early exposure = less food allergies

[riomidwife]

Any other science geeks around? Wondering what you think of the Australian study that came out last year on timing of egg exposure, demonstrating a significant increase in egg allergy with exposure at a 12 months versus 4-6 months. Here's a link to the full text article: http://www.jacionline.org/article/S0091-6749%2810%2901173-5/fulltext and here is a press release blurb about it: http://newsroom.melbourne.edu/studio/ep-80

About 5-6% of the babies introduced to cooked egg at age four to six months developed an egg allergy.

While ~28% of babies who were not exposed until 12 months went on to develop an allergy.

I think the New Yorker also did a piece on this but I have not read it yet. Curious to hear your thoughts. I think it makes sense to delay exposure to certain foods that have not historically, as a species, been a part of our diet.... but I have wondered myself about the trend toward universally delaying exposure to all foods and whether this is really warranted.

[riomidwife]

no one has any thoughts? really?

the New Yorker piece is called The Peanut Puzzle, although I think you have to subscribe to read the online version.

[francesruben]

I recently noticed that Sally Fallon in her book 'Nourishing Traditions' recommends giving egg yolk at 4 months, but not the egg white as the protein is too difficult to digest. I've just discovered that my daughter has an egg allergy and we waited until she was 12 months on the advice of our doctor.

[matey]

I wonder about this too. DS showed allergic signs to egg before 6 months when touched by hands that had touched eggs, so it seemed to exist the whole time. However, we did delay intro of the peanut and with that intro came hives, swelling, and later, a positive blood test. Is it from delaying? Or is it more related to his sensitive make-up, being a preemie, eczema, reflux, dairy intolerance, double ear infections, skin rashes to everything. He is allergic to egg but like I said, that was from early on. He is allergic to penicillin, but that is certainly not due to lack of exposure after all those ear infections. The peanut though. I can' t help but wonder but then I look at his little list of sensitives and think this is just the way he is, regardless of introduction.

[ASusan]

We're a part of the 12%. DS reacted to egg visibly (hives on cheeks) the second time he had egg, at about 6-7 mos. Tested positive at 9 mos.

Was the Australian study randomized? or did it just measure timing and compare outcomes? Because it sure seems as if someone who might suspect a food allergy might delay introduction, and then a large number of those WOULD go on to demonstrate an allergy.

[riomidwife]

It was retrospective, so not randomized.

Below is a brief:

Background

Infant feeding guidelines have long recommended delaying introduction of solids and allergenic foods to prevent allergy in high-risk infants, despite a paucity of evidence.

Objective

We aimed to determine whether confirmed egg allergy in 12-month-old infants is associated with (1) duration of breast-feeding and (2) ages of introducing egg and solids.

Methods

In a population-based cross-sectional study (HealthNuts) parents reported on infant feeding and potential confounding factors before skin prick testing for egg white. Egg-sensitized infants were then offered an egg oral food challenge. Multiple logistic regression was used to investigate associations between diet and egg allergy adjusted for possible confounding factors.

Results

A total of 2589 infants (73% response) participated. Compared with introduction at 4 to 6 months, introducing egg into the diet later was associated with higher risks of egg allergy (adjusted odds ratios [ORs], 1.6 [95% CI, 1.0-2.6] and 3.4 [95% CI, 1.8-6.5] for introduction at 10-12 and after 12 months, respectively). These findings persisted even in children without risk factors (OR, 3.3 [95% CI, 1.1-9.9]; 10-12 months). At age 4 to 6 months, first exposure as cooked egg reduced the risk of egg allergy compared with first exposure as egg in baked goods (OR, 0.2 [95% CI, 0.06-0.71]). Duration of breast-feeding and age at introduction of solids were not associated with egg allergy.

Conclusions

Introduction of cooked egg at 4 to 6 months of age might protect against egg allergy. Changes in infant feeding guidelines could have a significant effect on childhood egg allergy and possibly food allergy more generally.