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Food Hypersensitivity

Management of Food Allergies and Food-Related Anaphylaxis

Author/s: 
Edward G A Iglesia, Mildred Kwan, Yamini V Virkud, Onyinye I Iweala

Importance: An estimated 7.6% of children and 10.8% of adults have IgE-mediated food-protein allergies in the US. IgE-mediated food allergies may cause anaphylaxis and death. A delayed, IgE-mediated allergic response to the food-carbohydrate galactose-α-1,3-galactose (alpha-gal) in mammalian meat affects an estimated 96 000 to 450 000 individuals in the US and is currently a leading cause of food-related anaphylaxis in adults.

Observations: In the US, 9 foods account for more than 90% of IgE-mediated food allergies-crustacean shellfish, dairy, peanut, tree nuts, fin fish, egg, wheat, soy, and sesame. Peanut is the leading food-related cause of fatal and near-fatal anaphylaxis in the US, followed by tree nuts and shellfish. The fatality rate from anaphylaxis due to food in the US is estimated to be 0.04 per million per year. Alpha-gal syndrome, which is associated with tick bites, is a rising cause of IgE-mediated food anaphylaxis. The seroprevalence of sensitization to alpha-gal ranges from 20% to 31% in the southeastern US. Self-injectable epinephrine is the first-line treatment for food-related anaphylaxis. The cornerstone of IgE-food allergy management is avoidance of the culprit food allergen. There are emerging immunotherapies to desensitize to one or more foods, with one current US Food and Drug Administration-approved oral immunotherapy product for treatment of peanut allergy.

Conclusions and relevance: IgE-mediated food allergies, including delayed IgE-mediated allergic responses to red meat in alpha-gal syndrome, are common in the US, and may cause anaphylaxis and rarely, death. IgE-mediated anaphylaxis to food requires prompt treatment with epinephrine injection. Both food-protein allergy and alpha-gal syndrome management require avoiding allergenic foods, whereas alpha-gal syndrome also requires avoiding tick bites.

Keywords 
Alpha-Gal Syndrome Anaphylaxis Food Allergies Food Allergy nuts Shellfish

What Is Alpha-Gal Syndrome?

Author/s: 
Fatema Mollah, Mark A Zacharek, Mariel R Benjamin

Alpha-gal syndrome is a type of food allergy to mammalian (red) meat products.

Alpha-gal syndrome is associated with tick bites, most commonly from the Lone Star tick in the US, but also from different types of ticks in other areas of the world. During a bite, a tick injects a type of sugar molecule (galactose-alpha-1,3-galactose), also called alpha-gal, which leads to formation of an antibody. Because alpha-gal is present on cells of most mammals, including cows, pigs, lambs, and goats, when affected individuals eat these animal products, an allergic reaction may occur.

Keywords 
allergy and clinical immunology Patient Information diet red meat allergy Alpha-Gal Syndrome

Timing of Allergenic Food Introduction and Risk of Immunoglobulin E-Mediated Food Allergy: A Systematic Review and Meta-analysis

Author/s: 
Scarpone, R., Kimkool, P., Ierodiakonou, D., Leonardi-Bee, J., Garcia-Larsen, V., Perkin, M. R., Boyle, R. J.

Importance: Earlier egg and peanut introduction probably reduces risk of egg and peanut allergy, respectively, but it is uncertain whether food allergy as a whole can be prevented using earlier allergenic food introduction.

Objective: To investigate associations between timing of allergenic food introduction to the infant diet and risk of food allergy.

Data sources: In this systematic review and meta-analysis, Medline, Embase, and CENTRAL databases were searched for articles from database inception to December 29, 2022. Search terms included infant, randomized controlled trial, and terms for common allergenic foods and allergic outcomes.

Study selection: Randomized clinical trials evaluating age at allergenic food introduction (milk, egg, fish, shellfish, tree nuts, wheat, peanuts, and soya) during infancy and immunoglobulin E (IgE)-mediated food allergy from 1 to 5 years of age were included. Screening was conducted independently by multiple authors.

Data extraction and synthesis: The Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was used. Data were extracted in duplicate and synthesized using a random-effects model. The Grading of Recommendations, Assessment, Development, and Evaluation framework was used to assess certainty of evidence.

Main outcomes and measures: Primary outcomes were risk of IgE-mediated allergy to any food from 1 to 5 years of age and withdrawal from the intervention. Secondary outcomes included allergy to specific foods.

