Oral Food Challenge Outcomes Research Articles

Randomized Trial of Early Infant Formula Introduction to Prevent Cow’s Milk Allergy

To determine if the early introduction of cow’s milk formula (CMF) could prevent the development of cow’s milk allergy (CMA) in healthy infants.In the study, the researchers enrolled 491 newborns within 5 days of birth from 4 hospitals in Okinawa, Japan. Inclusion criteria were a gestational age of at least 35 weeks, a birth weight of at least 2000 g, and the absence of severe underlying disease.Participants were allowed to supplement with CMF before 1 month of age and underwent a screening oral food challenge (OFC) at that time. Those with a negative OFC result were randomly assigned to either the open-label CMF ingestion or avoidance. Those in the CMF ingestion group ingested at least 10 mL of CMF daily between 1 and 2 months of age, whereas those in the avoidance group were instructed to supplement with soy formula if needed during this time. At 3 months of age, an open OFC was performed on all participants. Those who were negative from both groups spontaneously ingested CMF to supplement breastfeeding until 6 months of age, at which time a second open OFC was performed on all participants.The modified intention-to-treat analysis revealed a significantly lower rate of CMA in the ingestion group versus the avoidance group at 6 months of age (0.8% vs 6.8%; respectively; P < .001). Approximately 70% were still breastfed, and no mothers had eliminated cow’s milk. There were no differences in the rate of eczema or sensitization to egg, wheat, or soy between groups.Daily ingestion of at least 10 mL of CMF between 1 and 2 months of life decreased the rate of OFC-confirmed CMA in infants. The early introduction of CMF did not impede breastfeeding.Data supporting the benefit of early introduction of allergenic foods in preventing allergy are accumulating. In this study, researchers examined the impact of introducing a specific daily minimum quantity of CMF in the general infant population, with favorable results. In further studies, researchers could provide interventions in a blinded manner and/or examine the impact of CMF introduction in infants at high-risk of allergy.

First Real-World Effectiveness Analysis of Preschool Peanut Oral Immunotherapy

To examine the effectiveness and safety of peanut oral immunotherapy (POIT) after 1 year of maintenance in preschool-aged children.In the study, researchers included 161 patients aged 9 to 70 months who successfully completed 1 year of maintenance POIT and were eligible for follow-up oral food challenge (OFC). The inclusion criteria were having a history of objective reaction to peanut and a positive test result (either a skin-prick test [SPT] or peanut-specific immunoglobulin E [ps-IgE]) or at least 1 objective reaction with dosing during build-up, along with a predetermined ps-IgE level and SPT wheal size.Preschoolers enrolled in the study were given gradually increasing peanut protein doses over 16–22 weeks at clinic visits, building up to a maintenance dose of 300 mg. The children then ingested 300 mg of peanut protein daily for a year. After ∼12 months, the participants were invited to participate in a follow-up peanut OFC. SPT and/or ps-IgE were obtained at baseline and selectively throughout the maintenance and follow-up OFC visits. Symptoms of allergic reactions occurring were recorded and graded 1 to 5.Of the patients who received a year of maintenance therapy and underwent follow-up OFC (n = 117), 92 (78.6%) tolerated a cumulative dose of 4000 mg peanut protein without any symptoms, and 115 (98.3%) tolerated at least 1000 mg. The dose tolerated had increased on average by 3969 mg in those with a negative follow-up OFC and by 3376 mg in those with a positive follow-up OFC. SPT wheal size was also significantly decreased after a year regardless of follow-up OFC result; however, the decrease in ps-IgE was not statistically significant. Those with reactions at the follow-up OFC had either grade 1 (14.5% of all who underwent OFC), grade 2 (6%), or grade 3 (0.85%). No one had a grade 4 or 5 reaction. Of the 124 patients with safety outcomes analyzed during maintenance therapy, 111 (89.5%) were symptom-free during POIT dosing, 10 (8.1%) had grade 1 reactions, 3 (2.4%) had grade 2 reactions, and only 2 (1.6%) required epinephrine for POIT dosing reactions.POIT is effective for preschoolers, protecting against at least 1000 mg peanut protein exposure after one year of maintenance therapy in 98.3% of children and allowing consumption of up to 4000 mg in 78.6%. It is also safe during maintenance, with nearly 90% of children symptom-free during maintenance dosing.POIT has emerged as a patient-preference–sensitive option to increase tolerance to peanut protein and protect against accidental exposure. Previous studies have revealed that increasing the peanut threshold to 1000 mg provides 99% protection from accidental exposures, and commercial POIT product is now approved in children 4 to 17 years old. This is the first real-world study revealing that the majority of preschoolers (98.3%) are able to tolerate 1000 mg after a year of POIT maintenance therapy. Mounting evidence suggests POIT may be safer and more effective when initiated at younger ages, likely because of a milder allergic phenotype, less patient aversion, and opportunity for better adherence from close parental supervision. Preschool POIT is a promising disease-modifying intervention that, in the context of shared decision-making with an experienced pediatric allergist, is likely to dramatically improve health and economic outcomes for patients and families.

