Allergy to cow's milk proteins: what contribution does hypersensitivity in skin tests have to this diagnosis?

Diagnostic accuracy of atopy patch test in children with cow's milk allergy

BACKGROUND

The accuracy of an atopy patch test (APT) for fresh cow's milk allergy is controversial. Few studies have focused on commercial extract solutions. We aimed to evaluate the diagnostic performance of the APT in cow's milk allergic children using fresh cow's milk and commercial extracts of cow's milk and its components including casein, α-lactalbumin, and β-lactoglobulin.

METHODS

A prospective study was carried out in children with a history of cow's milk allergy. Children underwent the skin prick test (SPT) and APT with fresh cow's milk, powdered cow's milk, and commercial extracts of cow's milk, casein, α-lactalbumin, and β-lactoglobulin. Oral food challenge (OFC) was confirmed in all children.

RESULTS

A total of 37 patients participated (mean age 13.14 ± 7.26 months). Only 5 (13.51%) patients had positive OFC to cow's milk. The sensitivity of the APT using fresh cow's milk was 40%, specificity was 65.6%, PPV was 15.4%, and NPV was 87.5%. The sensitivity of the APT using powdered cow's milk was 40%, 60.7% for specificity, 15.4% for PPV, and 58% for NPV. The sensitivity and PPV of the APT using commercial solutions of cow's milk, casein, α-lactalbumin, and β-lactoglobulin were zero. The specificities were 90.6%, 93.8%, 100%, and 100% for α-lactalbumin, cow's milk, casein, and β-lactoglobulin, respectively.

CONCLUSIONS

APT using commercial solutions showed higher specificity than fresh milk. The specificity increased using a protein component allergen.

Cows' Milk Allergy-Associated Constipation: When to Look for It? A Narrative Review

Constipation is a very common disorder, mostly functional in nature, that may persist for years in up to 35-52% of children. Food allergy prevalence, severity and persistence are increasing over time, and cows' milk protein is the commonest food allergen recognised to affect gastrointestinal motility in children. There is mounting evidence of the role of cows' milk (CM) allergy (CMA) in children with constipation. With this narrative review, we aim to provide clinicians with an updated and critical overview of food allergy-associated constipation. We searched Embase, Medline and the Cochrane Library, using keywords related to the topic. Only reviews and studies including children aged 0-17 years that were published in English were considered. Constipation has been reported in 4.6% of infants with CMA; the prevalence of food allergy underlying chronic constipation in children resistant to conventional treatment and presenting to tertiary clinics ranges between 28% and 78%. The identification of predisposing risk factors and of a specific phenotype of food allergy-induced constipation remains elusive. No allergic tests, radiological or motility investigations achieve sufficient sensitivity and specificity to screen children for CMA-related constipation. A 4-week cows' milk protein (CMP) elimination diet may be considered for children with chronic constipation resistant to conventional treatment and who lack alarm sign/symptoms of organic diseases. In subjects with ameliorated symptoms on CMP elimination, the diagnosis of CMA should be confirmed by a food challenge to avoid an unnecessary protracted diet.

A Survey to Identify the Current Management of Cow’s Milk Disorders and the Role of Goat Milk-Based Formulas in the Middle East and North Africa Region

