Skin prick test and specific serum IgE in the diagnostic evaluation of suspected cow's milk and hen's egg allergy in children: does one replace the other?

An ESPGHAN Position Paper on the Diagnosis, Management, and Prevention of Cow's Milk Allergy

A previous guideline on cow's milk allergy (CMA) developed by the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) was published in 2012. This position paper provides an update on the diagnosis, treatment, and prevention of CMA with focus on gastrointestinal manifestations. All systematic reviews and meta-analyses regarding prevalence, pathophysiology, symptoms, and diagnosis of CMA published after the previous ESPGHAN document were considered. Medline was searched from inception until May 2022 for topics that were not covered in the previous document. After reaching consensus on the manuscript, statements were formulated and voted on each of them with a score between 0 and 9. A score of ≥6 was arbitrarily considered as agreement. Available evidence on the role of dietary practice in the prevention, diagnosis, and management of CMA was updated and recommendations formulated. CMA in exclusively breastfed infants exists, but is uncommon and suffers from over-diagnosis. CMA is also over-diagnosed in formula and mixed fed infants. Changes in stool characteristics, feeding aversion, or occasional spots of blood in stool are common and in general should not be considered as diagnostic of CMA, irrespective of preceding consumption of cow's milk. Over-diagnosis of CMA occurs much more frequently than under-diagnosis; both have potentially harmful consequences. Therefore, the necessity of a challenge test after a short diagnostic elimination diet of 2-4 weeks is recommended as the cornerstone of the diagnosis. This position paper contains sections on nutrition, growth, cost, and quality of life.

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

Comparison of commercial allergen extract with various milk products of skin prick tests in diagnosing cow's milk protein allergy

Introduction: In this study, we aimed to solve the incompatibilities between the skin prick test (SPT) result and the clinical picture encountered among patients. Thus, we used various milk products (raw, ultrahigh temperature [UHT], and pasteurized cow's milk) with commercial milk allergen extract in patients we think may have cow's milk protein allergy (CMPA) and made a comparison among the milk types. Methods: This study was conducted retrospectively between February 1, 2019, to June 1, 2019, at a pediatric allergy polyclinic of the university training/research hospital. A pair of 79 individuals, as control and patient groups, ages between 1 month and 21 years who were presented with a suspicion of CMPA and defined with SPT and/or allergen-specific immunoglobulin E (IgE) levels were included in the study. Allergen-specific IgE tests (specific IgE cow's milk, β-lactoglobulin, α-lactalbumin, casein) were evaluated. SPT was performed with fresh/raw, UHT, and pasteurized (daily) cow's milk besides the standard used commercial extract. Results: In the group included in the study and defined as IgE-mediated CMPA, 52.9% of the 79 patients were boys (n = 46), 47.1% were girls (n = 33), and the median age was 6 months (5.0-8.0 months). In the group of specific IgE cow's milk reaction that was sought, frequency and wheal (induration) size of SPT reaction to fresh/raw milk was also found to be statistically significant between positive- and negative-reaction groups, not detected against other milk products. The area under the curve for the diagnostic value of fresh milk was 93.1%. For the cutoff value of 2.50 mm, 88.1% sensitivity and 90.8% specificity were determined. In the group of specific IgE β-lactoglobulin reaction searched, there was a statistically significant difference in the frequency of SPT positivity and wheal size against UHT, fresh, and daily/pasteurized milk between positive and negative reaction groups. When the correlations of the mean induration axis in the tests were examined, it was found that, among raw milk, daily milk, cow's milk allergen extract, and UHT milk, a strong positive correlation was also statistically significant. Conclusion: The positivity that could not be detected with SPT when using allergen extract in a patient with positive specific IgE cow's milk result in the clinic can be detected with SPT made with fresh (raw) milk, which can be an alternative. In addition, specific IgE β-lactoglobulin seems to be the most compatible with the SPT wheal size (induration) of other milk types rather than extract. Comparative studies of SPT allergen extracts and various milk types used in the diagnosis of CMPA are very scarce in the literature, and more studies are needed on this subject.

[Food Allergy in Childhood]

Food Allergy in Childhood Abstract. Food allergies in childhood are on the rise and are therefore a topical issue in practice. In this article, we describe the most common allergens and risk factors for the development of a food allergy. The classification of IgE- and non-IgE-mediated food allergies and their respective clinical manifestations are highlighted. The importance of a careful diagnosis with targeted history taking and allergy testing and finally the performance of oral provocation for the diagnosis will be presented in a practical manner. We will discuss the care of families of children with food allergies, whereby support through nutritional counselling as well as equipping families with an emergency kit, including appropriate instructions for use, are important. Finally, the latest therapeutic approaches of specific immunotherapy, which aims to induce tolerance, are presented and the prognosis of food allergies is discussed.

[Pitfalls in the diagnostics of food allergies in children and adolescents]

For the diagnostics of food allergies several points need to be considered. Firstly, it is important to recognize the various clinical pictures that can be caused by a food allergy. The assignment to a disease decides which further examinations are necessary and reasonable. In immunoglobulin (Ig) E‑mediated allergies, the detection of sensitization by determining the specific IgE or the prick test in addition to the medical history is an important mainstay of the diagnostics. Crucial is the fact that the detection of a sensitization against an extract from an allergen source only rarely implies an actual allergy. The majority of positive findings are not clinically relevant. The modern procedure of component-resolved allergy diagnostics improves the significance. Nevertheless, the diagnosis can often only be achieved by oral provocation tests. This article points out possible difficulties with the interpretation of the findings.