Utility of Gal d 1-Specific IgE Levels in Predicting Reactivity to Boiled Egg in Chinese Children

Background: Many researchers have reported predicting the outcome of oral food challenges (OFCs) on the basis of specific IgE (sIgE) levels. However, the clinical usefulness of the determination of IgE antibodies to egg allergen components in Chinese children with suspected boiled egg allergy is not well studied. Objective: Our objective was to assess the diagnostic performance of sIgE to egg white and Gal d 1, 2, 3, and 5 based on the open challenge outcome for boiled egg. Methods: A total of 48 child patients with a suspect of boiled egg allergy were included. Serum egg white and Gal d 1, 2, 3, and 5 sIgE were measured by ImmunoCAP. Diagnostic value was assessed by area under the receiver operating characteristic curves (AUC). Results: Using the OFC results as the reference parameter, Gal d 1 sIgE had the highest AUC (0.84) compared with egg white (0.77) and other investigated components (ranging from 0.51 to 0.71). The clinical sensitivity and specificity for the sIgE to Gal d 1 at optimal cutoff (6.15 kUA/L) were 73.7% and 96.7%, respectively. Sensitization to Gal d 1 with a cutoff value of >7.48 kUA/L indicated a 90% probability of positive challenge. Conclusion: Quantitative measurements of Gal d 1 sIgE antibodies using ImmunoCAP are useful in the management of boiled egg allergy in Chinese children.

Factors influencing reintroduction of peanut and tree nuts after negative oral food challenges in children

BackgroundCompliance with reintroduction of foods after a negative oral food challenge (OFC) is variable. Ongoing avoidance of tolerated foods is associated with recurrence of allergy and a reduced quality of life. ObjectiveTo determine the proportion of children who reintroduced peanut or tree nuts after a negative OFC and to describe factors that influenced decisions regarding reintroduction or avoidance of nonallergic (negative) nuts. MethodsFamilies of children that had undergone an OFC for peanut or tree nuts at Sydney Children's Hospital were invited to participate. Consenting families were sent an online questionnaire. ResultsThe response rate to the questionnaire was 64%. More than 85% of respondents had introduced all or some of the negative nuts after the OFC and most had maintained at least some regular exposure in the child's diet at the time of the study. The age at diagnosis of the nut allergy and an awareness of the benefit of introducing foods after a negative OFC were significantly (P < .05) associated with introducing negative nuts. There was improved quality of life in those that introduced negative nuts. ConclusionMost families introduced or attempted to introduce negative nuts after a negative OFC. Educating families on the benefits of introducing foods after a negative OFC result is an important factor contributing to successful reintroduction.

The role of diagnostic tests and oral food challenge results to predict sesame allergy

