Delayed symptoms and orthostatic intolerance following peanut challenge.

BACKGROUND: Clinical reactions to Oral Food Challenge (OFC) in peanut-allergic individuals have been well-characterised, but rates and phenotypes of symptom recurrence beyond the first hour after objective symptoms are less well-characterised. OBJECTIVE: To evaluate the rate of new-onset symptoms occurring at least 1 h after stopping OFC in peanut-allergic children and adults undergoing peanut-OFC. METHODS: We prospectively collected data relating to adverse events following positive reactions at double-blind, placebo-controlled food challenges (DBPCFC) to peanut in children and adults evaluated for eligibility to participate in two clinical trials (NCT02149719, NCT02665793). The trials included people aged 8 to 45 with primary, IgE-mediated peanut allergy at DBPCFC. The challenge protocol included consumption of a light meal 1 h after reaction. RESULTS: A total of 121 participants (64 children, 57 adults) had immediate, objective symptoms at DBPCFC, 25 (17 children, 8 adults) with anaphylaxis. Thirty-three (27%) had progression or recurrence of symptoms ≥ 1 h after objective clinical reaction, of whom 8 developed anaphylaxis. In 23 cases, the onset of new symptoms was associated with consumption of a light meal. In eight cases, symptoms were limited to a symptomatic postural fall in blood pressure noted in preparation for discharge, without any other new features of an allergic reaction. CONCLUSIONS & CLINICAL RELEVANCE: Progressive or new-onset symptoms ≥1 h following initial allergic reaction at OFC are common and can include orthostatic hypotension. Recurrent symptoms may be temporally associated with food consumption.

Sensitization to peanut, egg or pets is associated with skin barrier dysfunction in children with atopic dermatitis.

BACKGROUND: Children with atopic dermatitis (AD) are often sensitized to food and aeroallergens, but sensitization patterns have not been analysed with biologic measures of disease pathogenicity. OBJECTIVE: We sought to define allergen sensitization grouping(s) using unbiased machine learning and determine their associations with skin filaggrin (FLG) and transepidermal water loss (TEWL) (assesses skin barrier integrity), S100A8 and S100A9 expression (assesses skin inflammation) and AD severity. METHODS: We studied 400 children with AD in the Mechanisms of Progression from Atopic Dermatitis to Asthma in Children (MPAACH) cohort to identify groupings of food and aeroallergen sensitizations. MPAACH is a paediatric AD cohort, aged 1-2, recruited through hospital/community settings between 2016 and 2018. We analysed these groupings' associations with AD biomarkers: skin FLG, S100A8 and S100A9 expression, total IgE, TEWL and AD severity. RESULTS: An unbiased machine learning approach revealed five allergen clusters. The most common cluster (N = 131), SPTPEP, had sensitization to peanut, egg and/or pets. Three low prevalence clusters, which included children with allergen sensitization other than peanut, egg or pets, were combined into SPTOther . SPTNEG included children with no sensitization(s). SPTPEP children had higher median non-lesional TEWL (16.9 g/m2 /h) and IgE (90 kU/L) compared with SPTOTHER (8.8 g/m2 /h and 24 kU/L; p = .01 and p < .001) and SPTNEG (9 g/m2 /h and 26 kU/L; p = .003 and p < .001). SPTPEP children had lower median lesional (0.70) and non-lesional (1.09) FLG expression compared with SPTOTHER (lesional: 0.9; p = .047, non-lesional: 1.78; p = .01) and SPTNEG (lesional: 1.47; p < .001, non-lesional: 2.21; p < .001). There were no differences among groupings in S100A8 or S100A9 expression. CONCLUSIONS AND CLINICAL RELEVANCE: In this largely clinic-based cohort of young children with AD, allergic sensitization to peanut, egg, cat or dog was associated with more severe disease and skin barrier function but not markers of cutaneous inflammation. These data need replicating in a population-based cohort but may have important implications for understanding the interaction between AD and allergic sensitization.

Cardiovascular changes during peanut-induced allergic reactions in human subjects.

