Preventing the Development of Allergies

This article appeared one year ago. I was interviewed on our local Fox news station about it. I thought that I reviewed the paper for this site. That either didn’t happen, is coded as a secret, exists as a draft, or got lost. I do think that the messages in that article are valuable and worth a review for our readers. There has been recent interest in this topic and I am anticipating another interview in the near future for a website that will link to this. What follows is a more detailed presentation of the article and my review of it.

Title Primary Prevention of Allergic Disease through Nutritional Interventions

Purpose– to introduce the concept of primary prevention through the infant’s diet

Authors- David Fleischer, Jonathon Spergel, Amal Assa`ad, and Jacqueline Pongracic

Journal- J Allergy and Clinical Immunology: In Practice 2013;1:29-36.

Background

                Most of the time we take care of established food allergy problems. We do not have any tools to predict a food allergy reliably. We sort through symptoms and cause-effect relationships to discover what foods are relevant. Imagine how exciting it would be to prevent food allergy before it presented. This is the basic idea of this article- thoughts, reviews, and recommendations for prevention of allergy via what we feed to our babies.

                This work focuses on the infant who is at a high risk for developing allergy. The recommendations are not meant for the ‘no/low-risk’ infant. The definition of high risk was intentionally broad in hopes of including as many children as possible. The infant at high risk for developing allergy has one or more first degree relatives with allergy- that would be a sibling or a parent and not distant cousins.

                As stated in the introduction of the paper, this document was developed as a resource for primary caretakers, allergists, and other specialists. The document is divided in the following parts;

                Maternal Dietary Restrictions

                Breast Feeding

                Use of infant formulas

                Timing of food introductions on the development of allergic disease

The paper included a review of the literature- what we know from good studies on these issues. It looked at references available as of August 2012.

It is important to note that the recommendations are not for children who already have developed a food allergy.

By the way- the three types of prevention in health care;

  1. Primary prevention- protect a child from developing a condition- stop it before it starts
  2. Secondary prevention- the condition has been established, this type of prevention slows it down or halts progression to long-term problems
  3. Tertiary prevention- working to control long term consequences and complications of the condition

This focuses on primary prevention in the infant at risk for developing allergy.

Maternal Avoidance of Highly Allergenic Foods for Primary Prevention of Allergic Disease in the Children.

Pregnancy

  • Avoidance of milk and egg has NO EFFECT
  • Peanut may be an issue (ingestion >2 times per week leads to increased risk of sensitization-reviewers note- sensitization refers to a positive allergy test only, there may not be any history of exposure or reactions)
  •  >1 time per week peanut ingestion lead to decreased chance of asthma (a good outcome)
  • A systematic review of animal and human work- DID NOT PROVIDE ANY CLEAR EVIDENCE THAT MATERNAL EXPOSURE OR AVOIDANCE OF PEANUTS HAD ANY EFFECT ON THE LATER DEVELOPMENT OF PEANUT SENSITIZATION OR ALLERGY.

Reviewer’s note– For the pregnant mother- she does not need to avoid egg or milk to prevent allergy in the child.

Peanut exposure has a mixed bag of conclusions- if she eats peanuts there may be a positive peanut test in the child per one study. There may also be less asthma in the child if she eats peanuts. The evidence for peanut is not at all clear. You may have to make your own decision on peanut ingestion.

Breast Feeding

  • The information out there is CONFLICTING. Bottom line- there is no significant benefit for the child when mother avoids highly allergenic foods during breast feeding.
  • One study found that there was a possible decrease in atopic dermatitis (a form of eczema) during the first two years of life, but that difference was gone after age 2 years.

Overall Recommendations for Mothers

  • Maternal avoidance of egg and milk during pregnancy– NOT RECOMMENDED
  • Maternal avoidance of peanut during pregnancy-  NO RECOMMENDATION ON THIS TOPIC
  • Maternal avoidance of highly allergenic foods during breast feeding- NOT RECOMMENDED

Exclusive Breast Feeding and specific allergic conditions-

Atopic Dermatitis

  • Exclusive breast feeding for 3 months deceases incidence of atopic dermatitis (however the power of this finding was dependent upon a controversial study, when that study was removed from the evaluation, there was no effect)
  • Beyond 3 months- conflicting reports on the impact of exclusive breast feeding

Asthma

  • Exclusive breast feeding for 3-4 months decreased cold-associated wheezing episodes up to 4 years of age.
  • Wheezing after age 6 years – the association with breast feeding is unclear
  • Suggestion that exclusive breast feeding may increase asthma risk after 14 years of age

Food Allergy

  • Exclusive breast feeding for >4 months decreased the risk of cow’s milk allergy (not food allergy in general just cow’s milk allergy)
  • Insufficient evidence to draw more general conclusions- no clear benefit in unselected populations.