BackgroundThe presence of sesame allergy and its importance are increasing. ObjectiveTo determine the results of sesame and tahini oral food challenges (OFCs) and whether sesame-specific immunoglobulin E and skin prick tests (SPTs) accurately predicted sesame allergy in children. MethodsPatients with suspected sesame allergy between June 1, 2018, and June 1, 2020, were examined. ResultsOf 92 patients (n = 65, 70.7% of the patients were boys) with a median age of 2 years (interquartile range, 1.2-3.8 years), 64 were reactive to tahini. Of 64 patients, 41 had a positive OFC result and 23 had a consistent history. Of 54 sesame OFCs, 10 patients had a positive outcome. Of 44 with a negative outcome of sesame OFC, 4 experienced allergic reactions with tahini at home and 22 patients had a positive result for tahini OFC. In multivariate logistic regression analysis, clinical reactivity of sesame (either a consistent history or a positive OFC) was positively associated with sesame SPT (odds ratio, 2.120; 95% confidence interval, 1.136-3.957; P = .01) and tahini SPT (odds ratio, 1.661; 95% confidence interval, 1.143-2.413; P = .008). Nevertheless, sesame-specific immunoglobulin E did not predict clinical reactivity. Tahini OFC outcomes were well predicted for both sesame and tahini SPTs (area under the curves of 0.937 and 0.896, respectively, P < .001 for both). A sesame SPT wheal size of 5.25 mm had 90.6% sensitivity, 82.1% specificity, and 5.1 positive likelihood ratio. For tahini SPT, the 6-mm threshold had 100% sensitivity, 82.1% specificity, and 5.6 positive likelihood ratio. ConclusionIn the OFC, tahini emerged as a more optimal diagnostic tool to avoid false negatives. Furthermore, both high sesame and tahini SPT levels individually can help predict the diagnosis of sesame allergy.

Clinical Manifestations of Pediatric Food Allergy: a Contemporary Review.

Food allergies (FAs) are an emerging health care issue, and a "second wave of the allergy epidemic" was named. There are extensive data that documented the prevalence rate as high as approximately 10%. FAs are immunological adverse reactions, including IgE-mediated mechanisms, cell-mediated mechanisms, or mixed IgE- and cell-mediated mechanisms. A diagnosis of FA is made by specific symptoms encounter with food, detailed past history, sensitization tests, and oral food challenges (OFCs) if necessary. The component-resolved diagnostics (CRD) test can distinguish true or cross-reaction. "Minimal elimination" from the results of CRD and OFC could avoid unnecessary food restriction. Strict food limitation is harsh and stressful on patients and their families. Children with FAs experience a higher rate of post-traumatic stress symptoms (PTSS) and bullying than others. In the last 20years, oral immunotherapy (OIT), sublingual immunotherapy (SLIT), and epicutaneous immunotherapy (EPIT) are treatment strategies. OIT and EPIT are the most two encouraging treatments for FA. This review aims to introduce FAs in diverse clinical disorders, new perspectives, and their practical implications in diagnosing and treating FA.

Detection of allergic reactions during oral food challenge using noninvasive urinary prostaglandin D2 metabolites

Oral food challenge (OFC) is a gold standard diagnostic method for food allergy (FA).1 Positive or negative OFC results are judged by an experienced physician based on objective allergic signs without reference to accurate biomarkers. Although tingling or itching in the mouth, which commonly first appears before patients develop anaphylaxis, is included as one of the allergic symptoms elicited by an immunoglobulin E (IgE)-mediated FA2 . However, subtle symptoms do not fulfill the diagnostic criteria of an OFC-positive FA. The biggest issue for OFC is that the assessment is not based on the objective biomarker and that the judgment is uneven among physicians. Moreover, various cofactors influence the outcomes of OFC (e.g., dose, infection, and psychological factors).

Legume and sesame oral food challenge outcomes.

Legume and sesame are emerging food allergens. The utility of specific immunoglobulin E (sIgE) testing to predict clinical reactivity to these allergens is not well described. To describe clinical outcomes and sIgE in sesame and legume oral food challenges (OFC). We performed a retrospective review of 74 legume and sesame OFCs between 2007 and 2017 at the Ann and Robert H. Lurie Children's Hospital of Chicago. Clinical data, OFC outcome, and sIgE to legume and sesame were collected. Receiver operating characteristic curves and logistic regression models that predicted OFC outcome were generated. Twenty-eight patients (median age, 6.15 years) passed legume OFC (84.9%), and 25 patients (median age, 5.91 years) passed sesame OFC (61.0%). The median sIgE to legume was 1.41 kUA/L and, to sesame, was 2.34 kUA/L. In patients with failed legume OFC, 60.0% had cutaneous symptoms, 20.0% had gastrointestinal symptoms, and 20.0% had anaphylaxis. Of these reactions, 80.0% were controlled with antihistamine alone and 20.0% required epinephrine. In patients for whom sesame OFC failed, 50.0% had cutaneous symptoms, 12.5% had gastrointestinal symptoms, and 37.50% had anaphylaxis. Of these reactions, 6.3% required epinephrine, 31.3% were controlled with diphenhydramine alone, and 63.50% required additional epinephrine or prednisone. Most OFCs to legumes were passed and reactions to failed legume OFCs were more likely to be nonsevere. Sesame OFC that failed was almost twice as likely compared with legume OFC that failed, and reactions to sesame OFC that failed were often more severe. Sesame sIgE did not correlate with OFC outcome.