Design, quality, safety and efficacy of extensively hydrolyzed formula for management of cow's milk protein allergy: What are the challenges?

Cow's milk protein allergy (CMPA) is one of the most common food allergies in infancy. Clinical food allergy guidelines recommend an extensively hydrolyzed formula (EHF) as the first-line treatment in nonbreastfed infants with CMPA. Designing and commercializing EHF poses both technical and regulatory challenges. Each manufacturing step, from sourcing of raw materials to release of the final product, needs to be managed in accordance with comprehensive quality systems. To avoid cross-contamination via externally sourced ingredients, suppliers should be carefully selected based on quality requirements. Strict zoning of the manufacturing areas according to contamination risk and air flow control are effective strategies to prevent accidental allergen contamination. Furthermore, dedicated manufacturing lines for hypoallergenic products are used to prevent potential cross-contamination from other products produced on the same line. The enzymatic hydrolysis, heat treatment and ultrafiltration used are specific to each manufacturer. Consequently, EHF are a heterogenous group of products with differences in the molecular weight profile of peptides, content of residual immunogenic cow's milk allergens, and residual in-vitro allergenicity. These differences are likely to affect clinical efficacy and safety. As not all commercialized EHF products have undergone formal testing in the laboratory and clinical trials, there is a need to develop guidelines for minimum technical and regulatory requirements for EHF products, including validated assays for ongoing quality control. Clinical trials assessing new EHF products for their hypoallergenicity and ability to support normal growth remain the definitive proof of efficacy and safety in infants and young children with CMPA.

Association of early viral lower respiratory infections and subsequent development of atopy, a systematic review and meta-analysis of cohort studies

INTRODUCTION

Existing evidence on the relationship between childhood lower respiratory tract infections (LRTI) and the subsequent atopy development is controversial. We aimed to investigate an association between viral LRTI at <5 years and the development of atopy at > 2 years.

METHODS

We conducted a search at Embase, Pubmed, Web of Science, and Global Index Medicus. We collected data from the included articles. We estimated the odds ratio and the 95% confidence intervals with a random effect model. We determined factors associated with atopy development after childhood LRTI using univariate and multivariate meta-regression analyses. We recorded this systematic review at PROSPERO with the number CRD42018116955.

RESULTS

We included 24 studies. There was no relationship between viral LRTI at <5 years and skin prick test-diagnosed-atopy (OR = 1.2, [95% CI = 0.7-2.0]), unknown diagnosed-atopy (OR = 0.7, [95% CI = 0.4-1.3]), atopic dermatitis (OR = 1.2, [95% CI = 0.9-1.6]), hyperreactivity to pollen (OR = 0.8, [95% CI = 0.3-2.7]), food (OR = 0.8, [95% CI = 0.3-2.5]), or house dust mite (OR = 1.1, [95% CI = 0.6-2.2]). Although not confirmed in all studies with a symmetric distribution of the 23 confounding factors investigated, the overall analyses showed that there was a relationship between childhood viral LRTI at < 5 years and serum test diagnosed-atopy (OR = 2.0, [95% CI = 1.0-4.1]), allergic rhinoconjunctivitis (OR = 1.7, [95% CI = 1.1-2.9]), hyperreactivity diagnosed by serum tests with food (OR = 5.3, [1.7-16.7]) or inhaled allergens (OR = 4.2, [95% CI = 2.1-8.5]), or furred animals (OR = 0.6, [95% CI = 0.5-0.9]).

CONCLUSION

These results suggest that there is no association between viral LRTI at < 5 years and the majority of categories of atopy studied during this work. These results, however, are not confirmed for the remaining categories of atopy and more particularly those diagnosed by serum tests. There is a real need to develop more accurate atopy diagnostic tools.

High prevalence of eczema among preschool children related to home renovation in China: A multi-city-based cross-sectional study

We surveyed 40 010 three- to six-year-old children in seven Chinese cities (Beijing, Taiyuan, Urumqi, Shanghai, Nanjing, Changsha, and Chongqing) during 2010-2012 so as to investigate possible links between home renovation and childhood eczema. Their parents responded to questions on home renovation and childhood eczema. Multivariate and two-level (city-child) logistic regression analyses yielding odds ratios with 95% confidence intervals were performed. Sensitivity analyses stratifying data for region, climate, and income level were also performed. The prevalences of childhood eczema in children with different floor and wall covering materials were significantly different and were significantly higher with home renovation during early lifetime. Exposure to synthetic materials significantly increased the risk of childhood eczema by 20%-25%. The risks (AOR, 95% CI) of current eczema among children in families with solid wood flooring and oil paint wall covering were 1.25 (1.04-1.49) and 1.35 (1.14-1.60), respectively. Home renovation during pregnancy was related to children's lifetime and current eczema.

Can evaluation of specific immunoglobulin E serum concentrations of antibodies to aeroallergens in atopic dermatitis patients replace skin prick tests method in clinical practice?

Introduction

Positive skin prick tests (SPT) results with protein allergens are the minor Hanifin and Rajka's atopic dermatitis (AD) criterion. In adults, they mainly concern aeroallergens. The inflammation of skin often prevents SPT, but does not exclude the assessment of serous specific immunoglobulin E (sIgE) concentrations.