BACKGROUND: Food allergy is the most common cause of anaphylaxis. Changes in posture during acute reactions can trigger fatal outcomes, but the impact of allergic reactions on the cardiovascular system in nonfatal reactions remains poorly understood. OBJECTIVE: Our aim was to systematically evaluate changes in cardiovascular function during acute allergic reactions to peanut. METHODS: Participants underwent double-blind placebo-controlled food challenge to peanut as part of a clinical trial. Changes in hemodynamic parameters (heart rate, stroke volume, blood pressure, and peripheral blood flow) and electrocardiogram findings during food challenges were assessed using noninvasive continuous monitoring. RESULTS: A total of 57 adults (median age 24 years [interquartile range = 20-29]), 53% of whom were female, participated; 22 (39%) had anaphylaxis. Acute reactions were associated with significant changes in stroke volume (mean decrease of 4.2% [95% CI = 0.8-7.6; P = .03]), heart rate (mean increase 11.6% [95% CI = 8.4-14.8; P < .0001]), and peripheral blood flow (mean increase 19.7% [95% CI = 10.8-28.6; P < .0001]), irrespective of reaction severity. These changes were reproduced at a subsequent repeat peanut challenge in 26 participants, and could be reversed with administration of intravenous fluids which resulted in faster resolution of abdominal symptoms. CONCLUSIONS: In this first detailed human study of cardiovascular changes during food-induced allergic reactions, we found evidence for significant fluid redistribution, independent of reaction severity. This provides a sound rationale for optimizing venous return during significant allergic reactions to food. Finally, these data provide a new paradigm for understanding severity in anaphylaxis, in which poor outcomes may occur as a result of a failure in compensatory mechanisms.

Food-induced anaphylaxis in infancy compared to preschool age: A retrospective analysis.

OBJECTIVE: Little is known regarding food anaphylaxis in infancy. We aimed to describe specificities of food anaphylaxis in infants (≤12 months) as compared to preschool children (1-6 years). METHODS: We conducted a retrospective study of all food anaphylaxis cases recorded by the Allergy Vigilance Network from 2002 to 2018, in preschool children focusing on infants. RESULTS: Of 1951 food anaphylaxis reactions, 61 (3%) occurred in infants and 386 (20%) in preschool children. Two infants had two anaphylaxis reactions; thus, we analyzed data among 59 infants (male: 51%; mean age: 6 months [SD: 2.9]); 31% had a history of atopic dermatitis, 11% of previous food allergy. The main food allergens were cow's milk (59%), hen's egg (20%), wheat (7%) and peanut (3%) in infants as compared with peanut (27%) and cashew (23%) in preschool children. Anaphylaxis occurred in 28/61 (46%) cases at the first cow's milk intake after breastfeeding discontinuation. Clinical manifestations were mainly mucocutaneous (79%), gastrointestinal (49%), respiratory (48%) and cardiovascular (21%); 25% of infants received adrenaline. Hives, hypotension and neurologic symptoms were more likely to be reported in infants than in preschool children (P = .02; P = .004; P = .002, respectively). Antihistamines and corticosteroids were more often prescribed in preschool children than in infants (P = .005; P = .025, respectively). CONCLUSION: Our study found that in infants presenting with their first food allergy, in a setting with a high rate of infant formula use, the most predominant trigger was cow's milk. As compared to older preschool children, hives, hypotonia and hypotension were more likely to be reported in infants. We believe that this represents a distinct food anaphylaxis phenotype that can further support developing the clinical anaphylaxis criteria in infants.

Effect of sleep deprivation and exercise on reaction threshold in adults with peanut allergy: A randomized controlled study.

