a consensus was reached on 14 statements. The panel agreed that patients with PFAS would benefit from counseling on the nature and basis of PFAS and the rare chance of more severe systemic reactions and their recognition. The panel agreed on avoiding the raw food responsible for the index reaction, but not potentially cross-reactive fruits/vegetables based on the responsible food of the index reaction. Epinephrine autoinjectors should be recommended for patients with PFAS who experienced severe symptoms (beyond the oropharynx) or for patients considered at risk for severe reactions. The panel agreed that the benefit of allergen immunotherapy remains unclear and that PFAS should not be considered the primary indication for such intervention. We developed consensus statements regarding counselling patients about the nature and severity of PFAS, potential risk factors, dietary avoidance, epinephrine autoinjector prescription, and allergen immunotherapy consideration for patients with PFAS.

Neglected but Clinically Relevant Allergens in Korea.

Allergy diagnostics and immunotherapeutics in Asia heavily rely on imported products from Western countries, raising concerns about the accuracy and efficacy of these products for the management of Asian allergy patients. Recent advancements in allergen research have led to the identification and characterization of novel allergens from indigenous Korean species. While some allergens share homology with well-known allergens, others lack counterparts in imported allergen extracts. Classifying regional allergens in Asia into three categories based on their cross-reactivity with imported allergens offers valuable insights. Highly cross-reactive allergens, such as oak allergens Que m 1 from Quercus mongolica and Que ac 1 from Q. acutissima, can be effectively substituted with the imported allergens. Allergens with partial cross-reactivity, like the Asian needle ant allergen Pac c 3 (Antigen 5), permit limited diagnostic value by the currently available products. Unique allergens, including the Japanese hop allergen Hum j 6 (pectin methylesterase inhibitor) and the silkworm pupa allergen Bomb m 4 (30kDa hemolymph lipoprotein) lack alternatives in the available product list. Greater attention is needed, particularly for species listed as ecologically invasive in Western regions. Additionally, allergens from domestic fruits and vegetables causing pollen food allergy syndrome require characterization for the development of improved diagnostics.

Identifying thresholds of reaction for different foods.

Current food allergy management universally treats all patients with food allergy as being at risk for anaphylaxis (with the exception perhaps of pollen food allergy syndrome). Thus, patients are told to avoid the allergenic food in all potentially allergic forms and amounts. However, research over the past 2 decades has shown that many patients will tolerate small amounts of the allergen without any allergic reaction. Thus, if one were able to identify the threshold of reactivity, this could change management. At the population level, establishing levels at which the vast majority of patients (e.g., 95%) do not react could have public health ramifications, such as altering labeling laws. At the individual patient level, personal threshold levels could determine avoidance strategies, affect quality of life, and alter treatment decisions, e.g., oral immunotherapy starting doses. In this review, threshold data for various allergens and their potential effect on the management of the patient with food allergy are examined.

Pollen food allergy syndrome secondary to molds and raw mushroom cross-reactivity: a case report

