Natural history of IgE-dependent food allergy diagnosed in children during the first three years of life

The future of cow's milk allergy - milk ladders in IgE-mediated food allergy

Cow's milk allergy (CMA) is one of the most common and complex presentations of allergy in early childhood. CMA can present as IgE and non-IgE mediated forms of food allergy. Non-IgE mediated CMA includes food protein-induced enterocolitis syndrome (FPIES), eosinophilic gastrointestinal disorders (EGIDs), and food protein-induced proctocolitis (FPIAP). There are recent guidelines addressing CMA diagnosis, management, and treatment. Each of these guidelines have their own strengths and limitations. To best manage CMA, individualized avoidance advice should be given. Cow's milk (CM) can be replaced in the diet by using hypoallergenic formulas or plant-based milk, depending on factors such as the child's age and their current food intake. Oral and epicutaneous immunotherapy is used to increase tolerance in children with CMA but is not without risk, and the long-term outcome of sustained unresponsiveness is still unclear. The allergenicity of CM proteins are affected differently by different forms of heating, leading to the use of baked milk or milk ladders in the management of CMA, most likely the most promising option for future management and treatment of CMA. Future management of children with CMA will also include discussion around the immunomodulatory potential of the child's dietary intake.

Prevalence estimates of eight big food allergies in Europe: Updated systematic review and meta-analysis

In 2014, the European Academy of Allergy and Clinical Immunology published prevalence estimates for food allergy (FA) and food sensitization (FS) to the so-called eight big food allergens (i.e. cow's milk, egg, wheat, soy, peanut, tree nuts, fish and shellfish) in Europe for studies published between 2000 and 2012. The current work provides 10-year updated prevalence estimates for these food allergens. A protocol was registered on PROSPERO before starting the research (reference number CRD42021266657). Six databases were searched for studies published 2012-2021, added to studies published up to 2012, resulting in a total of 93 studies. Most studies were graded as at moderate risk of bias. The overall pooled estimates for all age groups of self-reported lifetime prevalence were as follows: cow's milk (5.7%, 95% confidence interval 4.4-6.9), egg (2.4%, 1.8-3.0), wheat (1.6%, 0.9-2.3), soy (0.5%, 0.3-0.7), peanut (1.5%, 1.0-2.1), tree nuts (0.9%, 0.6-1.2), fish (1.4%, 0.8-2.0) and shellfish (0.4%, 0.3-0.6). The point prevalence of food challenge-verified allergy were as follows: cow's milk (0.3%, 0.1-0.5), egg (0.8%, 0.5-1.2), wheat (0.1%, 0.01-0.2), soy (0.3%, 0.1-0.4), peanut (0.1%, 0.0-0.2), tree nuts (0.04%, 0.02-0.1), fish (0.02%, 0.0-0.1) and shellfish (0.1%, 0.0-0.2). With some exceptions, the prevalence of allergy to common foods did not substantially change during the last decade; variations by European regions were observed.

Food Allergies and Parasites in Children

The dynamically growing incidence of food allergies forces the scientific community to develop new methods for their diagnosis, differentiation, and effective treatment. Parasitoses appear much less frequently in the scientific literature, as well as among the presumed causes of numerous conditions. The similarity of inflammatory mechanisms in allergies and parasitosis necessitates a revision of current diagnostic standards. A lack of specificity and the coincidence of symptoms at an early stage of disease can lead to misdiagnosis. In this paper, we attempted to perform a comparative analysis of the similarities and differences in symptoms for these two types of diseases. We described the molecular mechanisms and metabolic pathways of food allergy and parasitosis. We presented the available research methods and directions of ongoing studies aimed at implementing precise medical techniques for differential diagnosis. We discussed the allergenic properties of certain parasite proteins, using the example of myofibrillar tropomyosins from the nematode Anisakis simplex. The literature in the fields of allergology and parasitology leads to the conclusion that it is reasonable to run parallel allergological and parasitological diagnostics in patients with non-specific symptoms. This approach will facilitate accurate and early diagnosis and implementation of effective therapy.