BACKGROUND: Peanut allergy causes severe and fatal reactions. Current food allergen labeling does not address these risks adequately against the burden of restricting food choice for allergic patients because of limited data on thresholds of reactivity and the influence of everyday factors. OBJECTIVE: We estimated peanut threshold doses for a United Kingdom population with peanut allergy and examined the effect of sleep deprivation and exercise. METHODS: In a crossover study, after blind challenge, participants with peanut allergy underwent 3 open peanut challenges in random order: with exercise after each dose, with sleep deprivation preceding challenge, and with no intervention. Primary outcome was the threshold dose triggering symptoms (in milligrams of protein). Primary analysis estimated the difference between the nonintervention challenge and each intervention in log threshold (as percentage change). Dose distributions were modeled, deriving eliciting doses in the population with peanut allergy. RESULTS: Baseline challenges were performed in 126 participants, 100 were randomized, and 81 (mean age, 25 years) completed at least 1 further challenge. The mean threshold was 214 mg (SD, 330 mg) for nonintervention challenges, and this was reduced by 45% (95% CI, 21% to 61%; P = .001) and 45% (95% CI, 22% to 62%; P = .001) for exercise and sleep deprivation, respectively. Mean estimated eliciting doses for 1% of the population were 1.5 mg (95% CI, 0.8-2.5 mg) during nonintervention challenge (n = 81), 0.5 mg (95% CI, 0.2-0.8 mg) after sleep, and 0.3 mg (95% CI, 0.1-0.6 mg) after exercise. CONCLUSION: Exercise and sleep deprivation each significantly reduce the threshold of reactivity in patients with peanut allergy, putting them at greater risk of a reaction. Adjusting reference doses using these data will improve allergen risk management and labeling to optimize protection of consumers with peanut allergy.

Severity of peanut allergy and the unmet gaps in care: a call to action.

Peanut allergy is one of the most common food allergies in children, with a prevalence that has been increasing over the past several decades. The allergy is a type I, immunoglobulin E (IgE)-mediated reaction that commonly presents in childhood and can be associated with an anaphylactic response. There are many theories that attempt to explain the increasing prevalence, including dietary changes, improvements in hygiene, and intentional allergen avoidance. Diagnosis is made through a combination of a thorough patient history, peanut-specific serum-specific IgE levels, peanut skin-prick test, and, if necessary, an oral food challenge. Guidelines based on the landmark 2015 Learning Early About Peanut Allergy trial suggest that peanuts should be introduced into the diet as early as 4 to 6 months of age in infants who are at highest risk of developing peanut allergy. It is important for providers to recognize risk factors for the development of peanut allergy, identify associated clinical symptoms, and provide an accurate diagnosis of patients to effectively manage them and their families and prevent future reactions.

Food allergy to previously tolerated foods: Course and patient characteristics.

BACKGROUND: The acquisition of food allergy (FA) to previously safely consumed basic food proteins is an unusual presentation of immunoglobulin E (IgE)-mediated allergic disease. OBJECTIVE: We sought to characterize patients who developed FA to previously tolerated foods (FA-PTF), including underlying reasons for and length of elimination diet of previously tolerated foods. METHODS: Patients (n = 30) with complaints consistent with FA to foods previously consumed safely were evaluated. Clinical history was obtained, and skin prick testing and graded oral food challenges (OFC) were performed. One fatal case of FA-PTF was reported by a physician. RESULTS: Twenty-two of 30 patients (ages 1.2-50 years) were diagnosed with FA-PTF by OFC to milk (n = 17), egg (n = 2), and peanuts (n = 3). One additional patient with FA-PTF had a fatal reaction to milk. Anaphylactic reactions were reported in 12 of these 23 FA-PT patients (52%); 8 experienced multiple episodes. Atopic dermatitis was diagnosed in 52% (12/23) of patients, 8 of 12 as severe; overall, 18 of 23 (78%) of patients had marked personal atopic background. Sixteen patients (70%) initiated an elimination diet, 12 of whom did so on advice from a health care provider, before the appearance of allergic symptoms. However, in 4 patients with FA-PTF, reactivity to the food protein emerged during uninterrupted consumption. CONCLUSION: Food allergy to previously tolerated foods primarily appears after an elimination diet in atopic patients. Anaphylactic reactions are common. Health care providers should consider these risks before recommending elimination diet of tolerated foods.

Caregiver and expecting caregiver support for early peanut introduction guidelines.