BackgroundPollen food allergy syndrome (PFAS) is an immunoglobulin E (IgE) mediated reaction that causes oropharyngeal pruritus or angioedema due to homologous proteins present in the culprit food as well as a sensitizing aeroallergen. This cross-reactivity has been well established between pollen and fruits/vegetables. Given the evolutionary similarity between all fungi; cross-reactivity between spore forming microfungi and edible macrofungi have been suggested, however only a limited number of case reports have ever been published on this phenomenon. We present a case of a patient who experiences pollen food allergy syndrome-like symptoms following lightly cooked mushroom ingestion who otherwise was able to tolerate cooked mushrooms. We then review the literature to highlight the limited studies of an underrecognized PFAS cross-reactivity between molds and mushrooms.Case presentationA 15-year-old male presents with symptoms of seasonal and perennial allergic rhinitis was found to have multiple environmental sensitizations to molds via skin prick testing (C.gramineum, A.Pullulans and B.cinerea) and ImmunoCAP serum-specific IgE (A.alternata, C. herbarum, and P. notatum). He developed throat pruritus and subjective throat tightness following ingestion of mushroom containing pizza. ImmunoCAP serum specific IgE to whole mushroom was negative but fresh food prick testing to fresh portobello mushroom and cremini mushroom were both positive with a negative test to canned mushroom. The patient then underwent a graded oral challenge and successfully tolerated canned mushrooms.ConclusionThis case highlights the potential cross-reactivity between microfungi aeroallergens and edible fungi, leading to PFAS-like reactions in susceptible individuals. The patient’s ability to tolerate canned mushrooms suggests a possible heat-labile protein as the cause of the reaction, similar to PFAS patients tolerating cooked but not raw fruits/vegetables. Positive skin prick test to both spore-forming fungi and edible fungi with negative and whole mushroom IgE results further support the hypothesis of cross-reactivity and sensitization. Further research is needed to identify the specific allergenic proteins involved in these cross-reactions and the susceptible species of mold and mushroom. Understanding these components will contribute to improved diagnosis and management of mold and mushroom allergies, and enhance our knowledge of allergenic cross-reactivity in general.

Occurrences of allergenicity to banana pathogenesis-related-10 (PR10) protein variants.

Pathogenesis-related-10 (PR10) proteins play significant roles in plant defence against biotic and abiotic stresses. Recently, two banana PR10 proteins (MaPR10-BeB5 and MaPR10-GNA5) were characterised and shown to exhibit antifungal properties against Aspergillus fumigatus in vitro. In rice, transgenic overexpression of PR10 proteins conferred resistance to pathogen infection and drought tolerance without affecting productivity, highlighting their potential for agricultural applications. However, PR10 proteins also include the Bet v 1-like family of allergens implicated in pollen food allergy syndromes, raising concerns about potential adverse effects on human health. In this study, we evaluated the allergenic potential of the recently isolated banana PR10 proteins. We first predicted the presence of IgE epitopes of the Bet v 1 allergen family in the deduced PR10 peptide sequences in silico. We then predicted the structures of four human IgE scFv protein sequences and three plant PR10 protein sequences. Based on the quality of the predicted structures, one IgE scFv protein structure was selected for docking with the three plant PR10 proteins. We confirmed the docking results with immunoblot analysis performed using recombinant MaPR10-BeB5 and MaPR10-GNA5 proteins against the sera of banana-allergic patients. Our experimental results substantiated the notion that both protein variants are potentially allergenic since these proteins were recognised by 26.6% of banana-allergic patients with broad PR10 protein recognition. We caution that the allergenic potential of MaPR10 proteins should be carefully considered before implementing transgenic overexpression strategies to improve crops, with a suggestion to limit their expression to non-edible plant tissues.

Revisiting Fruit Allergy: Prevalence across the Globe, Diagnosis, and Current Management.

Fruit allergies manifest with a diverse array of clinical presentations, ranging from localized contact allergies and oral allergy syndrome to the potential for severe systemic reactions including anaphylaxis. The scope of population-level prevalence studies remains limited, largely derived from single-center or hospital-based investigations. In this comprehensive review, we conducted a systematic literature search spanning the years 2009 to 2023, with full acknowledgment of potential analytical biases, to provide a global overview of fruit allergy prevalence. The primary mechanistic underpinning of fruit allergies stems from cross-reactivity between aeroallergens and food allergens, a consequence of structurally similar epitopes-a phenomenon recognized as pollen food allergy syndrome (PFAS). In the era of molecular allergology, numerous studies have dissected allergen components with substantial clinical relevance. Within this review, we explore important allergenic molecules found in plant-based foods, scrutinize pertinent cross-reactivity patterns, and offer insights into management recommendations. Additionally, we compare guideline recommendations to enhance clinical understanding and inform decision making.

