Risk prediction of severe reaction to oral challenge test of cow's milk

Timing of initial symptom onset during milk and wheat challenges: A retrospective study

BACKGROUND

Allergic reactions to milk appear sooner than those to hen's eggs, irrespective of the total dose of the oral food challenges (OFCs) and type of matrices. The reported median times for the first symptom occurrence are 20-30 min with milk and 50-60 min with eggs. However, allergic reactions due to wheat have not yet been fully investigated.

METHODS

This study retrospectively collected data from OFC for milk and wheat conducted at Sagamihara National Hospital and Sendai Medical Center from 2009 to 2023. The time from the start of the OFC to the onset of symptoms was compared between children with cow's milk and wheat allergy.

RESULTS

Twenty-five and 13 children reacted to single-dose OFCs with milk products equivalent to 25 mL of raw cow's milk or 15 g of udon noodles, respectively. The median ages of patients with positive challenges were 1.4 and 2.8 years for milk and wheat, respectively, and the median times for the first symptom occurrence were 20 min and 53 min, respectively (p = .006).

CONCLUSION

This multicenter study was the first to examine the time of symptom appearance during single-medium-dose milk and wheat challenges. Allergic reactions to wheat appear later than those for milk during OFC. For multiadministration OFC for wheat, the dosing interval should be longer than 60 min. Our findings can help improve the safety of OFCs.

Transepidermal water loss rises before food anaphylaxis and predicts food challenge outcomes

BACKGROUNDFood allergy (FA) is a growing health problem requiring physiologic confirmation via the oral food challenge (OFC). Many OFCs result in clinical anaphylaxis, causing discomfort and risk while limiting OFC utility. Transepidermal water loss (TEWL) measurement provides a potential solution to detect food anaphylaxis in real time prior to clinical symptoms. We evaluated whether TEWL changes during an OFC could predict anaphylaxis onset.METHODSPhysicians and nurses blinded to the TEWL results conducted and adjudicated the results of all 209 OFCs in this study. A study coordinator measured TEWL throughout the OFC and had no input on the OFC conduct. TEWL was measured 2 ways in 2 separate groups. First, TEWL was measured using static, discrete measurements. Second, TEWL was measured using continuous monitoring. Participants who consented provided blood samples before and after the OFCs for biomarker analyses.RESULTSTEWL rose significantly (2.93 g/m2/h) during reactions and did not rise during nonreacting OFCs (-1.00 g/m2/h). Systemic increases in tryptase and IL-3 were also detected during reactions, providing supporting biochemical evidence of anaphylaxis. The TEWL rise occurred 48 minutes earlier than clinically evident anaphylaxis. Continuous monitoring detected a significant rise in TEWL that presaged positive OFCs, but no rise was seen in the OFCs that resulted in no reaction, providing high predictive specificity (96%) for anaphylaxis against nonreactions 38 minutes prior to anaphylaxis onset.CONCLUSIONSDuring OFCs, a TEWL rise anticipated a positive clinical challenge. TEWL presents a monitoring modality that may predict food anaphylaxis and facilitate improvements in OFC safety and tolerability.

IgE-mediated cow's milk allergy in Brazilian children: Outcomes of oral food challenge

Background

Oral food challenge (OFC) is useful for diagnosing food allergies and assessing tolerance, but severe reactions may occur during the procedure.

Objective

To characterize the frequency and severity of reactions during cow's milk (CM) OFCs.

Methods

A cross-sectional study was conducted to analyze the outcome of cow's milk oral food challenges (CMOFCs) performed to confirm IgE-mediated CM allergy or to assess food tolerance. CM was given first as baked milk (BM), followed by whole CM if there was no prior reaction to BM. An OFC was considered positive if IgE-mediated symptoms developed up to 2 h after ingestion. Symptoms were described and variables including age at OFC, prior anaphylaxis, other atopic diseases, and skin test results were compared according to the OFC outcomes.

Results

A total of 266 CMOFCs were performed, including 159 patients with a median age of 6.3 years old. One hundred thirty-six tests were positive and 62 resulted in anaphylaxis. Thirty-nine anaphylactic reactions were observed up to 30 min after the first dose. Severe anaphylaxis (cardiovascular and/or neurological involvement) was reported in 5 tests. A second dose of epinephrine was required in 3 tests, and 1 presented a biphasic response. Younger patients had a higher risk of anaphylaxis during baked milk oral food challenge (BMOFC) (p = 0.009). The frequency of anaphylaxis was higher in patients submitted to BM (p = 0.009).

Conclusions

Anaphylaxis is a known complication of CMOFCs even when there is no prior anaphylaxis or when conducted with baked products. This study reinforces the importance of conducting OFC in appropriate settings with a well-trained team.

The Heterogeneity of Ovomucoid-Specific IgE Idiotype Is Associated With Egg Allergy Symptom Severity

Immunoglobulin E (IgE)-mediated egg allergy presents as one of the most common food allergies. The level of specific IgE (sIgE) antibody is widely used as an important in vitro diagnostic indicator. However, sIgE antibody levels are often inconsistent with the clinical manifestations of patients. The heterogeneity of egg-specific IgE idiotypes (sIgE-IDs) may help reflect clinical egg allergy severity. Eight peptides were synthesized, corresponding to the linear epitopes of ovomucoid (OVM). The sIgE-IDs of egg-allergic patients were detected by enzyme-linked immunosorbent assay. Fresh peripheral blood was collected from patients with different heterogeneity strength of sIgE-ID, and egg extract was used as a stimulus to the basophil activation test (BAT). RBL-2H3 cells were sensitized with serum with different strength of sIgE-ID heterogeneity and the release rate of β-hexosaminidase was calculated. Among 75 patients with egg allergy, 24% had sIgE for all epitopes and 85% had sIgE for at least one epitope. Analysis of individual patients revealed differences in epitope recognition patterns among the patients, that is, heterogeneity in sIgE-ID. More importantly, the number of IgE-positive peptides had a strong correlation with allergic symptoms in egg-allergic patients (r = 0.706). BAT and RBL-2H3 cell degranulation confirmed that higher sIgE-ID heterogeneity strength was more effective in inducing effector cell responses. Our results suggest that the greater the heterogeneity strength of OVM-sIgE-ID, the more severe the allergic symptoms.