Nasal Allergy

  • A borderline significant protective effect was found in one large analysis when breast feeding went on for 3 months.
  • Recent work found a reduced risk of nasal allergy with breast feeding, but many of these studies were not the best (term optimal is used).
  • There is a need to study this question- with better methods and longer time frames of observation

 

Summary Statements on Exclusive Breast Feeding

Exclusive breast feeding for at least 4-6 months will;

  • decrease the occurrence of atopic dermatitis
  • decrease wheezing episodes
  • decrease occurrence of cow’s milk allergy

Exclusive breast feeding will not make any difference for general/overall food allergy in the first 2 years of life.

The effect of on nasal allergy is not clear.

 

Infant Formula Selections for the Primary Prevention of Allergic Disease in Children

Cow’s Milk formula versus partial whey hydrolysate formula (pHF) (Gerber Good Start is an example of this type of formula)

  •  pHF have a preventative effect on atopic disease and cow’s milk protein allergy

pHFs versus extensive casein or extensive whey hydrolysate formulas (eHF) (Nutramigen, Pregestimil, and Alimentum are examples)

  • No significant difference between pHF and eHF in developing infant allergic diseases
  • May help decrease the risk of developing atopic dermatitis, but no effect on asthma and food allergy development.
  • More and better studies are needed

Soy formula versus other formulas; amino-acid based elemental formulas

  • There is no advantage using soy formula
  • Studies on the amino acid formulas are not available

Summary Statement Regarding Infant Formulas

  • No support for the use of these formulas over breast feeding to prevent atopic disease, except for those infants at increased risk who cannot be exclusively breast fed the first 4-6 months of life where a hydrolyzed formula offers an advantage to prevent allergic disease and cow’s milk allergy.
  • There is no substantial evidence for the use of soy formula to prevent atopic disease
  • More studies are needed with the amino acid formulas.

Introduction of Complementary Foods for Primary Prevention of Allergic Disease in Children

You have to be aware of the current guidance for infant feeding. The American Academy of Pediatrics (AAP) recommendations from 2000 advised delaying the introduction of highly allergenic foods to infants at high risk for allergic disease to prevent the development of future allergy;

                                Milk- 1 year

                                Egg- 2 years

                                Peanut, Tree Nuts, and Fish- 3 years

In the 10 years that followed these recommendations, the incidence and prevalence of food allergy and allergic conditions in general have increased significantly. Reviewer’s note- that begs the question as to whether or not this was the correct path to take.

During this increase in food allergy, the AAP’s Committee on Nutrition and the Section of Allergy and Immunology published in 2008 their findings that there was no convincing evidence for the delaying of specific highly allergenic foods. This opinion was shared by many other major professional societies throughout the world. This report however, gave no guidance as to how to approach the task of introducing of these foods. This report attempts to fill that void.

What follows are general guidelines and suggestions as to what to tell parents/patients when asked how to introduce these highly allergenic foods.

Newer information suggest that the delay of the introduction of solid food may increase the risk of food allergy or eczema and that the early introduction of allergenic foods may prevent food allergy.

  • Delaying cereal after 6 months did not protect but may have increased the risk of wheat allergy.
  • Cow’s milk in small amounts is safe prior to age 1 year (in baked goods, cheese, and yogurt) was safe. Early exposure may prevent developing milk allergy.
  • It may be beneficial to introduce egg at an early age in small amounts in baked goods or in a cooked egg form. 4-6 months seemed to be the age at which introduction of egg led to a lower risk of developing an egg allergy.
  • Early peanut exposure may prevent peanut allergy- as peanut butter between 6-12 months of life. Exception- a child who has a sibling with peanut allergy (seven-fold risk of peanut allergy)
  • Fish exposure prior to age 9 months decreased the risk of eczema at age one year.
  • There are no studies on the early introduction of soy or shellfish- do not feel that this needs to be delayed.

Summary

  • There is evidence that the introduction of highly allergenic food can occur earlier in the child’s diet as complementary foods.
  • As to whether early introduction of the highly allergenic foods proves to truly prevent individual food allergies remains to be seen. So far we have observational studies on this topic no interventional studies as yet.

This next part of the article was very well done. It went over a number of items that apply to all infants.

General Advice for Complementary Food Introduction for all Children regardless of Predisposition to Develop Allergic Disease.

  1. First introduction of single ingredient food- 4-6 months with one new food every 3-5 days
  2. These single ingredient complementary foods include
    • Rice or oat cereal
    • Yellow/orange vegetables
    • Fruits
    • Green vegetables
    • Followed by age-appropriate staged foods with meats
    • Acidic fruits will cause perioral rashes or hives due to irritation from the acid on the skin and from histamine releasing chemicals in the fruit. They do not usually result in a serious systemic reaction- DO NOT Delay the introduction of these foods. (Reviewer’s note- I see many children for a consideration of food allergy due to perioral rashes. This can be a normal consequence of wearing the food. The child should eat and not wear these foods. When they wear them they will have a rash.)
    • Do not start with the highly allergenic foods. Once a few of the other complementary foods are tolerated, then the highly allergenic ones may be introduced.
    • Avoid whole cow’s milk until age one (specifically jug/carton/dairy case milk- due to kidney issues) but Cow’s milk based infant formulas and other cow’s milk based products such as cheese and yogurt are safe prior to age one.
    • Whole peanuts and tree nuts have an aspiration risk and should be avoided, however peanut and nut butters can be given.