Aim

To assess usefulness of testing AD patients to aeroallergens with SPT and sIgE concentrations, and the correlation of these results and the clinical AD course.

Material and methods

In 286 AD patients, total IgE and sIgE (14 aeroallergens) were measured. SPTs were performed with 17 aeroallergens. The AD severity was determined depending on the concurrent co-existence of asthma, allergic rhinitis, extensive skin flares and severe itching.

Results

59.1% and 66.1% of patients have had positive results of sIgE and SPT, respectively (p > 0.05). The concentration of total IgE has positively correlated with the number of positive sIgE results (rho = 0.588, p < 0.001) and their intensity (rho = 0.592, p < 0.001). Among the patients with at least one high positive sIgE score, severe AD patients have been dominant (59.8% vs. 40.2%, p < 0.04). Among the patients with positive results without any high scores, the percentages are 21.6 and 78.4, respectively (p < 0.001).

Conclusions

The compatibility of SPT results and IgE concentrations indicates that the two methods equally assess aeroallergy in AD patients. The assessment of sIgE concentrations is especially advisable in patients with an elevated total IgE level. The obtained results may suggest that presence of a high specific IgE level of antibodies to aeroallergens may be the factor predicting a severe clinical AD course.

Analysis of Allergen-Specific T Cell and IgE Reactivity to Different Preparations of Cow's Milk-Containing Food Extracts

BACKGROUND

cow's milk allergy (CM) is among the most common food allergies in young children and is often outgrown by adulthood. Prior to developing a tolerance to CM, a majority of CM-allergic children may tolerate extensively-heated CM. This study aims to characterize the IgE- and T cell-reactivity to unheated CM and the progressively more heated CM-containing foods.

METHODS

CM-containing food extracts from muffin, baked cheese, custard and raw, pasteurized CM commercial extract were tested for skin prick test reactivity, IgE binding and T cell reactivity as assessed by IL-5 and IFNγ production.

RESULTS

the skin prick test (SPT) reactivity was significantly decreased to muffin extract compared to raw, pasteurized CM. Both IgE- and T-cell reactivity were readily detectable against food extracts from all forms of CM. Western blot analysis of IgE reactivity revealed variability between extracts that was protein-specific. T cell-reactivity was detected against all four extracts with no significant difference in IL-5 or IFNγ production between them.

CONCLUSION

our data indicate that despite reduced clinical reactivity, extracts from heated CM-containing foods retain immunogenicity when tested in vitro, particularly at the T cell level.

Concordance of skin prick test and serum-specific IgE to locally produced component-resolved diagnostics for cockroach allergy

BACKGROUND

Diagnosis of Periplaneta americana (American cockroach, ACR) allergy is commonly performed based on clinical history and skin prick test (SPT) or specific serum IgE (sIgE) measurement. The concordance of the findings with the SPT and sIgE results has never been investigated.

OBJECTIVE

To compare the results of SPT with commercial ACR-extract (C-ACE) and sIgE measurement, using commercial kit and in-house enzyme-linked immunosorbent assay (ELISA) to the locally produced ACR extract (L-ACE) and native Per a 1, Per a 5, Per a 7, and Per a 9.

METHODS

Sera from 66 individuals clinically diagnosed with chronic allergic rhinitis were included; 46 were positive SPT to C-ACE, and 20 were negative. Specific serum IgE levels were established by using a commercial test kit (ImmunoCap) and an in-house IgE-ELISA RESULTS: The percentage the C-ACE SPT-positive cases that were positive by the ImmunoCap-sIgE was 32.6%, indicating low concordance of the 2 assays. With the in-house ELISA, Per a 9 gave the highest sensitivity (98.00%), positive predictive value (PPV; 95.74%), and negative predictive value (NPV; 94.74%) of the sIgE quantification. The correlation coefficients (R) of the L-ACE-SPT and sIgE to L-ACE, Per a 1, Per a 5, Per a 7, and Per a 9 and ImmunoCap sIgE were 0.133, 0.278, 0.419, 0.280, and 0.432, and 0.256, respectively.

CONCLUSION

Skin prick test and sIgE measurement using commercial reagents have low concordance. Data of this study showed that sIgE to the native Per a 9 should be considered as an adjunct to the clinical history in diagnosis of ACR sensitization/allergy, particularly when the SPT and the nasal challenge, which is the gold standard method, cannot be performed.

ImmunoCAP® ISAC and Microtest for multiplex allergen testing in people with difficult to manage allergic disease: a systematic review and cost analysis

BACKGROUND

Allergy is a form of immune-mediated exaggerated sensitivity (hypersensitivity) to a substance that is either inhaled, swallowed, injected or comes into contact with the skin. Foreign substances that provoke allergies are called allergens. It has been claimed that multiplex allergen testing may help in diagnosing the cause of symptoms in patients with an unclear cause of allergy or who are allergic to more than one substance.

OBJECTIVES

To evaluate multiplex allergen testing [devices that can measure the presence of multiple immunoglobulin E (IgE) antibodies in a patient's blood at the same time], by assessing (1) clinical effectiveness (allergy symptoms, incidence of acute exacerbations, mortality, adverse events of testing and treatment, health-care presentations or admissions, health-related quality of life); (2) effects on treatment (diet, immunotherapy medications, other potential testing); (3) any additional diagnostic information provided by multiplex allergen testing; and (4) cost-effectiveness (cost of different assessment strategies).