2023 AAHA Management of Allergic Skin Diseases in Dogs and Cats Guidelines.

These guidelines present a systematic approach to diagnosis, treatment, and management of allergic skin diseases in dogs and cats. The guidelines describe detailed diagnosis and treatment plans for flea allergy, food allergy, and atopy in dogs and for flea allergy, food allergy, and feline atopic skin syndrome in cats. Management of the allergic patient entails a multimodal approach with frequent and ongoing communication with the client. Obtaining a comprehensive history is crucial for diagnosis and treatment of allergic skin diseases, and the guidelines describe key questions to ask when presented with allergic canine and feline patients. Once a detailed history is obtained, a physical examination should be performed, a minimum dermatologic database collected, and treatment for secondary infection, ectoparasites, and pruritus (where indicated) initiated. The process of diagnosing and managing allergic skin disease can be prolonged and frustrating for clients. The guidelines offer recommendations and tips for client communication and when referral to a dermatologist should be considered, to improve client satisfaction and optimize patient outcomes.

Profiles of Birch Allergen Component Sensitization and Its Association with Pollen Food Allergy Syndrome in Northern China.

To investigate the major allergen components associated with birch pollen allergy in northern China and elucidate clinical relevance to pollen food allergy syndrome (PFAS). Fifty-eight patients were recruited for a cross-sectional study and categorized into two groups: PFAS group and non-PFAS group, as well as apple allergy group and non-apple allergy group. The sIgE levels of birch pollen and its components, namely Bet v 1, Bet v 2, Bet v 4, and Bet v 6, were analyzed. Among 58 participants, 44 individuals (75.9%) reported PFAS. 32 out of 44 (72.7%) participants reported apple allergy. Bet v 1 exhibited the highest sensitization rate at 82.8%, followed by Bet v 2 (29.3%) and Bet v 6 (1.7%). The combined sensitization rate for Bet v 1 and/or Bet v 2 was 93.1%. A total of 77.6% of the subjects demonstrated sensitization to single component, while 19.0% exhibited sensitization to two components. The sIgE levels of birch pollen and Bet v 1 were significantly elevated in PFAS group compared to non-PFAS group (p=0.001, p<0.001, respectively), as well as in apple-allergic and non-apple-allergic group (p<0.001, p<0.001, respectively). The optimal cut-off values for birch pollen and Bet v 1 sIgE were determined to be 7.09 kUA/L (with a sensitivity of 84.1% and specificity of 78.6%) and 5.11 kUA/L (with a sensitivity of 75.0% and specificity of 85.7%) when diagnosing PFAS. In terms of apple allergy, the optimal cut-off value were 9.40 kUA/L (with a sensitivity of 81.3% and specificity of 76.9%) and 6.53 kUA/L (with a sensitivity of 84.4% and specificity of 84.6%), respectively. The predominant sensitization pattern is mono-sensitization to Bet v 1, but when considering immunotherapy, Bet v 2 should also be taken into account. Bet v 1 serves as a valuable biomarker for diagnosing PFAS and apple allergy.

Optimization of the diagnosis and characterization of gibberellin-regulated protein sensitization: An Italian cohort study

BackgroundPru p 7 was the first gibberellin-regulated protein (GRP) to be identified as a food allergen as the basis of a pollen food allergy syndrome. ObjectiveTo clinically and biologically characterize a group of patients with suspected allergy to Pru p 7 to optimize the diagnostic workup of GRP sensitization. MethodsAllergy to Pru p 7 was suspected in the presence of a systemic allergic reaction to plant food, positive skin prick test results for cypress pollen and lipid-transfer protein–enriched peach extract, and absence of Pru p 3-specific immunoglobulin E. Controls were patients with food allergies, patients sensitized to Pru p 3, and patients with cypress allergy without food allergy. Diagnostic workup included skin tests, basophil activation test, Western blot, and single and multiplex assays. ResultsIn total, 23 patients and 14 controls were enrolled. The most implicated food was peach (91.3%). Approximately 70% of patients reacted to multiple foods. Mueller 4 reactions were 8.7%. In 26.1% of cases, a cofactor triggered the reaction. The basophil activation test results were positive for rPru p 7 in 87% of the patients. Specific immunoglobulin E to Pru p 7 was detected in 95.7% by singleplex and in 73.9% by multiplex assays in patients with suspected allergies; 73.9% of them also reacted to cypress pollen GRP (Cup s 7) in Western blot analysis. ConclusionPatients with Pru p 7-Cup s 7 allergy in our cohort confirm a mild-to-severe clinical syndrome characterized by pollen and food allergy. The diagnosis may benefit from the proposed selection criteria that can be used as preliminary steps to further characterize the cross-reactive GRP sensitization.