Clinical Predictors and Outcomes of Oral Food Challenges Illustrate Differences Among Individual Tree Nuts

Although allergy to tree nuts is often considered a single entity, there is heterogeneity in patient reactivity and immune response to different tree nuts. We sought to characterize tree nut oral food challenges (OFCs) in a pediatric population performed at a single center over a 12-year period and determine differences in OFC outcome to different tree nuts. A retrospective chart review was conducted in patients (0-20 years) who completed an unblinded OFC to any tree nut from 2007 to 2019 at Lurie Chlildren's Hospital of Chicago. Differences among almond, cashew, hazelnut, and walnut challenges were compared, and probability curves were used to estimate positive predictive values (PPVs) of specific IgE at OFC. A total of 531 tree nut OFCs were included. The mean age at OFC was 7.77 years (standard deviation, 4.33). Overall, 74.0% of children passed clinically indicated OFCs. Of the 4 most commonly challenged tree nuts, almost all patients passed OFC to almond (97.3%) and hazelnut (87.9%). Pass rates were lower for cashew (65.3%) and walnut (57.0%), P < .0001. The odds of failure were 0.83 times lower for patients who were avoiding without a previous reaction compared with those who had previously reacted (P= .0025). The majority of patients pass low-risk almond and hazelnut OFCs. PPVs at the 50th percentile for walnut (2.84kU/L) and cashew (3.35 kU/L) were lower than those previous studies have suggested.

Factors associated with outcome of egg allergy 1 year after oral food challenge: A good baseline quality of life may be beneficial.

Safely liberalizing the diet to include an allergenic food may accelerate resolution of food allergy. The outcome of liberalization, however, varies among patients. We conducted a prospective observational study to identify factors associated with outcome for egg allergy 1year after oral food challenge (OFC). We enrolled children <72months old who had egg allergy and underwent OFC for determination of the safe intake quantity of egg allergen. Each child's baseline clinical background was recorded. Caregivers used the Food Allergy Quality of Life Questionnaire-Parent Form (FAQLQ-PF) to assess their children's QoL. Dietary advice based on the OFC result was provided to support safe egg consumption. At 1year after OFC, the quantity of egg each child safely consumed in daily life was surveyed. We classified the outcome as Successful (Group S) if the quantity increased during the 1year, or as Unsuccessful (Group U) if it did not. Factors associated with the outcome were investigated by multivariate logistic regression analysis. A total of 93 children were enrolled, and after 1year, 57 finished in Group S and 36 in Group U. The mean FAQLQ-PF score at baseline was significantly lower (ie, a better QoL) in Group S than in Group U. Multivariate logistic regression analysis identified a good QoL and absence of comorbid asthma or atopic dermatitis as factors predicting a favorable outcome. QoL may affect food allergy outcome. Intervention focusing on the QoL may promote outgrowing of food allergies.

Clinical predictors and outcomes of oral food challenges illustrate differences among individual tree nuts

Although allergy to tree nuts is often considered a single entity, there is heterogeneity in patient reactivity and immune response to different tree nuts. We sought to characterize tree nut oral food challenges (OFC) in a pediatric population performed at a single center over a 12-year period and determine differences in OFC outcome to different tree nuts.

