medical mondays: food allergies

Hello my lovelies, welcome back to Medical Mondays! 

You know the drill.

A helpful hint for this post: When I refer to the most common allergy-inducing foods, I am talking about cow's milk, soy, eggs, fish, nuts, and wheat.

Enjoy!

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At the Office

I first want to narrow the field a little bit. Of course anyone of any age can suffer from a food allergy, but in this post I am mostly covering the food allergies that could present themselves in the first year of life. That age range seems to be the focus of most questions I receive from parents.

Food allergies are a hot topic right now. One of the most significant recent developments surrounds our thinking about the relation of developing allergies with the timing of starting solids. This is a topic that several of you have asked about, and one that I talk with parents about frequently. So here's the deal: We used to think that delaying exposure of any kind to the most common allergy-inducing foods would reduce a kid's risk of developing an allergy to that food. Now we know that is not true. There is also no good evidence that mom avoiding foods during pregnancy or while breastfeeding will keep the kid from developing an allergy. And there is also no good evidence for significantly delaying the introduction of these foods themselves into a baby's diet. AND there is no good evidence for delaying solid foods in general past 4-6 months in order to decrease a baby's risk of food allergies.

Let be clear though: there are a LOT of new studies being done about this topic. I get overwhelmed sometimes with all the new research and the new recommendations. What I feel comfortable telling my patients at this point is: if your baby is at low-risk for developing a food allergy (ie, mom and dad don't have any, and baby hasn't shown us any signs of allergic factors like eczema or asthma), it's probably ok to start introducing some of these foods within a few months of starting solids. I tell parents to wait a few days between introducing these foods, and to watch carefully for any sign of reaction (which will mostly likely be a rash, diarrhea, or vomiting). It is very important to talk to your pediatrician about specific recommendations about when it's ok to introduce these foods to your kid.

I have had this conversation several times with families this past week. Two of the families I'm thinking of were very similar: both had a two or three year old, and a six or nine month old. They are a perfect illustration of how much has changed just in the past year or two with regards to early feeding recommendations. With both these families, I had to talk through what they would have done for their toddler, and how it is now different for their baby. This kind of bums me out, because I keep thinking that I will have the hang of this parenting thing by the next baby, but you KNOW the big dogs will change things up in the next year or two and everything will be different!

I did a post about starting solids and a follow-up post about solids too.

Now it's time for our vocabulary lesson:

• A person is considered allergic to a food if an immune response occurs after consuming it. The immune system is complicated. I don't want to get too complicated in this definition.

• A person is considered intolerant to a food if they have a non-immune response after consuming it. They could get an upset tummy after having ice cream, but it's not because their immune system is going wacky. The upset tummy could be because they lack enough lactase, which is what we need to break down the sugar in milk. The problem isn't that their body reacts in an immune-modulated way, but because they just don't have the right equipment for that particular food.
• This leads to another point: a food intolerance can be dose dependent, meaning the severity of the reaction can be based upon how much of the food you consume. For example, if you are intolerant to dairy, you might be able to have some butter on your pancakes and be ok, but eating four slices of pizza with a glass of milk sends you to the you-know-where.

OK, so in the baby population, the most common allergy I see is to cow's milk. Often this is fed to a baby through mom's milk if she consumes dairy, or through dairy-based formulas. Usually the allergy manifests by a rash (eczema) or tummy symptoms like excessive spitting up or reflux, diarrhea, or bloody stools. Sometimes the reaction is so severe that the baby even has trouble gaining weight because calories and nutrients cannot be absorbed properly.

This may be a good time to clear up a common misperception: when baby's have a milk allergy, they are allergic to the cow's milk protein. This is very different from being lactose intolerant, which is, first of all, an intolerance, and secondly, a reaction to the cow's milk sugar. This intolerance often doesn't develop until later, as our ancestors did not consume milk after early childhood, so their need to develop the enzyme lactase stopped. Thanks, ancestors.

The good news about a milk protein allergy is that a lot of babies outgrow it. Kids with egg allergy often outgrow that by early elementary school. However, most kids with a peanut allergy are stuck with it.

In the textbook

The medical side of this discussion would involve some explanation about the allergic processes in our body. I'm not in the mood for that today. Let's move on.

At our house

Jonathan has inherited some good and not-so-good genes from his parents. Neither Jon nor I have major food allergies, but oooooh the intolerances abound!

I did not eliminate any foods from my diet during pregnancy and in the early days of nursing. However, around four months, we started suspecting that Jonathan was sensitive to dairy in my diet. He had always been a spit-up kid, but on days that I was home from work he seemed to spit up a lot more. I thought maybe it had something to do with the large amounts of milk I consumed when I was at home (seriously, it is abnormal how much I love milk). So I cut out dairy, and he seemed to improve on the spit-up front. Some days he would still spit-up, but overall the pattern correlated to my dairy intake. For several months I was pretty strict with my diet, but would occasionally have a piece of pizza or something. By about eight months, I was back to consuming dairy and he was consuming cheese and yogurt and was doing fine.

Our story is a good example of an intolerance and how to diagnose it. We never brought Jonathan to an allergist to have him tested for a reaction to milk. Those tests probably would have been negative anyway. We just had a strong suspicion because of his pattern, so we tried something and it worked. There ya go. Probably an intolerance. And it makes sense, too, because it seemed to be dose related (i.e., I could have a slice of pizza, but couldn't down four glasses of milk in a day). I still wonder how he will do when he's consuming straight cow's milk in a couple months. I don't think we will go back to the spitting up, but poor little buddy has constipation issues in a major way, and cow's milk probably won't be much help with that. :( (I am not prepared to talk about constipation on Medical Mondays because I like the "At our house" section to be helpful, and I have no idea how to fix my child's constipation. You can thank the holy spirit for making me divulge this vulnerable information.)

Other than the milk stuff, he has done well with wheat, eggs, peanut butter, and other forms of dairy. Since he is low-risk for food allergies, I've felt fine with introducing these things fairly early on in our solids adventure. I think by around nine months he had tried all these things.

My child loves yogurt.

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That's all I got mamas. Hope you learned something new! Questions, comments, stories, or concerns are WELCOMED :) Happy Monday!