Frequency of food allergy in Europe: An updated systematic review and meta-analysis

Food allergy (FA) is increasingly reported in Europe, however, the latest prevalence estimates were based on studies published a decade ago. The present work provides the most updated estimates of the prevalence and trends of FA in Europe. Databases were searched for studies published between 2012 and 2021, added to studies published up to 2012. In total, 110 studies were included in this update. Most studies were graded as moderate risk of bias. Pooled lifetime and point prevalence of self-reported FA were 19.9% (95% CI 16.6-23.3) and 13.1% (95% CI 11.3-14.8), respectively. The point prevalence of sensitization based on specific IgE (slgE) was 16.6% (95% CI 12.3-20.8), skin prick test (SPT) 5.7% (95% CI 3.9-7.4), and positive food challenge 0.8% (95% CI 0.5-0.9). While lifetime prevalence of self-reported FA and food challenge positivity only slightly changed, the point prevalence of self-reported FA, sIgE and SPT positivity increased from previous estimates. This may reflect a real increase, increased awareness, increased number of foods assessed, or increased number of studies from countries with less data in the first review. Future studies require rigorous designs and implementation of standardized methodology in diagnosing FA, including use of double-blinded placebo-controlled food challenge to minimize potential biases.

Predictors of Persistent Wheat Allergy in Children: A Retrospective Cohort Study

BACKGROUND

Wheat allergy is the third most common food allergy that develops during infancy in Japan. To identify factors associated with persistent wheat allergy, we assessed the rate of tolerance acquisition among Japanese children aged less than 6 years with an immediate-type wheat allergy using the oral food challenge (OFC) method.

METHODS

This retrospective cohort study included 83 children (born in 2005-2006) who had a history of immediate-type allergic reaction to wheat and were followed until 6 years of age. The subjects were divided to form "tolerant" (n = 55; tolerance acquired by 6 years of age) and "allergic" (n = 28; tolerance not acquired by 6 years of age) groups based on their OFC results.

RESULTS

The rates of tolerance acquisition to 200 g of udon noodles at 3, 5, and 6 years of age were 20.5% (17/83), 54.2% (45/83), and 66.3% (55/83), respectively. The total number of anaphylactic reactions experienced prior to 3 years of age in response to all foods (p < 0.01) and to wheat (p = 0.043) was significantly higher in the allergic than in the tolerant group. Wheat- and ω-5 gliadin-specific immunoglobulin E (IgE) levels were significantly higher in the allergic group than in the tolerant group (p < 0.01), and wheat-specific IgE levels were more likely to increase after infancy in the allergic group.

CONCLUSIONS

A history of anaphylaxis to all foods including wheat and/or a high level of wheat- or ω-5 gliadin-specific IgE antibodies were identified as risk factors for persistent wheat allergy.

Natural history of immediate-type hen's egg allergy in Japanese children

BACKGROUND

Hen's egg (HE) allergy develops during infancy. We investigated tolerance acquisition in Japanese children allergic to HE aging <6 years.

METHODS

In this retrospective study, 226 children born in 2005 with a history of immediate-type HE allergy underwent an oral food challenge (OFC). Tolerance was defined as no reaction to an OFC with half of whole heated HE or accidental HE consumption at home. Participants were divided into three groups based on age at tolerance acquisition: group I (<3 years) (n = 66), group II (3-6 years) (n = 98), and group III (prolonged allergic groups) (n = 62).

RESULTS

Tolerance acquisition occurred in 30% (66/226) by 3 years of age, 59% (133/226) by 5 years of age, and 73% (164/226) at 6 years of age. At 3 years, incidences of allergy-related complications (bronchial asthma, p = 0.02; atopic dermatitis, p = 0.04) were higher in the group III than in the group I. Anaphylaxis to any food occurred more frequently in the group III than in the group I (p = 0.03); anaphylaxis to HE was more common in the group III (p = 0.04). Egg white (EW)- and ovomucoid (OM)-specific immunoglobulin E (IgE) levels were higher in the group III than in the group I (p < 0.05).