Background: Cow’s milk allergy (CMA) and cow’s milk intolerance (CMI) are the major cow’s milk disorders observed in infants and young children. This study investigates, for the first time, physician knowledge regarding CMA and CMI prevalence, diagnosis, and management in the Middle East and North Africa (MENA) region. In addition, we explore the role of goat milk-based formula as an alternative in infants suffering from CMI. Method: This cross-sectional survey was conducted from December 2020 to February 2021. A convenience sample of 2500 MENA-based physicians received the questionnaire, developed by a working group of pediatric experts. Results: 1868 physicians completed the questionnaire, including pediatric specialists (80.8%), training physicians (0.2%), dermatologists (0.1%), family/general physicians (12.9%), neonatologists (3.6%), neurosurgeons (0.2%), allergy nurse specialists (0.3%), pharmacists (2.1%), and public health workers (0.1%). Differentiation between CMA and CMI was recognized by the majority of respondents (80.7%), for which the majority of respondents (35.4%) identified that the elimination and challenge test was the best test to differentiate CMA from CMI, whereas 30.7% and 5.4% preferred the immunoglobulin E (IgE) test and skin prick test, respectively. In addition, 28.5% of respondents reported that there is no confirmatory test to differentiate CMA from CMI. The majority of respondents (47.3%) reported that amino acid-based formula (AAF)/ extensively hydrolyzed formula (EHF) is the cornerstone for the management of CMA. However, most respondents (33.7%) reported that lactose avoidance was best for the management of CMI. Overall, 65% of the respondents were aware of nutritionally adapted goat’s milk formula as an alternative to cow’s milk products and 37% would recommend its routine use in infants (≤2 years of age). Conclusion: The results of this survey demonstrate that the majority of physicians are aware of the underlying pathophysiology and management of CMA and CMI. However, a significant proportion of physicians do not follow the clinical guidelines concerning CMA/CMI diagnosis and management. Notably, this survey identified that goat’s milk formulas may offer a suitable alternative to AAF/EHF in infants with CMI as they contain β-casein protein which is easily digestible. In addition, goat’s milk formulas contain higher levels of oligosaccharides and medium-chained fatty acids compared with standard cow’s milk formulas, yet further clinical trials are warranted to support the inclusion of goat’s milk formulas in clinical guidelines.

Atopy patch test in children with cow's milk and hen's egg allergy: Do clinical symptoms matter?

INTRODUCTION AND OBJECTIVES

Since early 2000s, atopy patch test (APT) has been used to determine non-IgE and mixed-type food allergies. Previous studies have reported conflicting results about the diagnostic value of APT in food allergies, due to non-standardized methods. We aimed to determine the diagnostic efficacy of APT compared to open oral food challenge (OFC) in patients diagnosed with cow's milk allergy (CMA) and hen's egg allergy (HEA) manifesting as atopic dermatitis (AD) and gastrointestinal system symptoms.

MATERIALS AND METHODS

In patients with suspected AD and/or gastrointestinal manifestations due to CMA and HEA, the results of OFC, APT, skin prick test (SPT) and specific IgE (sIgE) were reviewed. Specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of sIgE, SPT, APT and SPT+APT were calculated.

RESULTS

In total 133 patients with suspected CMA (80) and HEA (53) were included in the study. In patients with CMA presenting with gastrointestinal symptoms, APT had sensitivity of 9.1%, specificity of 100%, PPV of 100% and NPV of 48.7%. In atopic dermatitis patients, sensitivity of APT was 71.4%, specificity 90.6%, PPV 62.5% and NPV 93.6%. In patients diagnosed with HEA, the sensitivity, specificity, PPV and NPV values of APT were 72.0%, 78.6%, 47.2% and 75.0%, respectively. In patients diagnosed with HEA presenting with AD, sensitivity of APT was 87.5%, specificity 70.6%, PPV 73.7% and NPV 85.7%. Atopy patch test had lower sensitivity (44.4%) and higher specificity (90.9%) in patients diagnosed with HEA presenting with gastrointestinal symptoms than those presenting with AD.

CONCLUSION

Our study showed that APT provided reliable diagnostic accuracy in atopic dermatitis patients. However, APT had low sensitivity in patients with gastrointestinal symptoms.

Probiotics for cow's milk protein allergy: a systematic review of randomized controlled trials

Cow's milk protein allergy (CMPA) is the commonest food allergy in infancy and is associated with significant health burden. Given their immune modulatory properties, probiotics have been proposed as a strategy for management of CMPA. We aimed to systematically review efficacy and safety of probiotics in the management of CMPA. Databases PubMed, EMBASE, CINAHL, Cochrane Central Library, and Google scholar were searched in August 2018 for randomized controlled trials (RCT) of probiotic supplementation as an adjunct in the management of infants with suspected/proven CMPA. Primary outcomes were resolution of hematochezia and acquisition of tolerance to CMP at 6, 12, 24, and 36 months. Secondary outcomes included effect on allergic symptoms (SCORAD index), growth, gut microbiota, and adverse effects. A total of 10 RCTs (n = 845; probiotics, 422; control, 423) with low to unclear risk of bias were included. Meta-analysis showed probiotic supplementation was not associated with earlier resolution of hematochezia (n = 87; RR: 1.45 (95% CI: 0.96-2.18), p = 0.08; level of evidence (LOE), very low), in presumed CMPA. In confirmed CMPA, probiotics were associated with higher rate of acquisition of tolerance to CMP at the end of 3 years compared with placebo (N = 493; RR, 1.47; 95% CI, (1.17-1.84); p = 0.0009; LOE, low]. Meta-analysis was not possible for other outcomes. There were no probiotic related adverse effects. Conclusion: Limited low-quality evidence indicates that probiotic supplementation may be associated with earlier acquisition of tolerance to CMP in children with CMPA. Large well-designed trials are essential to confirm these findings. What is Known: • Cow's milk protein allergy (CMPA) is one of the commonest food allergies in children. CMPA is associated with significant socioeconomic burden. • Elimination diet and extensively hydrolyzed formula is the mainstay of the management of CMPA. What is New: • This first systematic review of randomized controlled trials shows that probiotics as an adjuvant can lead to earlier acquisition of tolerance to CMP in children at 36 months of age. However, the evidence is low quality and influenced by data from one large study. • Probiotic supplementation was not associated with earlier resolution of hematochezia.