METHODS

Fifteen databases were searched from 2005 to April 2015, including MEDLINE (via OvidSp), MEDLINE In-Process Citations, MEDLINE Daily Update, PubMed (National Library of Medicine), EMBASE, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE), Health Technology Assessment (HTA) database, Science Citation Index (SCI), Conference Proceedings Citation Index-Science (CPCI-S), BIOSIS Previews, Latin American and Caribbean Health Sciences Literature (LILACS), National Institute for Health Research (NIHR) HTA programme, and the US Food and Drug Administration (FDA); supplementary searches of conference proceedings and trials registries were performed. Review methods followed published guidance from the Cochrane Collaboration and the Centre for Reviews and Dissemination, University of York, UK. The methodological quality of included studies was assessed using appropriate published tools or a review-specific tool designed by the project team. Studies were summarised in a narrative synthesis. Owing to a lack of data on the clinical effectiveness of multiplex allergen testing, no long-term cost-effectiveness model was developed. A conceptual model structure was developed and cost analyses were performed to examine the short-term costs of various possible diagnostic pathways.

RESULTS

Fifteen studies were included in the review. The very limited available data indicated that the addition of multiplex allergen testing [ImmunoCAP(®) Immuno Solid-phase Allergen Chip (ISAC), Thermo Fisher Scientific/Phadia AB, Uppsala, Sweden] to standard diagnostic work-up can change the clinicians' views on the diagnosis, management and treatment of patients. There was some indication that the use of ImmunoCAP ISAC testing may be useful to guide decisions on the discontinuation of restrictive diets, the content of allergen-specific immunotherapy (SIT) prescriptions, and whether or not patients should receive SIT. However, none of the studies that we identified reported any information on clinical outcomes subsequent to changes in treatment or management. There was some evidence that ImmunoCAP ISAC may be useful for discriminating allergens that are structurally similar and are recognised by the same IgE antibody (cross-immunoreactive). No data were available for Microtest (Microtest Matrices Ltd, London, UK). Detailed cost analyses suggested that multiplex allergen testing would have to result in a substantial reduction of the proportions of patients receiving single IgE testing and oral food challenge tests in order to be cost-saving in the short term.

CONCLUSIONS

No recommendations for service provision can be made based on the analyses included in this report. It is suggested that a consensus-based protocol for the use of multiplex allergen testing be developed. The clinical effectiveness and cost-effectiveness of the proposed protocol should then be assessed by comparing long-term clinical and quality of life outcomes and resource use in patients managed using the protocol with those managed using a standard diagnostic pathway.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015019739.

FUNDING

This project was a Diagnostic Assessment Report commissioned by the NIHR HTA programme on behalf of the National Institute for Health and Care Excellence.

[Food allergy in childhood]

IgE-mediated immediate type reactions are the most common form of food allergy in childhood. Primary (often in early childhood) and secondary (often pollen-associated) allergies can be distinguished by their level of severity. Hen's egg, cow's milk and peanut are the most common elicitors of primary food allergy. Tolerance development in hen's egg and cow's milk allergy happens frequently whereas peanut allergy tends toward a lifelong disease. For the diagnostic patient history, detection of sensitization and (in many cases) oral food challenges are necessary. Especially in peanut and hazelnut allergy component-resolves diagnostic (measurement of specific IgE to individual allergens, e. g. Ara h 2) seem to be helpful. In regard to therapy elimination diet is still the only approved approach. Patient education through dieticians is extremely helpful in this regard. Patients at risk for anaphylactic reactions need to carry emergency medications including an adrenaline auto-injector. Instruction on the usage of the adrenaline auto-injector should take place and a written management plan handed to the patient. Moreover, patients or caregivers should be encouraged to attending a structured educational intervention on knowledge and emergency management. In parallel, causal therapeutic options such as oral, sublingual or epicutaneous immunotherapies are currently under development. In regard to prevention of food allergy current guidelines no longer advise to avoid highly allergenic foods. Current intervention studies are investigating wether early introduction of highly allergic foods is effective and safe to prevent food allergy. It was recently shown that peanut introduction between 4 and 11  months of age in infants with severe atopic dermatitis and/or hen's egg allergy (if they are not already peanut allergic) prevents peanut allergy in a country with high prevalence.

Identification and characterization of ovary development-related protein EJO1 (Eri s 2) from the ovary of Eriocheir sinensis as a new food allergen

SCOPE

Crab is a major source of shellfish allergens. Most studies have focused on allergens in crab muscle (CM) rather than on allergens in crab ovary (CO). This study aimed to identify potential allergens in CO from Eriocheir sinensis.

METHODS AND RESULTS

Dot blot and immunoblotting results revealed the differential reactivity of CM and CO extracts to positive sera from patients allergic to crabs. Four CO proteins showed good specific IgE-binding activities in 2-DE/immunoblotting analysis; mass spectrometry identified the proteins as hemocyanin, vitellogenin, ovary development-related protein EJO1and EJO2. The recently identified allergen EJO1 is named 'Eri s 2' in the World Health Organization and International Union of Immunological Societies (WHO/IUIS) allergen nomenclature database. Recombinant Eri s 2 exhibited good reactivity to positive sera, and pre-incubation with recombinant Eri s 2 abrogated the reactivity of positive sera from two patients to CO in a dose-dependent manner. Moreover, co-incubation of recombinant Eri s 2 with patient basophils dose-dependently promoted basophil activation, confirming the biological activity of Eri s 2.

