BACKGROUND

For egg allergy, dietary avoidance is the only currently approved treatment. We evaluated oral immunotherapy using egg-white powder for the treatment of children with egg allergy.

METHODS

In this double-blind, randomized, placebo-controlled study, 55 children, 5 to 11 years of age, with egg allergy received oral immunotherapy (40 children) or placebo (15). Initial dose-escalation, build-up, and maintenance phases were followed by an oral food challenge with egg-white powder at 10 months and at 22 months. Children who successfully passed the challenge at 22 months discontinued oral immunotherapy and avoided all egg consumption for 4 to 6 weeks. At 24 months, these children underwent an oral food challenge with egg-white powder and a cooked egg to test for sustained unresponsiveness. Children who passed this challenge at 24 months were placed on a diet with ad libitum egg consumption and were evaluated for continuation of sustained unresponsiveness at 30 months and 36 months.

RESULTS

After 10 months of therapy, none of the children who received placebo and 55% of those who received oral immunotherapy passed the oral food challenge and were considered to be desensitized; after 22 months, 75% of children in the oral-immunotherapy group were desensitized. In the oral-immunotherapy group, 28% (11 of 40 children) passed the oral food challenge at 24 months and were considered to have sustained unresponsiveness. At 30 months and 36 months, all children who had passed the oral food challenge at 24 months were consuming egg. Of the immune markers measured, small wheal diameters on skin-prick testing and increases in egg-specific IgG4 antibody levels were associated with passing the oral food challenge at 24 months.

CONCLUSIONS

These results show that oral immunotherapy can desensitize a high proportion of children with egg allergy and induce sustained unresponsiveness in a clinically significant subset. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT00461097.)

Data from many studies have suggested a rise in the prevalence of food allergies during the past 10 to 20 years. Currently, no curative treatments for food allergy exist, and there are no effective means of preventing the disease. Management of food allergy involves strict avoidance of the allergen in the patient's diet and treatment of symptoms as they arise. Because diagnosis and management of the disease can vary between clinical practice settings, the National Institute of Allergy and Infectious Diseases (NIAID) sponsored development of clinical guidelines for the diagnosis and management of food allergy. The guidelines establish consensus and consistency in definitions, diagnostic criteria, and management practices. They also provide concise recommendations on how to diagnose and manage food allergy and treat acute food allergy reactions. The original guidelines encompass practices relevant to patients of all ages, but food allergy presents unique and specific concerns for infants, children, and teenagers. To focus on those concerns, we describe here the guidelines most pertinent to the pediatric population.

Background

The majority (∼75%) of cow's milk-allergic children tolerate extensively heated-(baked-) milk products. Long-term effects of inclusion of dietary baked-milk have not been reported.

Objective

We report on the outcomes of children who incorporated baked-milk products into their diets.

Methods

Children evaluated for tolerance to baked-milk (muffin) underwent sequential food challenges to baked-cheese (pizza) followed by unheated-milk. Immunologic parameters were measured at challenge visits. The comparison group were matched to active subjects (using age, sex, and baseline milk-specific IgE) to evaluate the natural history of tolerance development.

Results

Over a median of 37 months (range 8-75 months), 88 children underwent challenges at varying intervals (range 6-54 months). Among 65 subjects initially tolerant to baked-milk, 39 (60%) now tolerate unheated-milk, 18 (28%) tolerate baked-milk/baked-cheese and 8 (12%) chose to avoid milk strictly. Among the baked-milk-reactive subgroup (n=23), 2 (9%) tolerate unheated-milk, 3 (13%) tolerate baked-milk/baked-cheese, while the majority (78%) avoid milk strictly. Subjects who were initially tolerant to baked-milk were 28 times more likely to become unheated-milk-tolerant compared to baked-milk-reactive subjects (P<.001). Subjects who incorporated dietary baked-milk were 16 times more likely than the comparison group to become unheated-milk-tolerant (P<.001). Median casein IgG4 levels in the baked-milk-tolerant group increased significantly (P<.001); median milk IgE values did not change significantly.

Conclusions

Tolerance of baked-milk is a marker of transient IgE-mediated cow's milk allergy whereas reactivity to baked-milk portends a more persistent phenotype. The addition of baked-milk to the diet of children tolerating such foods appears to accelerate development of unheated-milk tolerance compared to strict avoidance.