Prevention of Allergic Sensitization and Treatment of Cow's Milk Protein Allergy in Early Life: The Middle-East Step-Down Consensus

Allergy risk has become a significant public health issue with increasing prevalence. Exclusive breastfeeding is recommended for the first six months of life, but this recommendation is poorly adhered to in many parts of the world, including the Middle-East region, putting infants at risk of developing allergic sensitization and disorders. When breastfeeding is not possible or not adequate, a partially hydrolyzed whey formula (pHF-W) has shown proven benefits of preventing allergy, mainly atopic eczema, in children with a genetic risk. Therefore, besides stimulating breastfeeding, early identification of infants at risk for developing atopic disease and replacing commonly used formula based on intact cow milk protein (CMP) with a clinically proven pHF-W formula is of paramount importance for allergy prevention. If the child is affected by cow’s milk protein allergy (CMPA), expert guidelines recommend extensively hydrolyzed formula (eHF), or an amino acid formula (AAF) in case of severe symptoms. The Middle-East region has a unique practice of utilizing pHF-W as a step-down between eHF or AAF and intact CMP, which could be of benefit. The region is very heterogeneous with different levels of clinical practice, and as allergic disorders may be seen by healthcare professionals of different specialties with different levels of expertise, there is a great variability in preventive and treatment approaches within the region itself. During a consensus meeting, a new approach was discussed and unanimously approved by all participants, introducing the use of pHF-W in the therapeutic management of CMPA. This novel approach could be of worldwide benefit.

The diagnostic value of APT for food allergy in children: a systematic review and meta-analysis

BACKGROUND

The role of atopy patch test (APT) in the diagnosis of food allergy (FA) remains largely controversial. In our meta-analysis, we aimed to evaluate the accuracy of APT for diagnosing FA in children.

METHODS

Pubmed, Embase and Cochrane Library were searched for studies regarding the diagnostic value of APT for FA in children compared to oral food challenge (double-blind placebo-controlled food challenge and/or open food challenge). The last search was conducted on November 11, 2017. Two reviewers independently screened relevant studies and assessed the quality by QUADAS-2. Meta-analysis was performed to calculate the pooled sensitivity, specificity, DOR (diagnostic odds ratio), PLR (positive likelihood ratio), NLR (negative likelihood ratio) with their 95% confidence intervals (CIs). Subgroup analyses were conducted according to different food allergens, atopic dermatitis, gastrointestinal symptoms, and age younger than 3 years.

RESULTS

Forty-one studies were included in the meta-analysis. The pooled sensitivity, specificity, PLR, NLR and DOR were 50.30% (95% CI 48.40%-52.30%), 86.60% (95% CI 85.30%-87.80%), 3.405 (95% CI 2.594-4.470), 0.545 (95% CI 0.469-0.634) and 7.528 (95% CI 5.507-11.206), respectively. However, for children with FA-related gastrointestinal symptoms, the pooled sensitivity and specificity were 57.40% (95% CI 52.10%-62.50%) and 91.50% (95% CI 88.30%-94.10%) respectively.

CONCLUSIONS

Our findings suggest that APT is specific but not sensitive for diagnosing FA in children, especially in children with FA-related gastrointestinal symptoms.