CONCLUSION

CO tissue is an important allergen source, and Eri s 2 is a new crab allergen. This study provides insights that will be useful for component-resolved diagnostics for crab allergy.

Food Allergy in childhood: phenotypes, prevention and treatment

The prevalence of food allergy in childhood increased in the last decades, especially in Westernized countries where this phenomenon has been indicated as a second wave of the allergic epidemic. In parallel, scientific interest also increased with the effort to explain the reasons of this sudden rise and to identify potential protective and risk factors. A great attention has been focused on early exposures to allergenic foods, as well as on other nutritional factors or supplements that may influence the immune system in a positive direction. Both interventions on maternal diet before birth or during breastfeeding and then directly on infant nutrition have been investigated. Furthermore, the natural history of food allergy also seems to be changing over time; IgE-mediated cow's milk allergy and egg allergy seem to be more frequently a persistent rather than a transient disease in childhood, as described in the last years. Food avoidance and the emergency drugs in case of an adverse event, such as epinephrine self-injector, are currently the first-line treatment in patients with food allergies, with a resulting impairment in the quality of life and social behaviour. During the last decade, oral immunotherapy emerged as an optional treatment with remarkable results, offering a novel perspective in the treatment for and management of food allergy.

Are allergic multimorbidities and IgE polysensitization associated with the persistence or re-occurrence of foetal type 2 signalling? The MeDALL hypothesis

Allergic diseases [asthma, rhinitis and atopic dermatitis (AD)] are complex. They are associated with allergen-specific IgE and nonallergic mechanisms that may coexist in the same patient. In addition, these diseases tend to cluster and patients present concomitant or consecutive diseases (multimorbidity). IgE sensitization should be considered as a quantitative trait. Important clinical and immunological differences exist between mono- and polysensitized subjects. Multimorbidities of allergic diseases share common causal mechanisms that are only partly IgE-mediated. Persistence of allergic diseases over time is associated with multimorbidity and/or IgE polysensitization. The importance of the family history of allergy may decrease with age. This review puts forward the hypothesis that allergic multimorbidities and IgE polysensitization are associated and related to the persistence or re-occurrence of foetal type 2 signalling. Asthma, rhinitis and AD are manifestations of a common systemic immune imbalance (mesodermal origin) with specific patterns of remodelling (ectodermal or endodermal origin). This study proposes a new classification of IgE-mediated allergic diseases that allows the definition of novel phenotypes to (i) better understand genetic and epigenetic mechanisms, (ii) better stratify allergic preschool children for prognosis and (iii) propose novel strategies of treatment and prevention.

Non-IgE-mediated gastrointestinal food allergy

Non-IgE-mediated gastrointestinal food-induced allergic disorders (non-IgE-GI-FAs) account for an unknown proportion of food allergies and include food protein-induced enterocolitis syndrome (FPIES), food protein-induced allergic proctocolitis (FPIAP), and food protein-induced enteropathy (FPE). Non-IgE-GI-FAs are separate clinical entities but have many overlapping clinical and histologic features among themselves and with eosinophilic gastroenteropathies. Over the past decade, FPIES has emerged as the most actively studied non-IgE-GI-FA, potentially because of acute and distinct clinical features. FPIAP remains among the common causes of rectal bleeding in infants, while classic infantile FPE is rarely diagnosed. The overall most common allergens are cow's milk and soy; in patients with FPIES, rice and oat are also common. The most prominent clinical features of FPIES are repetitive emesis, pallor, and lethargy; chronic FPIES can lead to failure to thrive. FPIAP manifests with bloody stools in well-appearing young breast-fed or formula-fed infants. Features of FPE are nonbloody diarrhea, malabsorption, protein-losing enteropathy, hypoalbuminemia, and failure to thrive. Non-IgE-GI-FAs have a favorable prognosis; the majority resolve by 1 year in patients with FPIAP, 1 to 3 years in patients with FPE, and 1 to 5 years in patients with FPIES, with significant differences regarding specific foods. There is an urgent need to better define the natural history of FPIES and the pathophysiology of non-IgE-GI-FAs to develop biomarkers and novel therapies.

Ovomucoid specific immunoglobulin E as a predictor of tolerance to cooked egg

BACKGROUND

Ovomucoid is the dominant allergen in hen's egg. Although several studies evaluated the utility of ovomucoid specific immunoglobulin E (sIgE) levels in predicting baked (e.g., muffin or cupcake) or raw egg food challenge outcomes, studies that evaluated ovomucoid sIgE as a predictor of cooked egg (e.g., scrambled or hard boiled) challenge outcomes are limited.

OBJECTIVE

To determine the relation of ovomucoid sIgE levels with cooked egg food challenge outcomes.

METHODS

A retrospective review of 44 children who underwent cooked egg food challenge and who had the ovomucoid sIgE level measured.

RESULTS

Thirty-six of 44 children (81.8%) passed cooked egg challenge. The ovomucoid sIgE level predicted cooked egg challenge outcome (passed median, <0.35 kU/L [range, <0.35-0.64 kU/L]; failed median, 0.40 kU/L [range, <0.35-3.13 kU/L]; p = 0.004). Ovomucoid sIgE levels correlated with egg white (EW) sIgE levels (Spearman correlation coefficient, 0.588; p < 0.001). Receiver operating characteristic curve analysis of ovomucoid and EW sIgE demonstrated areas under the curve of 0.711 and 0.766, respectively. No significant difference was observed among those immunologic parameters in their abilities to predict cooked egg challenge outcome (p = 0.559).