CONCLUSIONS

The group III experienced HE-related anaphylaxis and complications more frequently and exhibited sustained, high EW- and OM-specific IgE levels.

Baked milk- and egg-containing diet in the management of milk and egg allergy

Cow's milk (CM) and hen's egg allergies are among the most common food allergies in children. With evidence of increasing food allergy prevalence and more persistent disease, it has become vital to improve the management of CM and egg allergies. The ability to tolerate baked milk or egg, such as in a cake or muffin, has been associated with an increased chance of tolerance development. Studies report that about 70% of CM- and egg-allergic children can tolerate baked milk or egg and that incorporating baked milk or egg into the diet is well tolerated. Being able to add baked milk or egg into the diet can also increase quality of life by expanding the diet, boosting nutrition, and promoting inclusion in social activities. There is some debate over how baked milk and egg should be introduced, at home or in a supervised setting. Anaphylaxis and treatment with epinephrine during baked milk or egg challenges have been reported. Study of potential biomarkers to predict tolerability of baked milk and egg, such as serum specific IgE levels and skin prick test wheal diameters, is ongoing. Many parents can reliably report that their CM- or egg-allergic child is already consuming baked goods without symptoms. However, for those who cannot report such tolerance, the most prudent approach is to perform a supervised oral food challenge to determine the tolerability of baked milk and egg. The purpose of this article was to review the pathophysiology, clinical data, and safety of baked milk and egg and provide a practical guide to managing CM allergy and/or egg allergy. Recipes for baked milk and egg challenges and guidance on how to add baked milk and egg if tolerated to the child's regular diet are provided.

Prevalence of common food allergies in Europe: a systematic review and meta-analysis

Allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish constitutes the majority of food allergy reactions, but reliable estimates of their prevalence are lacking. This systematic review aimed to provide up-to-date estimates of their prevalence in Europe.Studies published in Europe from January 1, 2000, to September 30, 2012, were identified from searches of four electronic databases. Two independent reviewers appraised the studies and extracted the estimates of interest. Data were pooled using random-effects meta-analyses. Fifty studies were included in a narrative synthesis and 42 studies in the meta-analyses. Although there were significant heterogeneity between the studies, the overall pooled estimates for all age groups of self-reported lifetime prevalence of allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish were 6.0% (95% confidence interval: 5.7-6.4), 2.5% (2.3-2.7), 3.6% (3.0-4.2), 0.4% (0.3-0.6), 1.3% (1.2-1.5), 2.2% (1.8-2.5), and 1.3% (0.9-1.7), respectively. The prevalence of food-challenge-defined allergy to cow's milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish was 0.6% (0.5-0.8), 0.2% (0.2-0.3), 0.1% (0.01-0.2), 0.3% (0.1-0.4), 0.2% (0.2-0.3), 0.5% (0.08-0.8), 0.1% (0.02-0.2), and 0.1% (0.06-0.3), respectively. Allergy to cow's milk and egg was more common among younger children, while allergy to peanut, tree nuts, fish, and shellfish was more common among the older ones. There were insufficient data to compare the estimates of soy and wheat allergy between the age groups. Allergy to most foods, except soy and peanut, appeared to be more common in Northern Europe. In summary, the lifetime self-reported prevalence of allergy to common foods in Europe ranged from 0.1 to 6.0%. The heterogeneity between studies was high, and participation rates varied across studies reaching as low as <20% in some studies. Standardizing the methods of assessment of food allergies and initiating strategies to increase participation will advance this evidence base.

The natural history of cow's milk allergy in north-eastern Poland

PURPOSE

The rate of cow's milk allergy diminishes with age. There is not enough information concerning geographical trends in persistent cow's milk allergy in children. The objective of the study was to evaluate the prevalence of persistent cow's milk allergy in children previously diagnosed with IgE-mediated cow's milk allergy (CMA).