Predicting Outcomes of Baked Egg and Baked Milk Oral Food Challenges Using a Ratio of Food-Specific IgE to Total IgE

Food-specific IgE (sIgE) and skin prick tests are used to risk-stratify patients for oral food challenges (OFCs). More accurate predictors are needed. Our objective was to evaluate the ratio of sIgE to total IgE (tIgE) (the “Ratio”) as a predictor of outcomes for OFCs to baked egg and baked milk and to determine if the Ratio better predicts the outcome of OFCs compared with sIgE alone. Data from all OFCs to baked (extensively-heated) egg and baked milk from January 2010 until January 2016 were reviewed for pre-challenge sIgE and tIgE, post-challenge outcome, and severity of reaction in failed challenges. The Ratio was calculated for egg white, ovomucoid, and milk and assessed as a predictor of OFC outcome with receiver operator characteristic (ROC) curves. The pre-challenge Ratios of egg white and milk were significantly higher in failed challenges as compared to passed challenges, 1.19% vs. 0.71% (p=0.02) for baked egg, and 3.68% vs. 0.75% (p=0.02) for baked milk. The Ratio for ovomucoid was not significantly higher in failed as compared to passed challenges for baked egg, 0.50% vs. 0.44%, (p=0.47). When assessing ROC curves, the Ratio did not perform significantly better than sIgE alone in predicting challenge outcome for egg white, 0.62 vs 0.68 (p=0.24), ovomucoid 0.54 vs. 0.58 (p=0.55), or milk 0.73 vs 0.69 (p=0.70). The Ratios for egg white and milk were predictive of outcomes of baked egg and baked milk challenges, respectively; however, the Ratio was not more predictive than sIgE alone.

Avoidance of Hen's Egg Based on IgE Levels Should Be Avoided for Children With Hen's Egg Allergy.

Background: Although hen's egg (HE) allergy was thought to be usually resolved by late childhood, majority of HE allergy patients with a high level of egg white (HEW)-specific IgE could not acquire tolerance for HE by age 8 years.Objective: The aim is to investigate whether the avoidance of HE until 6 years of age increased the risk of heated HE allergy at age 6 years.Methods: This was a retrospective case-control study. The HE tolerance children (n = 17) and children with low-dose HE reactor [a positive reaction to ≤ 4 g of heated HEW in oral food challenges (OFCs)] children (n = 26) were included based on the results of OFC at 6 years old. Multivariate logistic regression analysis was applied to examine the associations between HE avoidance until age 6 years and HE allergy status confirmed by OFC, adjusting the level of ovomucoid-specific IgE (OM-sIgE) during early infancy.Results: A lower proportion of strict avoidance of HE was observed in the HE tolerance group than in the low-dose HE reactor group (6 vs. 46%, p = 0.006). OM-sIgE levels in children younger than 2 years old were significantly higher in the low-dose HE reactor group than those in the HE tolerance group (median [interquartile], 26.7 UA/mL [11.9–53.4] vs. 7.9 UA/mL [0.35–23.4]; p =0.024). The avoidance of HE until 6 years of age increased the risk of heated HE allergy even after adjusting OM-sIgE levels.Conclusions: The long-term avoidance of HE from infancy increased the risk of heated HE allergy confirmed by OFC at age 6 years.

Specific IgE levels as an outcome predictor in egg-allergic children.

Diagnosis of immunoglobulin E (IgE)-mediated egg allergy is often based on both a compatible clinical history and either elevated IgE levels or a positive skin prick test. However, the gold standard is the oral food challenge (OFC). Previous studies have pointed to a correlation between IgE levels and OFC outcomes. This study aimed to determine the relationship between IgE levels and the outcome of OFC, seeking to establish cut-off OFC values that indicate a high likelihood of positive OFC results. A total of 198 patients who underwent OFC (and a serological IgE antibody assay within the three preceding months) were reviewed and divided by OFC type (i.e., baked, cooked, or raw egg). IgE-specific levels were assessed against the challenge outcome as well as cut-offs proposed by other authors. Receiver-operating characteristic (ROC) curve analysis yielded a potentially useful ovomucoid IgE-specific cutoff used in OFC with cooked egg and several egg white and ovalbumin IgE-specific cut-offs for OFC with raw egg. We found no significant relationship between other specific IgE concentrations and the challenge threshold level with baked eggs. IgE-specific concentrations are useful as predictors of OFC outcome and should be considered when selecting patients challenge testing with boiled or raw egg. However, patients should undergo OFC with baked egg regardless of IgE levels.