CONCLUSION

The ovomucoid sIgE level may be helpful in predicting cooked egg challenge outcomes. However, our study did not support a role for ovomucoid sIgE replacing EW sIgE testing in evaluating egg allergy.

The predictive value of allergen skin prick tests and IgE tests at pre-school age: the PACT study

BACKGROUND

Sensitization toward allergens, as determined by skin prick test (SPT) or specific IgE (sIgE), is a predictor for the later presence of allergy-related disease (atopic eczema, allergic rhinoconjuctivitis and asthma). However, it is not known whether SPT or sIgE should be the preferred test. The aim of this study was to compare the predictive ability of SPT and sIgE when performed in a general population of 2-yr-old children.

METHODS

In a prospective, longitudinal population-based study of children aged 2-6 yr, SPT and sIgE for nine common allergens were performed at 2 yr. Allergy-related disease was evaluated by clinical examination and questionnaire at 2 and 6 yr of age (n = 199).

RESULTS

Skin prick test or sIgE was positive in 10.6% and 21.1% in the 2-yr-old children, respectively. The prevalence of allergy-related disease was 25.6% at 2 yr and 25.1% at 6 yr. Half of the cases at 2 yr were transient. Both SPT and sIgE were statistically significant predictors for later allergy-related disease, OR = 6.5 (95% CI 2.3-18.6) and OR = 4.1 (95% CI 1.9-9.0), respectively. Receiver operating characteristic analysis showed that SPT and sIgE had comparable predictive ability for atopic eczema, asthma or any allergy-related disease, but sIgE had better ability to predict later allergic rhinoconjunctivitis.

CONCLUSION

Sensitization at 2 yr may be useful predictors of allergy-related disease later in childhood. The predictive ability of SPT and sIgE were mainly comparable; however, it may be that sIgE is the preferred choice in young children when the aim is to predict allergic rhinoconjunctivitis.

Diagnosis and management of food allergies: new and emerging options: a systematic review

It is reported that 6% of children and 3% of adults have food allergies, with studies suggesting increased prevalence worldwide over the last few decades. Despite this, our diagnostic capabilities and techniques for managing patients with food allergies remain limited. We have conducted a systematic review of literature published within the last 5 years on the diagnosis and management of food allergies. While the gold standard for diagnosis remains the double-blind, placebo-controlled food challenge, this assessment is resource intensive and impractical in most clinical situations. In an effort to reduce the need for the double-blind, placebo-controlled food challenge, several risk-stratifying tests are employed, namely skin prick testing, measurement of serum-specific immunoglobulin E levels, component testing, and open food challenges. Management of food allergies typically involves allergen avoidance and carrying an epinephrine autoinjector. Clinical research trials of oral immunotherapy for some foods, including peanut, milk, egg, and peach, are under way. While oral immunotherapy is promising, its readiness for clinical application is controversial. In this review, we assess the latest studies published on the above diagnostic and management modalities, as well as novel strategies in the diagnosis and management of food allergy.

Optimisation and use of humanised RBL NF-AT-GFP and NF-AT-DsRed reporter cell lines suitable for high-throughput scale detection of allergic sensitisation in array format and identification of the ECM-integrin interaction as critical factor

We have previously described a microarray platform combining live basophils with protein arrays suitable for high-throughput detection of sensitisation against allergens. During optimisation of this technique, we observed severe losses of adhering cells during the washing steps, particularly after activation. In order to preserve cell binding, we tested the cell adhesion characteristics of different extracellular matrix proteins: human collagen I, fibronectin (FN) from bovine plasma and laminin (LN). FN was more effective than LN and collagen. Cell detachment after activation was in part due to reduced surface expression of VLA-4, the main ligand for FN, which was significantly decreased within 15 min of stimulation with 1 μg/mL calcium ionophore A23187, reaching a minimum after 2 h then slowly recovering. These optimised conditions were used for testing of well-characterised sera from allergic patients using two newly developed rat basophil leukaemia stable reporter cell lines (RBL NF-AT/GFP and RBL NF-AT/DsRed), which both express the human high-affinity IgE receptor alpha chain (FcεRIα). Both cell lines were able to detect sensitisation to specific allergens showing the expected bell-shaped dose–response curve, and correlated (R² = 0.75) with the standard beta-hexosaminidase assay, which is not suitable for an array format.

Tolerance to egg proteins in egg-sensitized infants without previous consumption

BACKGROUND

Egg-sensitized infants who have never eaten egg may react at first ingestion. We sought to determine the association between skin prick test (SPT) and specific IgE (sIgE) to egg proteins (EP) and oral food challenge (OFC) outcomes to find cut-off points which can diagnose egg allergy.

METHODS

One hundred and fifty-four infants up to 18 months, with cow's milk allergy (CMA) and/or atopic dermatitis (AD) without previous egg consumption, were recruited. SPT to EP were performed. If it was positive, sIgE was performed. If positive SPT and/or sIgE (n = 94), OFC was performed between 12 and 18 months. Receiver operating characteristic (ROC) curves were plotted, and the outcome of the OFC was related to SPT and sIgE. The cut-off points with the best diagnostic accuracy were found.