Clinical implications

Addition of dietary baked-milk is safe, convenient, and well-accepted by patients. Prescribing baked-milk products to milk-allergic children represents an important shift in the treatment paradigm for milk allergy.

Capsule summary

The majority of cow's milk-allergic children tolerate extensively baked-milk products, which is a marker of transient IgE-mediated cow's milk allergy. Dietary baked-milk appears to accelerate development of unheated-milk tolerance compared to strict avoidance.

Background

Peanut allergy is typically severe, life-long and prevalent.

Objective

To identify factors associated with peanut sensitization.

Methods

We evaluated 503 infants 3–15 months of age (mean, 9.4 months) with likely milk or egg allergy but no previous diagnosis of peanut allergy. A total of 308 had experienced an immediate allergic reaction to cow’s milk and/or egg and 204 had moderate to severe atopic dermatitis and a positive allergy test to milk and/or egg. A peanut IgE level of ≥ 5 kUA/L was considered likely indicative of peanut allergy.

Results

A total of 140 (27.8%) infants had PN-IgE levels ≥5 kUA/L. Multivariate analysis including clinical, laboratory and demographic variables showed frequent peanut consumption during pregnancy (OR 2.9, 95% CI 1.7–4.9, p < 0.001), IgE levels to milk (p = 0.001) and egg (p < 0.001), male sex (p = 0.02) and non-white race (p = 0.02) to be the primary factors associated with peanut IgE ≥5 kUA/L. Frequency of peanut consumption during pregnancy and breast feeding showed a dose-response association with peanut IgE ≥ 5 kUA/L, but only consumption during pregnancy was a significant predictor. Among 71 infants never breastfed, frequent consumption of peanut during pregnancy was strongly associated with peanut IgE ≥ 5 kUA/L (OR-4.99, 95% CI-1.69–14.74, p < 0.004).

Conclusions

In this cohort of infants with likely milk or egg allergy, maternal ingestion of peanut during pregnancy was strongly associated with a high level of peanut sensitization.

Background

Immune features of infants with food allergy have not been delineated.

Objectives

To explore basic mechanisms responsible for food allergy and identify biomarkers, e.g. prick skin tests (PST), food-specific IgE, and mononuclear cell responses in a cohort of infants with likely milk/egg allergy at increased risk of developing peanut allergy.

Methods

Infants aged 3–15 months were enrolled with a positive PST to milk or egg and either a corresponding convincing clinical history of allergy to milk or egg, or with moderate to severe atopic dermatitis (AD). Infants with known peanut allergy were excluded.

Results

Overall, 512 infants (67% males) were studied with 308 (60%) having a history of a clinical reaction. Skin tests and/or detectable food-specific IgE revealed sensitization as follows: milk-78%, egg-89% and peanut-69%. PST and food-specific IgE levels were discrepant for peanut: 15% IgE ≥ 0.35 kUA/L/PST- versus 8% PST+/IgE < 0.35, p = 0.001. Mononuclear cell allergen stimulation screening for CD25, CISH, FOXP3, GATA3, IL-10, IL-4, IFN-gamma and TBET expression using casein, egg white and peanut revealed that only allergen-induced IL-4 expression was significantly increased in those with clinical allergy to milk (compared to non-allergic) and in those sensitized to peanut, despite the absence of an increase in GATA-3 mRNA expression.

Conclusions

Infants with likely milk/egg allergy are at considerably high risk of having elevated peanut-specific IgE (potential allergy). Peanut-specific serum IgE was a more sensitive indicator of sensitization than PST. Allergen-specific IL-4 expression may be a marker of allergic risk. Absence of an increase in GATA-3 mRNA expression suggests that allergen-specific IL-4 may not be of T cell origin.

Background

Data about epinephrine utilization and biphasic reactions in childhood food-induced anaphylaxis during oral food challenges are scarce.

Objective

To determine the prevalence and risk factors of reactions requiring epinephrine and the rate of biphasic reactions during oral food challenges (OFCs) in children.