Research progress on pollen food allergy syndrome

Pollen food allergy syndrome (PFAS) is an IgE-mediated allergic reaction that occurs when some pollinosis patients ingest certain plant-derived food that contains cross-reactive allergenic components. PFAS is prevalent in both children and adult pollinosis patients. In most cases, PFAS symptoms are confined to the oropharynx and occur within several minutes after oral contact with food. Therefore, PFAS has been also referred as oral allergy syndrome (OAS). A small proportion of PFAS patients would experience systemic symptoms or anaphylaxis. Currently, the diagnosis of PFAS is mainly based on clinical history and allergic tests [skin prick tests and(or) serum specific IgE tests]. Oral provocation tests are used to verify atypical patients. Component-resolved diagnosis is essential for further precise diagnosis and treatment. Management options for PFAS include lifestyle adjustment, symptomatic medication, and immunotherapy. The efficacy and appropriate population for immunotherapy need further investigation. This article aims to update the knowledge on epidemiology, pathogenesis and clinical management of PFAS, thereby enhancing clinicians' understanding as well as treatment progress of this disease entity.

The Role of Peamaclein (Pru p 7) in PFAS Patients: An Italian Real-Life Study

Pollen food allergy syndrome (PFAS) is an allergic reaction to specific foods in persons previously sensitised to pollen. The diagnosis of PFAS is made after taking a patient’s medical history and, in some cases, conducting skin tests and oral food tests with raw fruit or vegetables. The aim of the present study was to evaluate the role of Pru p 7 in patients suspected of having PFAS, who show clinical symptoms, positivity for Cup a 1 and negativity for Pru p 1 and Pru p 3. A total of 51 patients (mean age ± standard deviation, 33 ± 15 years; 20 men and 31 women), referred to the respiratory diseases and allergology units of Siena University Hospital, were enrolled retrospectively. All of them underwent allergy consultation and IgE evaluation for Cup a 1, Pru p 1 and Pru p 3 by immuno solid-phase allergen chip (ISAC). Pru p 7 assay was performed by the ImmunoCAP Phadia method in patients who tested positive for Cup a 1 and simultaneously negative for Pru p 1 and Pru p 3 by ISAC. The serum of 51 patients was tested for sensitisation to Pru p 7 by the ImmunoCAP Phadia method, and nine patients (17.65%) were found positive. An area under the receiver operating characteristic (AUROC) curve of 99.51% made it possible to distinguish PFAS and non-PFAS patients on the basis of Pru p 7 values. The best cut-off value was 0.16 kUA/l, which gave a 85.7% sensitivity and 97.73% specificity. This study helps define the role of Pru p 7 in PFAS patients sensitised to cypress pollen and testing negative to Pru p 1 and Pru p 3. A fast, easy and non-invasive diagnostic method is proposed to detect IgE specific for Pru p 7. Inclusion of Pru p 7 in the ISAC assay panel would facilitate the diagnosis of PFAS.

Pollen Food Allergy Syndrome in Japanese Children and Adolescents: Risk Factors and Pollen Sensitisation.