MATERIAL/METHODS

Diagnosis of cow's milk allergy was established by a medical history of symptoms associated with exposure to cow's milk, positive skin prick tests with cow's milk, the presence of milk-specific IgE, and by a positive double- or single-blind placebo-controlled food challenge with milk confirmed by a positive open-controlled milk challenge. A second oral challenge was performed after at least one year of a milk-free diet and children with a positive oral milk rechallenge were diagnosed as having a persistent CMA.

RESULTS

Two hundred ninety-one children, 2-14 years of age (mean 5.30±3.16 years, 95% CI, 5.02-5.62 years) completed the study. Persistent CMA was diagnosed in 79 patients (27.1%). Two hundred twelve children (72.9%) outgrew their allergy to cow's milk at a mean age of 5 years after an average time of 16.4±0.8 months on an elimination diet. Eighty percent of children below 3 years of age became milk tolerant. Milk-specific IgE (p=0.018) and history of paternal bronchial asthma and/or rhinitis (p=0.020) were associated with persistence of cow's milk allergy in regression analysis.

CONCLUSIONS

An age above 3 years, as well as features of atopy, individual and familial, may be associated with a risk of delayed tolerance to milk in children.

The epidemiology of food allergy in Europe: a systematic review and meta-analysis

Food allergy (FA) is an important atopic disease although its precise burden is unclear. This systematic review aimed to provide recent, up-to-date data on the incidence, prevalence, time trends, and risk and prognostic factors for FA in Europe. We searched four electronic databases, covering studies published from 1 January 2000 to 30 September 2012. Two independent reviewers appraised the studies and qualified the risk of bias using the Critical Appraisal Skills Programme tool. Seventy-five eligible articles (comprising 56 primary studies) were included in a narrative synthesis, and 30 studies in a random-effects meta-analysis. Most of the studies were graded as at moderate risk of bias. The pooled lifetime and point prevalence of self-reported FA were 17.3% (95% CI: 17.0-17.6) and 5.9% (95% CI: 5.7-6.1), respectively. The point prevalence of sensitization to ≥1 food as assessed by specific IgE was 10.1% (95% CI: 9.4-10.8) and skin prick test 2.7% (95% CI: 2.4-3.0), food challenge positivity 0.9% (95% CI: 0.8-1.1). While the incidence of FA appeared stable over time, there was some evidence that the prevalence may be increasing. There were no consistent risk or prognostic factors for the development or resolution of FA identified, but sex, age, country of residence, familial atopic history, and the presence of other allergic diseases seem to be important. Food allergy is a significant clinical problem in Europe. The evidence base in this area would benefit from additional studies using standardized, rigorous methodology; data are particularly required from Eastern and Southern Europe.

Factors associated with reported food allergy tolerance among US children

BACKGROUND

Limited studies exist on predictors of food allergy tolerance.

OBJECTIVE

To describe factors associated with tolerance to 9 common food allergens based on caregiver report in a nationally representative survey.

METHODS

Data from children with current and outgrown food allergies were identified for analysis from a randomized, cross-sectional survey administered in US households with children from June 2009 through February 2010. Allergies were analyzed based on type of allergy, age at which allergies were outgrown, and reaction history. Adjusted models were formulated to examine the association of child and food allergy characteristics with odds of reporting an allergy as being outgrown.

RESULTS

Of 40,104 children surveyed, 1,245 cases of outgrown food allergy were identified. The frequency of tolerance in children with food allergy was 26.6% at a mean age of 5.4 years. Children with milk (41.1%), egg (40.2%), or soy (35.7%) allergy had significantly higher frequencies of tolerance, whereas children with shellfish (13.0%), tree nut (14.3%), and peanut (15.6%) allergies had significantly lower frequencies (P < .05). Factors significantly associated with a report of outgrowing an allergy included a mild to moderate reaction history, being allergic to only 1 food, eczema as the sole allergy symptom, and white compared with black race (P < .05). Probability of tolerance also was significantly higher at younger ages of first reaction and decreased for first reactions occurring later in life, irrespective of allergen, severity, or presentation (P < .05).