The establishment of cow's milk protein allergy in infants is related with a deficit of regulatory T cells (Treg) and vitamin D

BACKGROUND

Cow's milk protein allergy (CMPA) is the most common food allergy in infants. However, little is known about which specific immune mechanisms are related with the CMPA onset. The objective was to investigate which immune alterations constitute differential factors between allergy and tolerance, and hence could be implicated in the CMPA establishment in infants.

METHODS

An extensive analysis of immune subsets, including Treg and cytokine-secreting cells was performed in blood samples from 28 infants younger than 9 mo obtained 1-4 d after the first adverse reaction to milk.

RESULTS

Less than 4 d after first allergic reaction, infants who developed CMPA had decreased Treg counts and increased frequency of IL4-secreting CD4 T cells compared to controls. The deficit of Tregs was correlated with decreased serum levels of vitamin D. Values of Tregs, IL4-secreting cells and vitamin D were good predictors of CMPA diagnosis. Basal vitamin D levels in CMPA infants also predicted those CMPA patients developing spontaneous tolerance in the first year.

CONCLUSION

Establishment of CMPA in infants was related with lower Treg and vitamin D levels. These immune alterations would be crucial factors behind the CMPA establishment and they could constitute a therapeutic target for treatment of CMPA.

Role of specific IgE to β-lactoglobulin in the gastrointestinal phenotype of cow's milk allergy

Rationale

The prevalence of many phenotypes of food allergy is increasing. Specific gastrointestinal (GI) phenotype of food allergy (GI allergy) is also increasing but it is difficult to know the prevalence because of many entities.

Methods and Results

A 1 year retrospective study of pediatric patients complaining exclusively gastrointestinal symptoms after cow’s milk consumption and at least one positive specific IgE (sIgE) to cow’s milk (CM) proteins (CMP) was done (n = 39). The most prevalent symptom was abdominal cramps in 35 patients (90 %), discomfort or abdominal distention in 30 patients (75 %), diarrhea in 10 patients (25 %) and constipation in 5 patients (12 %). IgA anti-transglutaminase antibodies were absent and lactose intolerance was ruled out in all patients. Average of total IgE on this group was 288 UI/ml. sIgE against β-lactoglobulin was the dominant with an average of 4.14 kU/l. sIgE to casein (CAS), which is the dominant protein in systemic anaphylaxis was 1.74 kU/l; sIgE to α-lactoalbumin, the other whey protein, was 0.83 kU/l and sIgE levels to CM were 0.78 kU/l. The quotient sIgE CAS/sIgE β-lactoglobulin in these patients was always lower than 1. Patients experienced an improvement of their symptoms after a CM free diet. An open oral challenge with CM did mimic their initial symptoms in all patients. However, the open oral challenge with dairy products was well tolerated.

Conclusions

Patients with a specific phenotype of GI allergy with CM have specific IgE against β-lactoglobulin, as a dominant sIgE. These patients could beneficiate of a diet with dairy products.

Diagnostic accuracy of patch test in children with food allergy

BACKGROUND

The gold standard test for confirming whether a child has clinical hypersensitivity reactions to foods is the oral food challenge. Therefore, there is increasing interest in simpler diagnostic markers of food allergy, especially in children, to avoid oral food challenge. The goal of this study was to assess the diagnostic accuracy of atopy patch test in comparison with oral food challenge.

METHODS

We investigated 243 children (mean age, 51 months) referred for evaluation of suspected egg or cow's milk allergy. Skin prick test and atopy patch test were carried out, and after a 2 weeks elimination diet, oral food challenge was performed.

RESULTS

Two hundred and forty-three children underwent OFC to the suspected food. We found clinically relevant food allergies in 40 (65%) children to egg and in 22 (35%) to cow's milk. The sensitivity of skin prick test for both milk and egg was 92%, specificity 91%, positive predictive value 35%, and negative predictive value of 93%. Sensitivity, specificity, positive predictive value, and negative predictive value of atopy patch test for both milk and egg were 21%, 73%, 20%, and 74%, respectively.

CONCLUSION

Our study suggests that there is insufficient evidence for the routine use of atopy patch test for the evaluation of egg and cow's milk allergy. OFC remains gold standard for the diagnosis of egg and milk allergy even in the presence of high costs in terms of both time and risks during application.

Clinical Parameters vs Cytokine Profiles as Predictive Markers of IgE-Mediated Allergy in Young Children

Background

Allergy afflicts one third of children, negatively impacting their quality of life and generating a significant socio-economic burden. To this day, this disorder remains difficult to diagnose early in young patients, with no predictive test available.