RESULTS

Ninety-four patients were sensitized to egg (69%) and 60 nonsensitized (31%). Of the sensitized, 27 tolerated cooked (CE) and raw egg (RE) (28.7%). Sixty-seven were allergic (71.3%): 29 reacted to CE, seven to egg yolk (EY) and 22 to egg white (EW) and 38 reacted to RE. 69.2% tolerated CE. EW SPT and ovalbumin (OVA) sIgE have the best area under the curve (AUC). The higher positive predictive values (PPV) were obtained for EW SPT and EW sIgE.

CONCLUSIONS

In egg-sensitized infants with EW SPT ≥8 mm and/or EW sIgE ≥8.36 KU/l, egg diagnostic OFC can be avoided as there is 94% probability of becoming positive. In the other patients, OFC should be performed safely and early to avoid unnecessary diets.

Practical interest of both skin prick test and specific IgE in the evaluation of tolerance acquisition in IgE mediated cow's milk allergy (CMA). A clinical retrospective study in a cohort of 184 children

BACKGROUND

Cow's milk protein allergy (CMPA) represents one of the leading causes of food allergy in infants and young children. The immune reaction may be IgE mediated, non-IgE mediated, or mixed. IgE-mediated cow's milk protein allergy is revealed by immediate and acute symptoms which can be severe. The aim of this study is to report a one centre experience in the real life of testing children with IgE-mediated CMPA and try to identify predictive factor for follow-up challenges.

METHOD

Retrospective and monocentric study between September 1997 and February 2008. 178 infants diagnosed with IgE-mediated CMPA during breastfeeding weaning were included. Initial factors such as age, sex, skin prick tests (SPTs), specific IgE (sIgE), atopic dermatitis and types of reaction were noted. Between 12 and 24 months all infants have undergone at least one evaluation including SPT.

RESULTS

At the food challenge, 138 (75.8%) infants were found tolerant. Results of the skin prick test (SPT) were statistically different according to the food challenge result (2.2mm vs. 5.1mm, p<0.0001). It was the same result for sIgE for CM 2.0ku/l vs. 11.5ku/l - p<0.0001 and for casein 1.0ku/l vs. 16.0ku/l - p=0.0014.

CONCLUSION

This study confirms the practical interest of both SPT and sIgE in the evaluation of tolerance induction in IgE-mediated CMPA, but with no corresponding results. Sensitivity, specificity and probability curves of success for cow's milk challenge can be determined and have clinical utility.

Developments in the field of allergy in 2012 through the eyes of Clinical & Experimental Allergy

In 2012, we received 683 submissions and published 20 editorials, 38 reviews, 11 letters and 128 original articles. This represents an acceptance rate for original papers in the range of 20%. About 30% of original papers were triaged not to go out to review, either because the editors did not feel they had sufficient priority for publication or because the topic did not feel right for the readers of the journal. We place great emphasis on obtaining sufficient high-quality reviews to make our decisions on publication fair and consistent. Inevitably, however, there is a degree of luck about what gets published and which papers miss out, and we are always happy to receive an appeal on our decisions either at the triage stage or after review. This gives us the opportunity to revisit the decision and revise it or explain in more detail to the authors the basis for the decision. Once again in 2012, we were delighted by the quality of the papers submitted and the breadth and depth of research into allergic disease that it revealed. The pattern of papers submitted was similar in previous years with considerable emphasis on all aspects of asthma and rhinitis. We were particularly pleased with our special issue on severe asthma. Elucidating mechanisms using either animal models or patients has always been a major theme of the journal, and the excellent work in these areas has been summarized by Harissios Vliagoftis with a particularly interesting section on early-life events guiding the development of allergic disease, which understandably continue to be a major theme of research. Magnus Wickman summarized the papers looking at the epidemiology of allergic disease including work from birth cohorts, which are an increasingly rich source of data on risk factors for allergic disease, and two papers on the epidemiology of anaphylaxis. Giovanni Passalacqua discussed the papers in the clinical allergy section of the journal, and Adriano Mari who runs the excellent Allergome website discussed the papers looking at allergens including characterization and the relative usefulness of allergen arrays versus single extracts in diagnosis and management.

Agreement between the skin prick test and specific serum IgE for egg white and cow's milk allergens in young infant with atopic dermatitis

BACKGROUND

The skin prick test (SPT) for detecting atopic sensitization is not preferred in young infants with atopic dermatitis (AD) because of concerns about poor skin reactivity. This study aimed to evaluate whether the results of SPT agreed well with those of specific serum immunoglobulin E (sIgE) antibody test in young infants with AD.

METHODS

This study included 2,077 eligible infants (age, <12 months) with AD who were tested by either SPT or sIgE between 2007 and 2011. Among them, 199 infants tested for egg white (EW) and 192 infants tested for cow's milk (CM), by both SPT and sIgE on the same day were identified and reviewed retrospectively. Kappa statistics and tests for equal kappa statistics were used to evaluate the agreement between the SPT and sIgE.

RESULTS

The mean wheal diameter and the allergen-to-histamine ratio of SPT showed substantial agreement with those of sIgE for EW (κ = 0.62, 0.69) and CM (κ = 0.34, 0.47). The agreement for EW was significantly higher <6-month-old than in ≥6-month-old infants (κ = 0.79 vs. 0.54, P = 0.02), and that for CM was similar (P = 0.60). The mean wheal diameters for EW and CM were evenly distributed, and did not show increasing trends regardless of age in months (Ptrend = 0.13 and 0.06, respectively).