Cow's milk allergy

PURPOSE OF REVIEW

To highlight the most recent insights on cow's milk allergy (CMA), its treatment, and management.

RECENT FINDINGS

CMA is one of the most common food allergies among children. Burdened by the risk for fatal reaction, CMA may imply also a severe impairment of health-related quality of life at individual and family level as well as well as individual and societal costs. The updated Diagnosis and Rationale for Action against Cow's Milk Allergy series is going to provide a series of manuscripts that will offer a comprehensive state-of-the-art specifically on CMA, including international evidence-based recommendations. The current results from randomized clinical trials highlight that oral immunotherapy may be effective by itself in providing desensitization. Preliminary data suggest that biologicals such as omalizumab may be able to increase the threshold of reactivity to milk or several foods (if multiple food allergies) without requiring allergen exposure. Breastfeeding is the first choice for infants with CMA. Extensively hydrolyzed formula and amino-acid formula are valid alternatives and may be particularly helpful when eliminating multiple foods, with severe complex gastrointestinal food allergies, eosinophilic esophagitis, severe eczema, or symptoms while exclusively breastfeeding. Heed is needed to ensure the formula is nutritionally sufficient. Due to a high degree of cross-reactivity with cow's milk proteins and risk for allergic reactions, goats' milk or other mammals' milk should not be used.

SUMMARY

The adoption and implementation of evidence-based recommendations may guide a proper diagnostics and management and awaited advances in knowledge will allow the development of a personalized treatment tailored on the specific CMA patient's profile.

World Allergy Organization (WAO) Diagnosis and Rationale for Action against Cow's Milk Allergy (DRACMA) Guidelines update – I – Plan and definitions

Since the World Allergy Organization (WAO) Diagnosis and Rationale against Cow's Milk Allergy (DRACMA) Guidelines were published 10 years ago, new evidence has accumulated about the diagnosis, therapy, and specific immunotherapy for cow's milk allergy (CMA). For this reason, WAO has felt the need to update the guidelines.

We introduce here this update. The new DRACMA guidelines aim to comprehensively address the guidance on diagnosis and therapy of both IgE non-IgE-mediated forms of cow's milk allergy in children and adults. They will be divided into 18 chapters, each of which will be dedicated to an aspect. The focus will be on the meta-analyzes and recommendations that will be expressed for the 3 most relevant clinical aspects: (a) the diagnostic identification of the condition; (b) the choice of the replacement formula in case of CMA in infancy when the mother is not able to breastfeed, and (c) the use of specific immunotherapy for cow's milk protein allergy.

Emerging Food Allergy Biomarkers

The management of food allergy is complicated by the lack of highly predictive biomarkers for diagnosis and prediction of disease course. The measurement of food-specific IgE is a useful tool together with clinical history but is an imprecise predictor of clinical reactivity. The gold standard for diagnosis and clinical research is a double-blind placebo-controlled food challenge. Improvement in our understanding of immune mechanisms of disease, development of high-throughput technologies, and advances in bioinformatics have yielded a number of promising new biomarkers of food allergy. In this review, we will discuss advances in immunoglobulin measurements, the utility of the basophil activation test, T-cell profiling, and the use of -omic technologies (transcriptome, epigenome, microbiome, and metabolome) as biomarker tools in food allergy.

Asthma and anaphylaxis

PURPOSE OF REVIEW

Both asthma and anaphylaxis are recognized noncommunicable hypersensitivity conditions, which should be correctly diagnosed and treated/controlled in order to decrease avoidable deaths. Nevertheless, their association is not completely clear. We here propose to review the current and new evidence-based data of asthma and anaphylaxis in the view of the new knowledge in the field that can support the quality practice and empower allergists and health professionals in treating symptoms and preventing death.

RECENT FINDINGS

Hypersensitivity life-threatening conditions, such as anaphylaxis and asthma can coexist, mimic or worse each other. Asthma itself is not a strong predictor of more severe anaphylaxis. However, poor asthma control associated with more severe anaphylaxis reactions in all ages. In children, asthma is associated with the severity and recurrences of anaphylactic reactions.

SUMMARY

Although recent data point for the association between asthma and anaphylaxis, we still do not have harmonized evidence to confirm if we are dealing with two independent comorbidities one worsening each other. However, as far as this review is covering two relevant public health problems in the field of allergy, it is mandatory put in place decisions supporting recommendations to better manage the affected patients and reduce the risk.General strategies should include regular notification of this association, optimization of the classification and coding for anaphylaxis and asthma (new ICD 11 allergy codes) in order to harmonize epidemiological stratified data, early diagnosis of asthma in childhood, regular investigation of asthma in cases of anaphylaxis and optimization of the asthma control and lung function for all patients with indication to provocation tests, desensitization or allergen immunotherapy regardless to the trigger. Implementation of these strategies will involve national and international support for ongoing efforts in relationship with networks of centres of excellence to provide personalized management for the most at-risk patients and prevent death.