BACKGROUND: Recent guidelines recommend early peanut introduction (EPI) beginning around 4 to 6 months of age in infants with severe eczema and/or egg allergy and around 6 months for all other infants. Caregiver preferences for such practices are unknown. OBJECTIVE: To determine levels of support for early allergenic solid food recommendations among new and expecting caregivers of infants at risk for peanut allergy. METHODS: We explored preferences for EPI and in-office allergy risk assessment (IRA) through a nationally representative survey of expecting (n = 1,000) and new caregivers of infants younger than 1 year (n = 1,000). RESULTS: Among a primarily female (99.7%), married (80.3%), and white (74.4%) sample, 29% had no or vague awareness of the new guidelines, 61% had no or minimal concern for their child developing food allergy, but 54% felt timing of food introduction has moderate to strong importance for developing food allergy. Only 31% expressed willingness for EPI before or around 6 months of age, with 40% reporting willingness to introduce peanut after 11 months of age, similar to tree nuts and seafood. However, 60% reported willingness to introduce egg before 8 months of age. A total of 51% and 56.8% were unwilling to allow IRA methods, such as skin testing and oral challenge, before 11 months of age, respectively. Odds of willingness to delay peanut introduction (odds ratio, 0.79; 95% confidence interval, 0.65-0.96) and undergo challenge (odds ratio, 0.67; 95% confidence interval, 0.54-0.82) after 6 months of age were lower among expecting caregivers. CONCLUSION: Among new and expecting caregivers, there is poor current willingness and questionable support for early allergenic solid food recommendations, including IRA before introduction. Willingness was better among expecting vs current caregivers. These trends underscore a need for broader formal implementation planning to facilitate early allergen introduction and maximize its preventive benefits.

Environmental exposure to peanut and the risk of an allergic reaction.

OBJECTIVE: To review the evidence of the risk of environmental exposure to peanut to a peanut allergic individual. DATA SOURCES AND STUDY SELECTION: A narrative review was performed using a PubMed search of relevant articles involving peanut environmental distribution, environmental peanut abatement, and public policy regarding peanut restriction. RESULTS: Data from 4 studies have shown that peanut butter vapors and smeared peanut butter on skin do not cause systemic reactions, that peanut can be abated from hands and surfaces using appropriate cleaning agents, and that shelled peanut dust does not become airborne. Studies have recently confirmed dose of 1.5 mg of peanut protein would be generally tolerated by approximately 95% of the peanut-allergic population based on objective symptoms in challenge-based studies, affirming earlier research. Restrictive policies that focus on bans (or restricted presence in certain areas) of peanuts or peanut-containing products in environments such as schools or on commercial aircraft are not backed by evidence that such measures work, which may raise an uncomfortable clash between accommodations that lack any medical evidence of necessity and a desire to provide measures that comfort our patients. CONCLUSION: There is little risk posed from non-oral exposure to peanut in the environment, from casual contact, proximity, or inhalation. If 5% of the population may tolerate a threshold of approximately 1.5 mg of peanut protein, this may help liberate behavior and situational-decision making regarding the necessity of certain avoidances and restrictions. Continued work is needed to dispel myths about the mechanisms of how peanut may induce an allergic reaction.

Boiling and Frying Peanuts Decreases Soluble Peanut (Arachis Hypogaea) Allergens Ara h 1 and Ara h 2 But Does Not Generate Hypoallergenic Peanuts.

Peanut allergy continues to be a problem in most developed countries of the world. We sought a processing method that would alter allergenic peanut proteins, such that allergen recognition by IgE from allergic individuals would be significantly reduced or eliminated. Such a method would render accidental exposures to trace amounts of peanuts safer. A combination of boiling and frying decreased recovery of Ara h 1 and Ara h 2 at their expected MWs. In contrast, treatment with high pressures under varying temperatures had no effect on protein extraction profiles. Antibodies specific for Ara h 1, Ara h 2, and Ara h 6 bound proteins extracted from raw samples but not in boiled/fried samples. However, pre-incubation of serum with boiled/fried extract removed most raw peanut-reactive IgE from solution, including IgE directed to Ara h 1 and 2. Thus, this method of processing is unlikely to generate a peanut product tolerated by peanut allergic patients. Importantly, variability in individual patients' IgE repertoires may mean that some patients' IgE would bind fewer polypeptides in the sequentially processed seed.