Pollen food allergy syndrome (PFAS) is caused by cross-reactivity with pollen; however, not all-pollen-sensitised individuals develop PFAS, and studies on the characteristics of PFAS development are limited in Japan. We investigated the prevalence and risk factors for the development of PFAS in Japanese children and adolescents sensitised to pollen and their association with pollen-specific IgE levels. The characteristics of PFAS were investigated in patients with allergies aged 3-18 years who visited Dokkyo Medical University Hospital between January 2016 and December 2019. Specific IgE levels for alder, Japanese cedar, ragweed, and orchard grass were measured in patients sensitised to any of the pollens. Patients were categorised into preschool (G1), elementary school (G2), and middle-high school (G3) groups. Overall, 600 patients were enrolled. The prevalence of PFAS was 8.5% in G1, 20% in G2, and 36.3% in G3. Multivariate logistic regression analysis demonstrated strong associations between the risk of developing PFAS and older age (odds ratio (OR), 1.12; 95% confidence interval (CI), 1.06-1.19; P < 0.001), seasonal allergy rhinitis (OR, 6.93; 95% CI, 1.59-30.34; P = 0.010), and alder sensitisation (OR, 6.20; 95% CI, 2.66-14.49; P < 0.001). Spearman's correlation revealed statistically significant positive correlation between each pollen-specific IgE level; high pollen-specific IgE levels were also a risk factor. The OR for being sensitised to all four species was 36.83 (95% CI, 8.93-151.83, P < 0.001) when compared with Japanese cedar alone. Alder was most relevant, with an alder-specific IgE level cutoff value of 2.54 UA/mL. The sensitivity was 78.9%, and the specificity was 70.9%. In conclusion, preschool children develop PFAS with alder sensitisation, and higher pollen-specific IgE levels and increased number of pollen sensitisations are risk factors for developing PFAS.

Food allergy

Food allergy is one of the adverse food reactions, which is developed by immunological reactions. Food allergy is increasing in prevalence among children and adults. In the diagnosis, food challenge is confirmative with history and laboratory tests. Avoidance of culprit food is the only preventive method, especially in patients with severe symptoms. In some food allergies, crossreactivity among allergens should be considered. Latex-fruit/vegetable syndrome and pollen food allergy syndrome are well-understood phenotypes of food allergy related to cross reaction. Red meat allergy is recently described as one of tick-borne diseases. In a rare phenotype of food-dependent exercise-induced anaphylaxis, factors affecting the absorption of food allergen are important in its pathophysiology.

Higher Risk for Sensitization to Commonly Consumed Herbs among Adults and Youngsters Suffering from Birch, Mugwort or Grass Pollinosis.

Background: According to recent findings, mugwort and birch pollen-allergic patients represent a high-risk group for developing adverse allergic reactions to herbal spices due to cross-reacting allergens found in both pollen and raw herbs. Such associations are known as a pollen-plant food allergy syndrome. Objective: The aim of the study was to evaluate the extent of sensitization to commonly consumed herb species representing Lamiaceae, Apiaceae and Brassicaceae families in Polish patients with suspected birch, mugwort or grass pollen allergy. Materials and Methods: Data were obtained from 180 patients, adults and children with suspected allergy to aeroallergens. Skin prick tests (SPT) were performed with standard birch, mugwort, grass mixture or dust mite extracts. Prick by prick tests were performed with fresh extracts of popular herbs: basil, oregano, lemon balm, mint, salvia, rosemary, thyme, anise, caraway and mustard. Results: Twenty-nine percent of patients were characterized by concomitant positive skin prick reactions to both herbs and pollens extracts. The concomitant pollinosis significantly increased the risk of SPT reaction to all tested herbs in adults (odds ratio, OR = 2.15−7.35) and children (OR = 5.3−28). The extent of SPT responses to herbs from Lamiaceae + Apiaceae were strongly correlated with SPT responses to pollens in the pediatric group (r = 0.685/p < 0.001). Conclusion: The study demonstrates that youngsters suffering from pollinosis are at high risk of developing allergic reactions to herbs and highlights the importance of including native skin prick tests with herbs in the diagnostic work-up for suspected food allergy.