Objective

This study was designed to correlate cytokine profiles with clinical phenotypes of allergy development.

Methods

Three hundred patients were recruited and followed from birth to 18 months of age. They were given a clinical exam at birth and at 2, 6, 12, and 18 months of age, with skin prick tests at 6, and 18 months, in order to have a record of their medical history and determine their allergic status. In addition, mononuclear cells from 131 patients were isolated from cord blood and from peripheral blood samples at 2, 6 and 18 months of age, to analyse their cytokine and chemokine production.

Results

Cord blood mononuclear cells (CBMCs) from future Immunoglobulin (Ig) E-mediated allergic children produced significantly less Interleukin (IL)-12p70 and IL-15 than cells from the rest of the cohort. Multivariate analyses revealed that the best predictive model of allergy was built on cytokine data, whereas the best predictive model of IgE-mediated allergy was built on clinical parameters.

Conclusions and clinical relevance

Although univariate analyses can yield interesting information regarding the immune responses of allergic children, finding predictive markers of the disorder will likely rely on monitoring multiple parameters. Nonetheless these analyses suggest a potential key role for IL-15 in the development of atopic disease. In addition, the study highlights the importance of clinical parameters in predicting the development of IgE-mediated allergy.

Middle East Consensus Statement on the Prevention, Diagnosis, and Management of Cow's Milk Protein Allergy

Presented are guidelines for the prevention, diagnosis, and treatment of cow's milk protein allergy (CMPA) which is the most common food allergy in infants. It manifests through a variety of symptoms that place a burden on both the infant and their caregivers. The guidelines were formulated by evaluation of existing evidence-based guidelines, literature evidence and expert clinical experience. The guidelines set out practical recommendations and include algorithms for the prevention and treatment of CMPA. For infants at risk of allergy, appropriate prevention diets are suggested. Breastfeeding is the best method for prevention; however, a partially hydrolyzed formula should be used in infants unable to be breastfed. In infants with suspected CMPA, guidelines are presented for the appropriate diagnostic workup and subsequent appropriate elimination diet for treatment. Exclusive breastfeeding and maternal dietary allergen avoidance are the best treatment. In infants not exclusively breastfed, an extensively hydrolyzed formula should be used with amino acid formula recommended if the symptoms are life-threatening or do not resolve after extensively hydrolyzed formula. Adherence to these guidelines should assist healthcare practitioners in optimizing their approach to the management of CMPA and decrease the burden on infants and their caregivers.

How to reintroduce cow's milk?

In a child that is allergic to milk, the natural next step, following the elimination diet, is the reintroduction of cow's milk. Several questions may arise. When feasible, this reintroduction has many benefits for the child and his family. However, the disease needs to be well defined by physicians and explained to parents. They need to understand that there are different types of allergy to cow's milk, specifically IgE- and non-IgE-mediated, and each of these may exhibit both a variable duration and frequently an incomplete recovery. Deciding where to first reintroduce cow's milk to a child who has previously followed a milk-free diet, whether it be at home or in a hospital, also frequently presents an issue. Following this first reintroduction, the progressive increase of milk into the diet needs to be managed properly, as not all children will go back to a normal dairy products intake. Recent studies show that most children with milk allergy tolerate products containing baked milk and that their consumption might speed up recovery. Hence, the purpose of the milk challenge in a child on a milk-free diet is becoming, even in a child still reactive to milk, the first step of gradual and individually adapted reintroduction of milk or dairy products. When reintroduction of cow's milk does not work, immunotherapy becomes an option, and this is carried out in specialized centers.

Milk-induced wheezing in children with asthma

BACKGROUND

Food allergy has been gaining increasing attention, mostly as causing gastrointestinal and cutaneous reactions. Its role in asthma seems to be under-recognised.

OBJECTIVES

This study's aim is to explore the frequency of involvement of a common food, namely cow's milk, in childhood asthma.

METHODS

32 children (5 months to 11 years; median 24 months; mean 34 months) with asthma and a suspected history of cow's milk allergy were studied. They underwent skin prick testing (SPT) and specific IgE (sIgE) testing to whole cow's milk (WCM), casein, α-lactalbumin, and β-lactoglobulin, followed by single-blind oral milk challenge.