Agreement Between Predictive, Allergen-Specific IgE Values Assessed by ImmunoCAP and IMMULITE 2000 3gAllergy™ Assay Systems for Milk and Wheat Allergies.

PurposeImmunoCAP® (ImmunoCAP) and IMMULITE® 2000 3gAllergy™ (3gAllergy) systems are major quantitative allergen-specific immunoglobulin E (sIgE) assay methods. Due to the heterogeneous nature of allergenic extracts and differences in the assay format, quantitation of allergen-sIgEs is not expected to correlate well between different methods. However, we have recently reported good agreement between the methods in the diagnosis of egg allergy. This study aimed to determine and correlate the predictive values of sIgE by the two systems in the diagnosis of milk and wheat allergies.MethodsChildren who had undergone oral food challenge (OFC) for the diagnosis of milk and wheat allergies were enrolled. The OFCs were performed to diagnose either true allergy in the 1-year-old group (A) or tolerance in the 2- to 6-year-old group (B). Milk, casein and β-lactoglobulin, and wheat and ω-5 gliadin sIgE values were measured using the 2 systems. The predictive accuracy of each sIgE for the OFC outcome was assessed using receiver operating characteristic (ROC) curves. The probability of a positive OFC outcome was estimated by logistic regression analysis.ResultsA total of 395 patients were recruited from 7 primary care clinics and 19 hospitals in Japan. Milk and wheat OFCs were performed for 87 and 102 group A patients, and 124 and 82 group B patients, respectively. ROC analysis yielded similar areas under the curve for the 2 assays (0.7–0.9). The log-transformed sIgE data showed a strong linear correlation with the estimated probabilities (R > 0.9).ConclusionsThe 2 systems may be interchangeable for diagnosis of milk and wheat allergies in young children.

Skin prick testing a better predictor than blood testing for the diagnosis of peanut allergy in Chinese children.

Peanut allergy is common in Chinese children, yet the most predictive diagnostic cut-offs for skin prick test (SPT) and blood testing in this population are unclear. We aimed to determine the optimal cut-off values for whole-peanut SPT, specific IgE (sIgE) and component-resolved diagnostics (CRD) for Chinese children based on outcomes of open oral food challenges (OFC) to peanut. We recruited ethnic-Chinese patients 1-18 years old who were suspected of having peanut allergy based on a history of reactions after exposure or sensitization although peanut naïve. Considering the AUC value of 0.8, 80% power and 5% level of significance with two tails, 26 patients were needed. Sensitivities, specificities, positive and negative predictive values, and receiver operating characteristic curves (ROCs) and their area-under-curves (AUCs) for SPT, peanut sIgE, and CRD were compared. Thirty-one subjects participated. Only SPT reached statistical significance (AUC 0.91, p = 0.0001), but not the other tests. Seven retrospective data were added to optimize the power. SPT remained to be the best predictor, followed by Ara h 2 sIgE (AUC 0.72, p = 0.02). An SPT wheal size of 3 mm and Ara h 2 sIgE of 0.14 kU(A)/L yielded the highest Youden's index. The specificity of SPT and Ara h 2 sIgE reached 94% at 6 mm and 0.74 kU(A)/L, respectively. Comparisons of ROCs revealed that SPT was significantly better than Ara h 2 sIgE (p = 0.03) and whole-peanut sIgE (AUC 0.61, p = 0.26). In Chinese children, SPT appeared to be the best predictor for peanut allergy, followed by Ara h 2 sIgE.

Difficulties in interpretation of oral food challenge results.

Oral food challenge is the gold standard in diagnosing food allergies; however, many testing protocols are available. The present article illustrates the difficulties associated with interpreting oral challenge tests with the example of a six-year-old boy with allergy to hen’s eggs. The symptoms observed on the first day of challenge indicated a negative result; however, the consumption of the cumulative dose resulted in anaphylaxis. The interpretation of the oral food challenge can be complicated. The criteria used to determine a positive or negative result are sometimes ambiguous. An accurate interpretation of the results is key to determining correct management in children with food allergy.

Subjective oral symptoms are insufficient predictors of a positive oral food challenge.

