Food Allergy Living Blog Tagged Results

In food allergy circles, we usually think of symptoms and side effects as results of food allergies, not the other way around. In most cases that’s true. Science has shown a strong link between food allergy and atopic dermatitis, a form of eczema. Last month Dr. Jon Hanifin, a respected dermatologist, gave a talk to colleagues discussing the link between atopic dermatitis and food allergies. The research he presented suggests that for some patients it may actually be atopic dermatitis that comes first and acts as a precursor to food allergies.

Atopic dermatitis is often one of the first signs that a parent or caregiver notices in their child which helps lead to the diagnosis of food allergy. As Dr. Hanifin explained, about 6-10% of children are diagnosed with atopic dermatitis, and of those about a third will be diagnosed with a food allergy. Which begs the question: If parents notice signs of atopic dermatitis first, and an allergy diagnosis comes later, couldn’t atopic dermatitis be causing some instances of food allergy?

What We Know:

-In cases of food allergy, offending foods cause reactions in the body which involve the immune system

-Immunoglobulin E antibodies (IgE) are immune substances which are normally in our bodies at low levels, but are higher with food allergy

-Allergy symptoms often involve the skin (including our digestive tract, which is like an inside skin), an important barrier that keeps most outside “things” from getting inside

-One factor of atopic dermatitis is “holes” in the barrier our skin provides

What Dr. Hanifin Proposed:

In the past it was assumed that food allergies came first, causing both high IgE levels and atopic dermatitis. Dr. Hanifin suggested that in some patients atopic dermatitis is caused by “gaps” in the skin (likely due to genetics), which means that foreign substances can enter the skin and cause adverse reactions. He thinks it may be proteins that get through these gaps which allows the body to become sensitive to certain foods, leading to a food allergy.

What does all of this mean? The biggest message here is that patients with atopic dermatitis, especially those under five years, should be tested for food allergies. While avoiding food allergens may not help improve atopic dermatitis, it could certainly prevent or improve other serious side effects of allergies. The second message is that more research needs to be done into the causes of atopic dermatitis and its relationship to food allergies. Any research that leads to better health, through reducing instances of atopic dermatitis and/or food allergies, is good research! Tell us about your experience: Was atopic dermatitis the first sign that you saw of your child’s food allergy?

- Rob

FPIES, or food protein induced enterocolitis syndrome, is a condition that I’ve been hearing about more and more lately. It is not particularly well-known, so I thought we could cover some of the basics in today’s blog.

What is FPIES?

FPIES is a disease that typically affects infants and young children. While it can mimic food allergies, the difference with FPIES is that it is a non-IgE mediated immune reaction in the gastrointestinal (GI) system to one or more specific foods. This means that the IgE antibodies associated with other food allergies are not involved in an FPIES reaction.

Cow’s milk and soy are the most common FPIES triggers, but ANY foods can cause an FPIES reaction (even ones that aren’t typically considered to be allergens like rice and oats).

Common Symptoms of FPIES

Most FPIES reactions happen when a child is very young – just a few weeks or months old. Often it happens when the first formulas or solid foods are introduced (breastmilk doesn’t usually cause an FPIES reaction, even if the mother has eaten a trigger food).

Each child is different, but the most common symptoms of FPIES involve the GI tract and can include projectile vomiting and diarrhea, which means that it is often mistaken for a stomach bug. There is almost always a delayed onset of symptoms - often vomiting occurs 2 hours after eating a trigger food, with diarrhea following 5 hours after eating. Some children experience relatively mild symptoms, while others have such severe vomiting and diarrhea that they can become seriously dehydrated and go into shock.

Diagnosing and Treating FPIES

It can be difficult to diagnose FPIES because blood allergy tests only look for IgE-mediated responses. Usually a diagnosis occurs after repeated reactions. Keeping a food journal may be helpful in identifying triggers if you think your child has FPIES.