CONCLUSIONS

The results of SPT agreed well with those of sIgE. This finding provides a rationale for using SPT, and suggests that SPT can be used along with sIgE to detect food sensitization in young infants with AD.

Recombinant allergen-based provocation testing

Over the last 25 years, recombinant allergens from all important allergen sources have been cloned and are now available as recombinant proteins. These molecules can be produced in practically unlimited amounts without biological or batch-to-batch variability. It has been shown in provocation tests that recombinant allergens have similar clinical effects as their natural counterparts. With the help of these tools it is possible to reveal the precise reactivity profiles of patients and to uncover and differentiate cross-reactivity from genuine sensitization to an allergen source. Although it has been shown some time ago that it would be possible to replace crude allergen extracts with recombinant allergens for skin prick testing, and even though the use of allergen components can improve routine diagnosis, these tools are still not available for clinical routine applications. The use of provocation tests is a crucial step in the development of new, hypoallergenic vaccines for therapy of allergic disease. Here we describe important provocation methods (skin prick test, intradermal test, atopy patch test, nasal provocation, colonoscopic provocation test) and give an overview of the clinical provocation studies which have been performed with recombinant allergens so far.

World Allergy Organization Anaphylaxis Guidelines: 2013 update of the evidence base

The World Allergy Organization (WAO) Guidelines for the assessment and management of anaphylaxis are a widely disseminated and used resource for information about anaphylaxis. They focus on patients at risk, triggers, clinical diagnosis, treatment in health care settings, self-treatment in the community, and prevention of recurrences. Their unique strengths include a global perspective informed by prior research on the global availability of essentials for anaphylaxis assessment and management and a global agenda for anaphylaxis research. Additionally, detailed colored illustrations are linked to key concepts in the text [Simons et al.: J Allergy Clin Immunol 2011;127:593.e1-e22]. The recommendations in the original WAO Anaphylaxis Guidelines for management of anaphylaxis in health care settings and community settings were based on evidence published in peer-reviewed, indexed medical journals to the end of 2010. These recommendations remain unchanged and clinically relevant. An update of the evidence base was published in 2012 [Simons et al.: Curr Opin Allergy Clin Immunol 2012;12:389-399]. In 2012 and early 2013, major advances were reported in the following areas: further characterization of patient phenotypes; development of in vitro tests (for some allergens) that help distinguish clinical risk of anaphylaxis from asymptomatic sensitization; epinephrine (adrenaline) research, including studies of a new epinephrine auto-injector for use in community settings, and randomized controlled trials of immunotherapy to prevent food-induced anaphylaxis. Despite these advances, the need for additional prospective studies, including randomized controlled trials of interventions in anaphylaxis is increasingly apparent. This 2013 Update highlights publications from 2012 and 2013 that further contribute to the evidence base for the recommendations made in the original WAO Anaphylaxis Guidelines. Ideally, it should be used in conjunction with these Guidelines and with the 2012 Guidelines Update.

Food allergy diagnosis and therapy: where are we now?

Food allergy is a growing worldwide epidemic that adversely effects up to 10% of the population. Causes and risk factors remain unclear and diagnostic methods are imprecise. There is currently no accepted treatment for food allergy. Therefore, there is an imminent need for greater understanding of food allergies, revised diagnostics and development of safe, effective therapies. Oral immunotherapy provides a particularly promising avenue, but is still highly experimental and not ready for clinical use.

Role of exhaled nitric oxide as a predictor of atopy

BACKGROUND

The fractional exhaled nitric oxide (FeNO) is a quantitative, noninvasive and safe measure of airways inflammation that may complement the assessment of asthma. Elevations of FeNO have recently been found to correlate with allergic sensitization. Therefore, FeNO may be a useful predictor of atopy in the general population. We sought to determine the diagnostic accuracy of FeNO in predicting atopy in a population-based study.

METHODS

We conducted a cross-sectional study in an age- and sex- stratified random sample of 13 to 15 year-olds in two communities in Peru. We asked participants about asthma symptoms, environmental exposures and sociodemographics, and underwent spirometry, assessment of FeNO and an allergy skin test. We used multivariable logistic regression to model the odds of atopy as a function of FeNO, and calculated area-under-the-curves (AUC) to determine the diagnostic accuracy of FeNO as a predictor of atopy.

RESULTS

Of 1441 recruited participants, 1119 (83%) completed all evaluations. Mean FeNO was 17.6 ppb (SD=0.6) in atopics and 11.6 ppb (SD=0.8) in non-atopics (p<0.001). In multivariable analyses, a FeNO>20 ppb was associated with an increase in the odds of atopy in non-asthmatics (OR=5.3, 95% CI 3.3 to 8.5) and asthmatics (OR=16.2, 95% CI 3.4 to 77.5). A FeNO>20 ppb was the best predictor for atopy with an AUC of 68% (95% CI 64% to 69%). Stratified by asthma, the AUC was 65% (95% CI 61% to 69%) in non-asthmatics and 82% (95% CI 71% to 91%) in asthmatics.

CONCLUSIONS

FeNO had limited accuracy to identify atopy among the general population; however, it may be a useful indicator of atopic phenotype among asthmatics.