Oral immunotherapy for management of peanut allergy in spanish children

No disponible

High-resolution Orbitrap™-based mass spectrometry for rapid detection of peanuts in nuts.

Peanut represents one of the most harmful allergenic foods capable of triggering severe and sometimes lethal reactions in allergic consumers upon ingestion of even small amounts. Several proteins capable of inducing allergic reactions that have been recognised by patients' IgE antibodies have been identified from this nut source. Methods mainly based on ELISA assays have been developed in order to detect peanuts in several food commodities. In addition LC-MS/MS methods based on different mass analysers have also been devised for tracing peanut contamination in different foods achieving low limits of detection. The applicability of a benchtop high-resolution Exactive™ mass spectrometer has never been investigated for the rapid screening of peanut contamination in complex food matrices like mixtures of nuts. We report in this paper the design of suitable peanut markers and the development of an high-resolution Orbitrap™ mass spectrometer-based method for peanut detection in a mixture of nuts species. With this aim, different types of samples were prepared: (1) nuts-based powder made up of a mixture of hazelnuts, pistachios, almonds and walnuts; and (2) nuts powder fortified with peanuts. Different levels of fortifications were produced and the applicability of the method was tested. Finally, a subset of six peptides fulfilling specific analytical requirements was chosen to check the suitability of the method tailored to the detection of peanuts in nuts-based products, and two of them, peptides VYD and WLG, were selected as quantitative markers. The method proved to be a suitable screening tool to assess the presence of traces of peanuts in other tree nuts with a limit of detection as low as 4 µg of peanuts proteins or 26 µg of peanuts in 1 g of matrix.

Utility of specific IgE to Ara h 6 in peanut allergy diagnosis.

BACKGROUND: Specific IgE to Ara h 2 has been shown to be useful in the diagnosis of peanut allergy, whereas the peanut lipid transfer protein, Ara h 9, has been suggested to be responsible for peanut allergy in the Mediterranean population. OBJECTIVE: To better characterize peanut allergy in children from a Mediterranean area and determine the value of specific IgE to Ara h 6 (conglutinin, 2S albumin) for the diagnosis of peanut allergy. METHODS: Ninety-one children with suspected allergy to edible vegetables were included in the study. They were classified as allergic or tolerant to peanut. Specific IgE to peanut allergens was measured by a commercially available microarray (ImmunoCAP ISAC 112, ThermoFisher, Uppsala, Sweden). RESULTS: Patients allergic to peanut showed positive specific IgE changes to peanut seed storage proteins (Ara h 1, Ara h 2, Ara h 3, and Ara h 6) more frequently than tolerant subjects. Ara h 9 showed a similar frequency of reactivity in the 2 groups. Ara h 6 was the allergen most frequently recognized by patients with allergy. Four patients with allergy were found to be mono-sensitized to Ara h 6. Ara h 2 and Ara h 6 showed similar diagnostic accuracy (areas under the curve 0.792 and 0.852). A combined cutoff point for Ara h 2 (≥0.1 ISU) and Ara h 6 (≥2 ISU) yielded the best diagnostic performance (sensitivity 0.77, specificity 0.97, positive predictive value 0.89, negative predictive value 0.93). CONCLUSION: Peanut allergy cannot be ruled out without obtaining a negative determination of Ara h 6.

Component-resolved IgE profiles in Austrian patients with a convincing history of peanut allergy.