Subjective oral symptoms, especially if recurrent, might lead to termination of an oral food challenge (OFC) for fear of a subsequent severe reaction. In a single-center retrospective cohort study, oral food challenges to milk, egg, peanut, sesame, or tree nuts performed between January 2016 and January 2018 in patients aged ≥3years, at the Institute of Allergy, Immunology and Pediatric Pulmonology in Shamir Medical Center, were analyzed. Subjective oral symptoms during the challenge were documented, and their association with the challenge outcome was examined. A total of 323 patients underwent 652 oral food challenges to the investigated foods (milk, 71; egg, 22; peanut, 48; sesame, 24; and tree nuts, 487). Subjective oral symptoms were experienced in 237 (36.3%) of all OFCs performed, and their rate was comparable across most foods tested. The rate of positive challenges was significantly higher when subjective oral symptoms were experienced during the challenge than when they were not (69.6% vs 30.4%, respectively, P<.001). However, the false-positive rate of such symptoms in predicting a positive food challenge was 30.3% for all foods; peanut, 40%; sesame, 27.3%; milk, 35.5%; egg, 33%; and tree nuts, 28.4%. Overall, subjective oral symptoms (SOS) provided sensitivity of 56.7, specificity 80.4, PPV 69.6, and NPV 69.0 for predicting OFC outcome. Importantly, reactions during positive challenges with and without subjective oral symptoms were comparable to severity. Continuing OFCs with subjective oral symptoms is recommended for it will prevent false-positive results in a third of cases without increasing patients' risk.

Two Different Composite Markers Predict Severity and Threshold Dose in Peanut Allergy

Safe and cost-effective biological surrogate markers to evaluate the severity and threshold dose of peanut allergy (PA) reactions during an oral food challenge (OFC) are lacking. To evaluate biological markers associated with the severity and threshold dose of an allergic reaction during an OFC in a population of children with PA. Demographic and biological parameters of children with peanut OFC and basophil activation test (BAT) results were collected. Patients were stratified into 2 severity groups (mild-to-moderate and severe) and 2 cumulative threshold dose groups: low (LCTG) ≤100 mg crushed peanut and high >100 mg. Among the 68 children included, there was a 96% concordance between the OFC and BAT result for the diagnosis of PA. Of the 56 children with a positive OFC and BAT to peanut (median age: 8.8 years), the severity of an allergic reaction and the cumulative threshold dose were not correlated (P= .24). Higher Ara h 2-specific IgE and FcεRI-positive control values were both associated with severe reactions to peanut. Combining these 2 markers led to a 92% sensitivity (84%-97%) and an 82% specificity (71%-89%) for severe reactions in all subjects. For children in the LCTG, a 4-variable composite marker, including age, normalized basophil sensitivity (EC50), and FcεRI- and fMLP-positive control values, resulted in a 97% sensitivity (89%-99%) and 61% specificity (49%-71%). Distinct composite markers including BAT allergen-specific and non-allergen-specific parameters appear to be associated with severity and cumulative threshold dose in children with PA.

Adverse reactions to food additives in children: A retrospective study and a prospective survey

BackgroundAllergic reactions to food additives are often suspected by families. The aim of this study was to describe oral food challenge (OFC) outcomes in a pediatric cohort with a suspected diagnosis of allergy to food additives (food dyes or sodium benzoate). MethodsAll patients who underwent an open OFC to carmine red, cochineal red, erythrosine, patent blue V, tartrazine, yellow sunset S, and/or sodium benzoate were included. A survey was sent to families after testing to evaluate whether the OFC results had altered feeding behaviors with food additives. ResultsTwenty-three patients were included. The main suspected food was candy (n=11/23; 48%). Only one OFC out of 45 was formally positive for the carmine and cochineal red. Subsequently, most OFCs were negative (44/45; 97.8%). Despite the negativity of the challenge, four families out of 14 reported occurrences of supposed allergic reactions to food additives and six out of 15 continued to completely avoid the additive of concern in their children's diet. ConclusionsAllergies to food additives remain rare. Even if an IgE-mediated allergy was excluded with a negative OFC, families remained suspicious about ready-made products. Health professionals and parents should be reassured about the low risk of food dye intolerance or allergies.