How to introduce the highly allergenic foods?

  • Give the initial taste of one of these foods at home- not at daycare or at a restaurant.
  • Do note and be advised that with some foods, peanut as a prime example, most reaction occur to what was thought to be the first exposure to that food.
  • If there is no reaction, the food can be introduced in gradually increasing amounts.
  • Introduction of other new foods should occur at one new food every 3-5 days.

When to seek out the help of an allergist?

  • Atopic dermatitis that is moderate-to-severe despite optimal treatment or when there is a history of an immediate reaction to a food. In this situation the less allergenic foods may still be safe to introduce, delaying the highly allergenic foods until evaluated by the specialist is recommended.
  • Children with one documented food allergy may have other food allergies, a referral is recommended.
  • If a blood test is positive for a food that has not been given to the child, a referral to an allergist who has experience in interpreting the blood test results and doing a food challenge to see if the results are relevant is recommended. This helps to prevent the elimination of unnecessary food removal from the diet. Reviewer’s comment- this is one of the most common reasons for a new patient visit. Blood studies as panels were performed and results indicated ‘high’ levels of antibody. This website is replete with commentary on the use of allergy panels).
  • If the serologic tests are negative despite a good clinical history of a reaction with exposure, a visit to the allergist for skin testing and a food challenge should be considered rather than having the family do this at home.
  •  The child who has a sibling with a peanut allergy has a 7% risk of also being peanut allergic. A peanut evaluation with a possible food challenge may be performed. The family needs to know that fatal reactions to peanut have not been reported on the first exposure and that the risks of introducing peanut at home in infancy are low. (Reviewer’s comment- I found this last statement very interesting and re-assuring).

Summary

  • Complementary foods can be introduced between 4-6 months of age
  • The highly allergenic foods can be given as complementary foods once a few complementary foods have been tolerated. This should be done at home.
  • There are situations when an allergist should be consulted; poorly controlled severe atopic dermatitis despite treatment or has a reliable history of an immediate reaction to a food.

 

Reviewer’s Comments- I applaud the authors for their work. They reviewed the literature and they are challenging our current precepts on food allergy. They point out that prior recommendations may not have had a significant amount of solid evidence to support them. There is also the possibility that the recommendations may be part of the reason for more food allergy issues in children.

There may be a window of opportunity that exists between the ages of 4-6 months where the introduction of highly allergenic food is met with the allergic tolerance.

There were a few concerns/questions to raise;

  1. I do not see an endorsement for this work. It appeared in a supplemental journal to the acclaimed Journal of Allergy and Clinical Immunology and the ‘In Practice’ version. I am used to seeing something like this as a reflection of the work done by a Task Force or committee. It is a set of recommendations by a group of authors that come from very prestigious academic centers. These are not NIH sponsored/endorsed guidelines and they are not AAP sponsored/supported/endorsed guidelines. This is a good review of the work and an exciting new look at a primary prevention. The paper also tells us where we need more work.
  2. Specifics of the plans are still lacking- the ‘How to… .’ section needs more information. Concerns- what is considered a taste? How long do you wait until the next exposure? How much should be in the next exposure? What is the time frame for escalation to a full exposure and what would that be? Once the child tolerates the food, how often do they need to be exposed to it, how many times per week?
  3. This is for the child at risk for allergy, not for a child who already has declared allergy.
  4. The definition of the ‘at risk’ for allergy child is a concern and was chosen to be loose and less restrictive.

Positives

  1. Finally a fresh look and approach to allergies-refreshing and gutsy.
  2. Items that need to be emphasized
    • Prior recommendations were made without much evidence  to support them
    • Fatal food reactions do not occur with the first exposure- I was surprised by this
    • Fruits- they are known to cause rashes around the mouth. This is not allergy and is no reason to not give the fruit.
    • There is no evidence to support many of the recommendations that are made especially during pregnancy and breast feeding. Peanut may be the exception.
    • The role of the allergist
    • The point of NOT DOING ROUTINE BLOOD STUDIES for food allergy screening via panels. Refer to the allergist first.
    • An allergy evaluation for atopic dermatitis is recommended for moderate to severe children who are not controlled on a therapeutic program.
    • The allergy referral should offer the opportunity for appropriate diagnostic studies and for doing a food challenge.

This article is a valuable contribution to the world of food allergy. It dispels unconfirmed notions, it identifies areas where there is no evidence for past guidance, and it identifies future areas of investigation to help make a difference in the public health problem of food allergy.

Parts of this evaluation will appear on another website. The writer is doing a review on this topic.
FEL 1/15/2014

January 17, 2014 · fleickly · No Comments
Tags: ,  · Posted in: Allergies, Developing Allergy, Food Allergies, Interesting articles, Pediatric Allergy, Preventing Allergy, Uncategorized

Leave a Reply

You must be logged in to post a comment.