Methods

Reaction details of positive OFCs in children between 1999 and 2007 were collected using a computerized database. Selection of patients for OFCs was generally predicated on ≤50% likelihood of a positive challenge and a low likelihood of a severe reaction based on the clinical history, specific IgE levels, and skin prick tests (SPTs).

Results

A total of 436 of 1273 OFCs resulted in a reaction (34%). Epinephrine was administered in 50 challenges (11% of positive challenges, 3.9% overall); for egg (n=15, 16% of positive OFCs to egg), milk (n=14, 12%), peanut (n=10, 26%), tree nuts (n=4, 33%), soy (n=3, 7%), wheat (n=3, 9%), and fish (n=1, 9%). Reactions requiring epinephrine occurred in older children (median 7.9 vs. 5.8 years, P<0.001), and were more often caused by peanuts (P=0.006) when compared to reactions not treated with epinephrine. There was no difference in the gender, prevalence of asthma, history of anaphylaxis, specific IgE level, SPTs, or amount of food administered. Two doses of epinephrine were required in 3/50 patients (6%) reacting to wheat, cow’s milk, and pistachio. There was one (2%) biphasic reaction. No reaction resulted in life-threatening respiratory or cardiovascular compromise.

Conclusion

Older age and reactions to peanuts were risk factors for anaphylaxis during oral food challenges. Reactions requiring multiple doses of epinephrine and biphasic reactions were infrequent.

Background

The national prevalence and patterns of food allergy (FA) in the United States (US) are not well understood.

Objective

We developed nationally representative estimates of the prevalence of and demographic risk factors for FA, and investigated associations of FA with asthma, hay fever, and eczema.

Methods

8,203 participants in the National Health and Nutrition Examination Survey (NHANES) 2005–2006 had food-specific serum IgE measured to peanut, cow's milk, egg white, and shrimp. Food-specific IgE and age-based criteria were used to define Likely FA (LFA), Possible FA (PFA), and Unlikely FA (UFA), and to develop estimates of clinical FA. Self-reported data were used to evaluate demographic risk factors and associations with asthma and related conditions.

Results

In the US, the estimated prevalence of clinical FA was 2.5% (peanut 1.3%, milk 0.4%, egg 0.2%, shrimp 1.0%, not mutually exclusive). Risk of PFA/LFA was increased in non-Hispanic blacks (odds ratio (OR) 3.06; 95% confidence interval (CI) 2.14-4.36), males (1.87; 1.32-2.66), and children (2.04; 1.42-2.93). Study participants with doctor-diagnosed asthma (vs. no asthma) exhibited increased risk of all measures of food sensitization. Moreover, in those with LFA, the adjusted OR for current asthma (3.8; 1.5-10.7) and an emergency room (ER) visit for asthma in the past year (6.9; 2.4-19.7) were both notably increased.

Conclusion

Population-based serologic data on 4 foods indicate an estimated 2.5% of the US population has FA, and increased risk was found for blacks, males, and children. Additionally, FA could be an under-recognized risk factor for problematic asthma.

Background

Food allergy is estimated to affect 3–4% of adults in the US, but there are limited educational resources for primary care physicians. The goal of this study was to develop and pilot a food allergy educational resource based upon a needs survey of non-allergist healthcare providers.

Methods

A survey was undertaken to identify educational needs and preferences for providers, with a focus on physicians caring for adults and teenagers, including emergency medicine providers. The results of the survey were used to develop a teaching program that was subsequently piloted on primary care and emergency medicine physicians. Knowledge base tests and satisfaction surveys were administered to determine the effectiveness of the educational program.

Results

Eighty-two physicians (response rate, 65%) completed the needs assessment survey. Areas of deficiency and educational needs identified included: identification of potentially life-threatening food allergies, food allergy diagnosis, and education of patients about treatment (food avoidance and epinephrine use). Small group, on-site training was the most requested mode of education. A slide set and narrative were developed to address the identified needs. Twenty-six separately enrolled participants were administered the teaching set. Pre-post knowledge base scores increased from a mean of 38% correct to 64% correct (p < 0.001). Ability to correctly demonstrate the use of epinephrine self injectors increased significantly. Nearly all participants (>95%) indicated that the teaching module increased their comfort with recognition and management of food allergy.

Conclusion

Our pilot food allergy program, developed based upon needs assessments, showed strong participant satisfaction and educational value.