ATYPICAL FOOD PROTEIN-INDUCED ENTEROCOLITIS SYNDROME (FPIES) TO SHELLFISH IN A PEDIATRIC PATIENT

<h3>Introduction</h3> Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE mediated food allergy syndrome. Ingestion of food protein causes delayed onset of repetitive projectile vomiting, pallor, diarrhea, lethargy 1-4 hours after intake. Diagnosis is clinical. Pathophysiology involves antigen presentation and TNFα alteration of the intestinal tight junction barrier resulting in fluid shifts and symptoms. Atypical FPIES is rare and includes concomitant IgE sensitization to the food trigger, potentially from ‘Th2-skewing'. The majority of FPIES to seafood are published for adolescents/adults. Our case describes a rare presentation of atypical FPIES to shrimp in infancy. <h3>Case Description</h3> Patient is an 8-year-old male with PMH eczema who presented for evaluation. As a 12-month-old, the patient developed 3 episodes of projectile vomiting and mild lethargy 3 hours after shrimp ingestion. No associated IgE-mediated symptoms. He went to the urgent care and improved with zofran. Family history included atopic conditions of allergic rhinitis and eczema. Testing demonstrated positive skin prick testing (SPT) to shrimp (3 mm wheal) and positive shrimp-IgE (1.49 kU/L). Most recently, he had a repeat reaction to shellfish at age 8 with 4 episodes of vomiting and paleness 2-3 hours after ingestion. <h3>Discussion</h3> Up to 20% of FPIES cases may transform over time to an IgE-mediated phenotype. These atypical FPIES cases have been shown to have longer persistence, as seen in our patient (average tolerance to solid food triggers is age 4). Epinephrine should be prescribed in atypical FPIES due to the risk of anaphylaxis. Treatment includes food avoidance. Further work is essential to determine a disease biomarker.

Oak Pollen Allergy in Korea.

Oak pollen allergy is common all over the world and an important cause of pollinosis. The molecular properties of some component allergens have been clearly characterized, while some of them are still waiting for characterization. Studies on some oak component allergens are neglected, possibly because of its high cross-reactivity to birch. However, the utilization of culprit allergen molecules is expected to increase the diagnostic sensitivity and efficacy of immunotherapy. Sensitization to oak pollen along with birch often causes pollen food allergy syndrome to fruits and vegetables. Acorn and wood dust from oak can cause allergic disease. We summarize the distribution and taxonomic classification of oak trees of allergenic importance. Molecular characteristics of the identified component allergens, cross-reactivity, and clinical aspects for diagnosis and immunotherapy are also described with an emphasis on Korean situations.

Relationship among airborne pollen, sensitization, and pollen food allergy syndrome in Asian allergic children.

Causes of pediatric pollen food allergy syndrome (PFAS) differ depending on airborne pollen levels in a particular region. We aimed to analyze airborne pollen counts, IgE sensitization rates, and PFAS incidence among children with allergies in South Korea and Japan. This cross-sectional study included children aged 5-17 years with allergies in 2017. Airborne pollen samples were collected from Busan in South Korea, and Fukuoka and Tochigi in Japan. Questionnaires were used to assess bronchial asthma, seasonal allergic rhinitis, atopic dermatitis, food allergy, and PFAS. The serum IgE specific to Dermatophagoides pteronyssinus, pollen, tomato, and peach were investigated. In total, 57, 56, and 20 patients from Busan, Fukuoka, and Tochigi, respectively, were enrolled. Airborne Japanese cedar and cypress pollen were predominant in Fukuoka and Tochigi, whereas pine and alder pollen were predominant in Busan. Children with allergies in Fukuoka and Tochigi had a significantly higher sensitization rate to Japanese cedar, cypress, juniper, orchard grass, ragweed, Japanese hop, and tomato compared with children in Busan. In Fukuoka and Tochigi, where Japanese cedar and cypress pollen were frequently scattered, high sensitizations among allergic children were observed. The sensitization rate was not affected by the pollen count in alder, grass, ragweed, and Japanese hop. In multivariable analysis, only alder sensitization was found to be associated with PFAS (odds ratio: 6.62, 95% confidence interval: 1.63-26.87, p = 0.008). In patients with PFAS in Busan and Tochigi, peach associated with birch allergen Bet v 1 was a causative food item for PFAS. Moreover, PFAS was associated with ragweed and Japanese hop pollen sensitization in Fukuoka. Regardless of pollen counts, alder pollen sensitization was associated with PFAS in children. Ragweed and Japanese hop pollen sensitization were associated with PFAS, particularly among children in southern Japan.