BACKGROUND: Peanut allergy develops after primary sensitization to peanut allergens and/or IgE cross-sensitization with homologous allergens from various plants. Therefore, heterogeneous patterns of sensitization to individual peanut allergens are observed in different countries. The aim of this study was to examine the IgE sensitization patterns of Austrian peanut-allergic patients. METHODS: Sera from 65 peanut-allergic patients and 20 peanut-tolerant atopics were obtained in four Austrian allergy clinics. Sensitization patterns against peanut allergens Ara h 1-3, 6, 8 and 9 were identified by ImmunoCAP and ImmunoCAP ISAC. RESULTS: Austrian peanut-allergic patients were sensitized to Ara h 2 and 6 (71%), followed by Ara h 1 (62%), Ara h 8 (45%), Ara h 3 (35%) and Ara h 9 (11%). All sera containing Ara h 2-specific IgE were also positive for Ara h 6, with Ara h 6-specific IgE levels significantly (p < 0.05) higher compared with Ara h 2. Twelve percent displayed IgE reactivity exclusively to Ara h 8. Peanut extract and Ara h 8 showed low diagnostic specificities of 25 and 10%, respectively. The other peanut allergens showed 100% specificity. Diagnostic sensitivities determined by ImmunoCAP ISAC and ImmunoCAP were highly similar for Ara h 2, 3 and 8. CONCLUSIONS: The majority of symptomatic peanut-allergic patients are sensitized to Ara h 2 and Ara h 6. In peanut-symptomatic patients with additional birch pollen allergy, other peanut allergens, especially Ara h 8, should be tested when IgE reactivity to Ara h 2 is absent.

Administration of a probiotic with peanut oral immunotherapy: A randomized trial.

BACKGROUND: Coadministration of a bacterial adjuvant with oral immunotherapy (OIT) has been suggested as a potential treatment for food allergy. OBJECTIVE: To evaluate a combined therapy comprising a probiotic together with peanut OIT. METHODS: We performed a double-blind, placebo-controlled randomized trial of the probiotic Lactobacillus rhamnosus CGMCC 1.3724 and peanut OIT (probiotic and peanut oral immunotherapy [PPOIT]) in children (1-10 years) with peanut allergy. The primary outcome was induction of sustained unresponsiveness 2 to 5 weeks after discontinuation of treatment (referred to as possible sustained unresponsiveness). Secondary outcomes were desensitization, peanut skin prick test, and specific IgE and specific IgG4 measurements. RESULTS: Sixty-two children were randomized and stratified by age (≤5 and >5 years) and peanut skin test wheal size (≤10 and >10 mm); 56 reached the trial's end. Baseline demographics were similar across groups. Possible sustained unresponsiveness was achieved in 82.1% receiving PPOIT and 3.6% receiving placebo (P < .001). Nine children need to be treated for 7 to achieve sustained unresponsiveness (number needed to treat, 1.27; 95% CI, 1.06-1.59). Of the subjects, 89.7% receiving PPOIT and 7.1% receiving placebo were desensitized (P < .001). PPOIT was associated with reduced peanut skin prick test responses and peanut-specific IgE levels and increased peanut-specific IgG4 levels (all P < .001). PPOIT-treated participants reported a greater number of adverse events, mostly with maintenance home dosing. CONCLUSION: This is the first randomized placebo-controlled trial evaluating the novel coadministration of a probiotic and peanut OIT and assessing sustained unresponsiveness in children with peanut allergy. PPOIT was effective in inducing possible sustained unresponsiveness and immune changes that suggest modulation of the peanut-specific immune response. Further work is required to confirm sustained unresponsiveness after a longer period of secondary peanut elimination and to clarify the relative contributions of probiotics versus OIT.

Specific epicutaneous immunotherapy prevents sensitization to new allergens in a murine model.