RESULTS

Reactions to milk challenge occurred in 12 (37.5%) including wheezing in 5 (41.7%, or 15.6% of the whole group). Children who developed wheezing at the time of challenge were younger than those who had negative challenge (23.0 months vs. 34.8 months). Challenge was positive in 33.3% of subjects who had a positive SPT, and SPT was positive in 50% of challenge-positive subjects. Regarding sIgE, challenge was positive in 26.7% of sIgE-positive subjects, and sIgE was positive in 33.3% of challenge positive subjects. Skin or serum testing with individual protein fractions did not seem to add significant advantage over testing with WCM alone.

CONCLUSION

This study shows that cow's milk can cause wheezing in children with asthma. Although SPT seemed to be more reliable than sIgE testing, both had suboptimal reliability. It is worth considering possible milk allergy in children with asthma, particularly when poorly controlled in spite of proper routine management.

Cow's milk allergy: from allergens to new forms of diagnosis, therapy and prevention

The first adverse reactions to cow's milk were already described 2,000 years ago. However, it was only 50 years ago that several groups started with the analysis of cow's milk allergens. Meanwhile the spectrum of allergy eliciting proteins within cow's milk is identified and several cow's milk allergens have been characterized regarding their biochemical properties, fold and IgE binding epitopes. The diagnosis of cow's milk allergy is diverse ranging from fast and cheap in vitro assays to elaborate in vivo assays. Considerable effort was spent to improve the diagnosis from an extract-based into a component resolved concept. There is still no suitable therapy available against cow's milk allergy except avoidance. Therefore research needs to focus on the development of suitable and safe immunotherapies that do not elicit severe side effect.

Cow's milk associated rectal bleeding: a population based prospective study

BACKGROUND

Isolated rectal bleeding in infants is often attributed to the consumption of cow's milk. However, the prevalence of this condition has not been described, and its preferred diagnostic methods and management are controversial.

METHODS

In a prospective population-based study following 13,019 children from birth, 21 infants with isolated rectal bleeding attributed to cow's milk protein consumption were identified. Following evaluation, parents were encouraged to resume cow's milk protein and infants were followed for reappearance of symptoms and thereafter for 6 yr. In addition, infants with rectal bleeding were compared to a control group of healthy infants.

RESULTS

The prevalence of isolated rectal bleeding attributed to cow's milk consumption was 0.16%. All infants were asymptomatic within days of dietary modifications. Eleven of the 14 infants (78.5%) whose parents reintroduced cow's milk protein to their diet following our evaluation tolerated it with no adverse effects. Those 11 infants were significantly younger at initial consumption of cow's milk protein (6.7 ± 1.6 months) compared to those who continued elimination diet (17.7 ± 9.2 months), (p = 0.002) while their 1-yr hemoglobin levels were comparable (p = 0.98). No risk factors for rectal bleeding were identified.

CONCLUSIONS

The prevalence of isolated rectal bleeding attributed to cow' milk is low. The condition is generally benign and resolves quickly with elimination diet. Reintroduction of cow's milk following resolution of symptoms is often well tolerated and is recommended for confirming the diagnosis and avoiding prolonged unnecessary elimination diets.

Food allergy and anaphylaxis in pediatrics: update 2010-2012

This review highlights the progress made in food allergy (FA) and anaphylaxis research in pediatrics published in the journal Pediatric Allergy and Immunology since 2010. Putative risk factors for FA are as follows: a family history of allergic disease, particularly in the mother, low birth order, season of birth, and severe atopic eczema. Obstetric practices, antibiotic use, and home environment are factors deserving further research. Diagnostic decision levels and component-specific IgE are useful in the diagnosis of FA; however, oral food challenges remain the gold standard and may also be a means to reduce parental anxiety and to improve education. Oral immunotherapy studies show promise in increasing the threshold of reactivity of allergic patients and therefore improving their quality of life. In single-nut-allergic patients, introduction of other nuts allows broadening the diet and thus reducing the psychological impact of allergen avoidance. Nutritional deficiencies are not uncommon in food-allergic children and should be specifically assessed. The prescription of injectable adrenaline is still insufficient and not consistent among practitioners, requiring improved training and implementation of guidelines. Current research into the epidemiology and immunological mechanisms of FA and tolerance will enable us to devise strategies to both prevent and treat food allergies.