Recent Advances in the Allergic Cross-Reactivity between Fungi and Foods.

Airborne fungi are one of the most ubiquitous kinds of inhalant allergens which can result in allergic diseases. Fungi tend to grow in warm and humid environments with regional and seasonal variations. Their nomenclature and taxonomy are related to the sensitization of immunoglobulin E (IgE). Allergic cross-reactivity among different fungal species appears to be widely existing. Fungus-related foods, such as edible mushrooms, mycoprotein, and fermented foods by fungi, can often induce to fungus food allergy syndrome (FFAS) by allergic cross-reactivity with airborne fungi. FFAS may involve one or more target organs, including the oral mucosa, the skin, the gastrointestinal and respiratory tracts, and the cardiovascular system, with various allergic symptoms ranging from oral allergy syndrome (OAS) to severe anaphylaxis. This article reviews the current knowledge on the field of allergic cross-reactivity between fungal allergens and related foods, as well as the diagnosis and treatment on FFAS.

Development of mouse model for oral allergy syndrome to identify IgE cross-reactive pollen and food allergens: ragweed pollen cross-reacts with fennel and black pepper.

Oral allergy syndrome (OAS) is an IgE-mediated immediate food allergy that is localized to the oral mucosa. Pollen food allergy syndrome (PFAS), a pollinosis-associated OAS, is caused by cross-reactivity between food and pollen allergens. However, we need to more precisely understand the underlying pathogenesis of OAS/PFAS. In the present study, we developed a method to comprehensively identify cross-reactive allergens by using murine model of OAS and protein microarray technology. We focused on lip angioedema, which is one of the most common symptoms of OAS, and confirmed that mast cells reside in the tissues inside the lower lip of the mice. Interestingly, when the food allergen ovalbumin (OVA) was injected inside the lower lip of mice with high levels of OVA-specific IgE followed by an intravenous injection of the Evans blue dye, we found immediate dye extravasation in the skin of the neck in a mast cell-dependent manner. In addition, the degree of mast cell degranulation in the oral cavity, reflecting the severity of oral allergic responses, can be estimated by measuring the amount of extravasated dye in the skin. Therefore, we used this model of OAS to examine IgE cross-reactive allergens in vivo. Protein microarray analysis showed that serum IgE from mice intraperitoneally sensitized with ragweed pollen, one of the major pollens causing pollinosis, bound highly to protein extracts from several edible plants including black peppercorn and fennel. We confirmed that the levels of black pepper-specific IgE and fennel-specific IgE were significantly higher in the serum from ragweed pollen-sensitized mice than in the serum from non-sensitized control mice. Importantly, analysis of murine model of OAS showed that the injection of black pepper or fennel extract induced apparent oral allergic responses in ragweed pollen-sensitized mice. These results indicate IgE cross-reactivity of ragweed pollen with black pepper and fennel. In conclusion, we developed mouse model of OAS to identify IgE cross-reactive pollen and food allergens, which will help understand the pathogenesis of OAS/PFAS.

A practical focus on oral immunotherapy to tree nuts.

Tree nut (TN) allergy is common, with a global prevalence of up to 4.9%. TN allergy is persistent in most patients, and accidental reactions are common. There is considerable clinical cross-reactivity between cashew and pistachio, and between walnut and pecan. A diagnosis of TN allergy is based on a history of clinical reaction on ingestion, along with confirmed sensitization through either skin-prick or serum immunoglobulin E (IgE) testing. Component testing and food challenges may be required in patients with birch pollinosis to distinguish between IgE-mediated allergy to a heat-stable protein and pollen food allergy syndrome. There is available evidence that TN oral immunotherapy (OIT) is reasonably safe and effective. There are numerous nonpharmaceutical food products to facilitate TN-OIT dosing. TN OIT should be offered as a treatment option for patients with TN allergy.