Results: Of 9283 titles screened, data were extracted from 23 eligible trials (56 articles, 13 794 randomized participants). There was moderate-certainty evidence from 4 trials (3295 participants) that introduction of multiple allergenic foods from 2 to 12 months of age (median age, 3-4 months) was associated with reduced risk of food allergy (risk ratio [RR], 0.49; 95% CI, 0.33-0.74; I2 = 49%). Absolute risk difference for a population with 5% incidence of food allergy was -26 cases (95% CI, -34 to -13 cases) per 1000 population. There was moderate-certainty evidence from 5 trials (4703 participants) that introduction of multiple allergenic foods from 2 to 12 months of age was associated with increased withdrawal from the intervention (RR, 2.29; 95% CI, 1.45-3.63; I2 = 89%). Absolute risk difference for a population with 20% withdrawal from the intervention was 258 cases (95% CI, 90-526 cases) per 1000 population. There was high-certainty evidence from 9 trials (4811 participants) that introduction of egg from 3 to 6 months of age was associated with reduced risk of egg allergy (RR, 0.60; 95% CI, 0.46-0.77; I2 = 0%) and high-certainty evidence from 4 trials (3796 participants) that introduction of peanut from 3 to 10 months of age was associated with reduced risk of peanut allergy (RR, 0.31; 95% CI, 0.19-0.51; I2 = 21%). Evidence for timing of introduction of cow's milk and risk of cow's milk allergy was very low certainty.

Conclusions and relevance: In this systematic review and meta-analysis, earlier introduction of multiple allergenic foods in the first year of life was associated with lower risk of developing food allergy but a high rate of withdrawal from the intervention. Further work is needed to develop allergenic food interventions that are safe and acceptable for infants and their families.

Keywords 
Shellfish nuts Food Allergies allergen introduction egg

Food Allergy Prevention: Early Versus Late Introduction of Food Allergens in Children

Author/s: 
Djossi, S. K., Khedr, A., Neupane, B., Proskuriakova, E., Jada, K., Mostafa, J. A.

The emergence of food allergies in children is crucial for various medical fields seeking a viable strategy for allergy prevention. The most well-recognized approach adopted by numerous health care and government institutions hinges on the delay in the introduction of food allergens, which supposedly protects infants from sensitization and decreases the possibility of allergy development. However, recent experimental findings indicate that the benefits of this approach might be overestimated, as early exposure to allergenic foods has been shown to yield more advantageous outcomes. Multiple investigations on the causes of allergic diseases report that avoiding food allergies might be related to early consumption of these allergens. Alternatively, delaying the contact with allergenic nourishments, explored in contemporary research, has been proven to result in a higher prevalence of allergies among children, originating such conditions as atopic diseases and extreme sensitization to foods. The current paper compares the two prominent strategies of allergenic food introduction, gathering the most pertinent modern evidence to distinguish whether exposure to food allergens should be delayed or advanced.

Keywords 
Food Allergy children Allergens Allergy Prevention

Infant pacifier sanitization and risk of challenge-proven food allergy: A cohort study

Author/s: 
Soriano, V.X., Koplin, J.J., Forrester, M., Peters, R.L., O'Hely, M., Dharmage, S.C., Wright, R., Ranaganathan, S., Burgner, D., Thompson, K., Dwyer, T., Vuilerman, P., Ponsonby, A.

Background: Environmental microbial exposure plays a role in immune system development and susceptibility to food allergy.

Objective: We sought to investigate whether infant pacifier use during the first postnatal year, with further consideration of sanitization, alters the risk of food allergy by age 1 year.

Methods: The birth cohort recruited pregnant mothers at under 28 weeks' gestation in southeast Australia, with 894 families followed up when infants turned 1 year. Infants were excluded if born under 32 weeks, with a serious illness, major congenital malformation, or genetic disease. Questionnaire data, collected at recruitment and infant ages 1, 6, and 12 months, included pacifier use and pacifier sanitization (defined as the joint exposure of a pacifier and cleaning methods). Challenge-proven food allergy was assessed at 12 months.

Results: Any pacifier use at 6 months was associated with food allergy (adjusted odds ratio, 1.94; 95% CI, 1.04-3.61), but not pacifier use at other ages. This overall association was driven by the joint exposure of pacifier-antiseptic use (adjusted odds ratio, 4.83; 95% CI, 1.10-21.18) compared with no pacifier use. Using pacifiers without antiseptic at 6 months was not associated with food allergy. Among pacifier users, antiseptic cleaning was still associated with food allergy (adjusted odds ratio, 3.56; 95% CI, 1.18-10.77) compared with no antiseptic use. Furthermore, persistent and repeated antiseptic use over the first 6 months was associated with higher food allergy risk (P = .029).

Conclusions: This is the first report of a pacifier-antiseptic combination being associated with a higher risk of subsequent food allergy. Future work should investigate underlying biological pathways.

Keywords: Pacifier; antiseptic; birth cohort; dummy; food allergy; microbial exposure; sanitization.

Keywords 
infant Pregnancy Pregnant Persons Mothers Allergic reactions Food Allergies
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