BACKGROUND: Allergy to cow's milk increases the risk of sensitization to other foods in young children. OBJECTIVES: We sought to evaluate the effect of early epicutaneous immunotherapy (EPIT) on further sensitization to peanut or house dust mite (HDM) in a murine model of sensitization to cow's milk. METHODS: BALB/c mice orally sensitized to milk were epicutaneously treated with a Viaskin patch (DBV Technologies) loaded with milk proteins for 8 weeks. Mice were then sensitized to peanut or HDM. After sensitization to peanut, mice were exposed to a peanut regimen known to induce eosinophilic esophageal inflammation. After sensitization to HDM, mice were challenged with aerosols to HDM, and airway hyperresponsiveness was evaluated by using plethysmography. Humoral response was also analyzed. The role of regulatory T (Treg) cells was evaluated by adoptively transferring Treg cells from milk EPIT-treated mice to naive mice before sensitization to peanut. Protection against anaphylaxis was also investigated. Methylation of the promoter region of transcription factors was analyzed by using PCR assays. RESULTS: In milk-sensitized mice specific EPIT prevented further sensitization to peanut or HDM. EPIT significantly modified the humoral response, reduced TH2 cytokine levels, decreased eosinophilic esophageal infiltration, and suppressed airway hyperresponsiveness. The protective effect was sustained over 2 months. Moreover, the adoptive transfer of milk EPIT Treg cells completely prevented sensitization to peanut and peanut-induced anaphylaxis. Milk EPIT enhanced methylation of the GATA-3 promoter region. CONCLUSIONS: Our results showed that EPIT influences the natural history of allergy and reduces the risk of further sensitization through a Treg cell-dependent mechanism.

Alergia alimentaria a maní: conceptos clínicos, diagnósticos y terapéuticos / Food allergy to peanuts: clinical, diagnostic and therapeutic concepts

The prevalence of food allergy (FA) is about 2-8 percent, with clinical manifestations ranging from localized symptoms, to severe anaphylactic reactions. FA is generally caused by milk, eggs, soybeans, tree nuts, peanuts, wheat, fish and crustacean; being peanut one of the main foods involved in Western countries. Although in other parts of the world peanut allergy (PA) is not a problem, probably due to timing of introduction into the diet, form and preparation, genetics, and the hygiene hypothesis. Unfortunately, in Chile there are no epidemiological data about FA or PA. A number of food allergens have been identified, which has improved patient diagnosis and treatment assessment. Regarding peanut, 9 allergens have been identified, Ara h 1 to Ara h 9 (Arachis hypogaea). The diagnosis of IgE-mediated PA is based on a consistent history and evidence of peanut-specific IgE sensitization, carried out by skin-prick testing or in vitro determination. PA treatment consists of peanuts avoidance, which often becomes difficult due to inadvertent consumption. Today promising treatments are under development, including oral induction tolerance or sublingual immunotherapy. These treatments offer the possibility of at least raising the threshold of the amount of peanut that would be necessary to cause a life-threatening allergic reaction.

Relation between eosinophilic esophagitis and oral immunotherapy for food allergy: a systematic review with meta-analysis.

BACKGROUND: The onset of eosinophilic esophagitis (EoE) after oral immunotherapy (OIT) has been repeatedly described in patients with immunoglobulin E (IgE)-mediated food allergy in recent years, but the relation between the 2 conditions has not been fully assessed and quantified. OBJECTIVE: To provide a systematic review of the evidence for an association between OIT and EoE. METHODS: Electronic searches were performed with keywords relating to EoE and OIT in the MEDLINE, EMBASE, and SCOPUS databases. Summary estimates were calculated. A fixed-effects model was used depending on heterogeneity (I(2)). Risk of publication bias was assessed by funnel plot analysis and the Egger test. RESULTS: The search yielded 118 documents, 15 of which were included in the quantitative summary. Most reported information came from children undergoing peanut, milk, and egg OIT. Significant publication bias in favor of studies reporting the development of EoE after OIT was documented. The overall prevalence of EoE after OIT was 2.7% (95% confidence interval 1.7%-4.0%, I(2) = 0%). Differences between medium-to high-quality studies and those of low quality were documented (3.5% vs 2.5%, respectively). EoE often resolved after OIT discontinuation; histologic remission of EoE achieved after allergen immunotherapy also was documented in 2 patients whose topical fluticasone treatment failed. CONCLUSION: New onset of EoE after OIT occurs in up to 2.7% of patients with IgE-mediated food allergy undergoing this treatment strategy. The limited data on the utility of allergen immunotherapy as a therapy for EoE prevent a recommendation for this treatment option.