In search of a tolerance-induction strategy for cow's milk allergies: significant reduction of beta-lactoglobulin allergenicity via transglutaminase/cysteine polymerization

OBJECTIVE

To explore the use of β-lactoglobulin polymerized using microbial transglutaminase and heating to identify whether protein polymerization could reduce in vivo allergenicity and maintain in vitro and ex vivo immunoreactivity for use in tolerance-induction protocols.

METHODS

Based on previous protocols applied in mice and children, we performed in vivo challenges (using a skin prick test) with native and polymerized β-lactoglobulin in adult patients with an IgE-mediated allergy to plactoglobulin. In vitro humoral immunoreactivity was analyzed using immunoblotting. Cell-mediated immunoreactivity was analyzed using ex vivo challenges with native and polymerized β-lactoglobulin and monitored by leukocyte adherence inhibition tests.

RESULTS

The skin tests demonstrated that there was a significant reduction in immediate cutaneous reactivity after polymerization. Polymerization did not decrease the immunoblotting detection of s-IgE specific to β-lactoglobulin. Cell-mediated immunoreactivity, as assessed by ex vivo challenges and leukocyte adherence inhibition tests, did not exhibit significant differences between leukocytes challenged with native versus polymerized β-lactoglobulin.

CONCLUSIONS

The polymerization of β-lactoglobulin decreased in vivo allergenicity and did not decrease in vitro humoral or ex vivo cell-mediated immunoreactivity. Therefore, we conclude that inducing polymerization using transglutaminase represents a promising technique to produce suitable molecules for the purpose of designing oral/ sublingual tolerance induction protocols for the treatment of allergies.

Specific oral desensitization in children with IgE-mediated cow's milk allergy. Evolution in one year

Cow's milk allergy is the most frequent childhood food allergy. Children older than 5 who have not become tolerant have less probabilities of natural tolerance. Specific oral desensitization methods are being investigated in reference centres. The aims of our study were to assess the efficacy of our guideline of specific oral desensitization to cow's milk in children and to know its suitability for anaphylactic children. Both clinical and specific IgE outcomes were evaluated. Eighty-seven children aged 5 to 16 years with a history of cow's milk allergy were included. Prior to desensitization, skin prick test, specific IgE to cow's milk proteins and a double-blind placebo control food challenge were performed in all. Of the 87 patients, 21 had a negative challenge; they were considered tolerant, and they were told to follow a free diet. Of the positive, 44 were anaphylactic and 22 non-anaphylactic. All of them were included. In non-anaphylactic patients, 6 achieved partial and 16 maximum desensitization after 23.1 weeks. In the anaphylactic group, 7 achieved partial and 35 maximum desensitization after 26.4 weeks. Cow's milk-specific IgE levels and casein-specific IgE levels were significantly lower in the tolerant patients at baseline. One year after desensitization, the medium specific cow's milk levels and casein IgE levels had dropped significantly.

CONCLUSIONS

Our guideline for specific oral desensitization to cow's milk is efficacious even in patients with anaphylactic reactions to cow's milk and represents a significant life change. Immunological changes in 1 year show a drop in cow's milk protein-specific IgE.

Diagnosis and management of cow's milk protein allergy in infants

BACKGROUND

Cow's milk protein allergy (CMPA) is frequently suspected in infants with a variety of symptoms. A thorough history and careful clinical examination are necessary to exclude other underlying diseases and to evaluate the severity of the suspected allergy. Care should be taken to diagnose CMPA adequately to avoid an unnecessary diet.

DATA SOURCES

We make recommendations based on systematic literature searches using the best-available evidence from PubMed, Cumulative Index to Nursing and Allied Health Literature, and bibliographies.

RESULTS

Skin prick tests, patch tests and serum specific IgE are only indicative of CMPA. Breastfed infants have a decreased risk of developing CMPA; an elimination diet for the mother is indicated if CMPA is confirmed. If a food challenge is positive in formula fed infants, an extensively hydrolysed formula and cow's milk-free diet is recommended. If symptoms do not improve, an amino acid based formula should be considered. In severe CMPA with life-threatening symptoms, an amino-acid formula is recommended.

CONCLUSIONS

Elimination diet by a double-blind placebo controlled food challenge is the gold standard for diagnosis. Elimination of the offending allergen from the infants' diet is the main treatment principle.