CONCLUSION

Multiple factors were associated with a report of outgrowing an allergy. Understanding factors associated with outgrowing an allergy can improve disease management and counseling.

Epidemiology of childhood food allergy

Food allergy is a public health problem that affects nearly 6 million children in the United States. The extent to which children, families, and communities live with food allergies varies as much as the range of clinical symptoms associated with the disease itself. Food allergy is defined as the reproducible adverse event that elicits a pathologic immunoglobulin E (IgE)-mediated or non-IgE-mediated reaction. Once an allergic child ingests a specific food allergen, the reaction can result in clinical symptoms ranging from mild hives to life-threatening anaphylaxis.Not surprisingly, food allergies have been shown to limit social interactions and impair children's quality of life due to the ubiquity of food where children live, learn, and play. To ensure the safety of our children, the development of sound policy, clinical practice, and health programs must be informed by current research characterizing childhood food allergy at the population level. To set the stage for understanding the current evidence base, this article reviews: 1) epidemiology of childhood food allergy; 2) severity of symptoms; 3) geographic distribution of childhood food allergy; 4) tolerance; 5) economic impact of childhood food allergy; and 6) future directions in childhood food allergy epidemiological research.

Predicting positive food challenges in children sensitised to peanuts/tree nuts

BACKGROUND

Children with atopic diseases in early life are frequently found with positive IgE tests to peanuts/tree nuts without a history of previous ingestion. We aimed to identify risk factors for reactions to nuts at first introduction.

METHODS

A retrospective case-note and database analysis was performed. Recruitment criteria were: patients aged 3-16 yr who had a standardized food challenge to peanut and/or tree nuts due to sensitisation to the peanut/tree nut (positive spIgE or SPT) without previous consumption. A detailed assessment was performed of factors relating to food challenge outcome with univariate and multivariate logistic regression analysis.

RESULTS

There were 98 food challenges (47 peanut, 51 tree nut) with 29 positive, 67 negative and 2 inconclusive outcomes. A positive maternal history of allergy and a specific IgE >5 kU/l were strongly associated with a significantly increased risk of a positive food challenge (OR 3.73; 95% CI 1.31-10.59; p = 0.013 and OR 3.35; 95% CI 1.23-9.11; p = 0.007, respectively). Adjusting for age, a three year-old with these criteria has a 67% probability of a positive challenge. There was no significant association between types of peanut/tree nut, other food allergies, atopic conditions or severity of previous food reactions and positive challenges.

CONCLUSIONS

We have demonstrated an association between the presence of maternal atopic history and a specific IgE >5 kU/l, with a significant increase in the likelihood of a positive food challenge. Although requiring further prospective validation these easily identifiable components should be considered when deciding the need for a challenge.

ICON: food allergy

Food allergies can result in life-threatening reactions and diminish quality of life. In the last several decades, the prevalence of food allergies has increased in several regions throughout the world. Although more than 170 foods have been identified as being potentially allergenic, a minority of these foods cause the majority of reactions, and common food allergens vary between geographic regions. Treatment of food allergy involves strict avoidance of the trigger food. Medications manage symptoms of disease, but currently, there is no cure for food allergy. In light of the increasing burden of allergic diseases, the American Academy of Allergy, Asthma & Immunology; European Academy of Allergy and Clinical Immunology; World Allergy Organization; and American College of Allergy, Asthma & Immunology have come together to increase the communication of information about allergies and asthma at a global level. Within the framework of this collaboration, termed the International Collaboration in Asthma, Allergy and Immunology, a series of consensus documents called International Consensus ON (ICON) are being developed to serve as an important resource and support physicians in managing different allergic diseases. An author group was formed to describe the natural history, prevalence, diagnosis, and treatment of food allergies in the context of the global community.