Treating FPIES varies depending on the child, their triggers and reactions. For infants with FPIES an elemental formula like Neocate is often used. For some children who have fewer triggers treatment is simply to avoid those foods. Introducing new foods slowly – one at a time and for up to three weeks – is extremely important to identify both safe and trigger foods. If your child has an FPIES reaction, it is important that they remain hydrated to avoid going into shock.

Outgrowing FPIES

Many children with FPIES outgrow the disease by age three, but this can vary based on how severe their symptoms are and which foods they react to. According to an article from Kids With Food Allergies, one study showed that 100% of children with FPIES reactions to barley had outgrown and were tolerating barley by age three, while only 40% of those with FPIES to rice, and 60% to dairy tolerated it by the same age.

To determine if your child has outgrown FPIES it is important to work with your doctor and evaluate it on a food-by-food basis. Atopy patch testing can help assess if your child is ready for an oral challenge in your doctor’s office or hospital (do not attempt without a doctor’s supervision!).

We hope this helps shed some light on an often confusing disease. If any of you have children with FPIES and can share your experiences, please leave a comment!

- Sarah

You may have noticed that allergies and asthma often go hand in hand. Roughly, 70% of children with asthma have some type of allergy[1]. So do allergies cause asthma? Or does asthma cause allergies? The answer to both questions is no; one does not cause the other but the two conditions do have a strong connection.

Inflammation & Your Immune System

Allergies and asthma are both inflammatory conditions caused by dysfunction of the immune system. Sometimes they are referred to as “atopic diseases”. The immune system is the body’s defense to foreign invaders, such as bacteria, viruses, pathogens, fungi, etc. When the immune system detects these foreign invaders, it releases cells that seek out and destroy them. Inflammation is one of the first responses of the immune system to infection. Usually, the immune system keeps us healthy; however, a malfunctioning immune system can lead to illness. This is what happens with allergies and asthma.

Asthma vs. Allergies

With allergies, the immune system is hyperactive and produces an unnecessary inflammatory response to a traditionally harmless substance (such as a food protein). Asthma is a chronic lung disease characterized by episodes of inflammation and narrowing of the airway in response to certain "triggers." These triggers vary from patient to patient and may include infectious agents, exercise, stress, pollutants such as cigarette smoke, and common allergens such as cat dander, dust mites, and pollen.

Is there a link?

There are approximately 9 million kids in the US who have asthma[2]. Of this 9 million, about ¾ have asthma that is triggered by allergies. Remember, we talked about different triggers for asthma symptoms (exercise, pollen, allergens, etc.). Patients whose asthma is triggered by allergens are often said to have “allergic asthma”. [3] According to the Asthma and Allergy Foundation of America, allergic asthma is the most common type of asthma, affecting around half of asthma patients.

Does Genetics Play a Role?

Atopy refers to the genetic tendency to develop allergic diseases, such as eczema, allergies and asthma[4]. Someone with “atopy” produces certain antibodies associated with allergic disease. Genetics and environmental factors both contribute to whether a patient does or doesn’t develop atopic diseases. Not all people with atopy (that genetic predisposition) go on to develop allergic diseases because environmental factors play a role too; However, they are significantly more likely to. Likewise, not all people with atopic disease have atopy (but most do).

Genetics obviously plays a big role in the development of allergic diseases. If one parent has an atopic condition, their child has a 1 in 4 chance of having some form of atopic disease (not necessarily the same one as the parent)[5]. If both parents have an atopic condition, the child is more than 50% likely to develop an atopic disease.

Hopefully, this information gives you a better understanding of why asthma and allergies are so often seen together. While neither one causes the other, some people have a genetic predisposition which puts them at a greater risk for developing all forms of allergic disease (such as allergy, eczema and asthma). So if you have one allergic disease, you have a higher risk for developing other types of allergic conditions in comparison to the general population.

Have you found this to be true with your little ones? Be sure to share your experiences with us in the comments!

- Mallory

[1] World Health Organization. Global surveillance, prevention and control of chronic respiratory disease: a comprehensive approach, 2007.
[2] The Nemours Foundation/KidsHealth^®© 1995- 2010. http://kidshealth.org/.
[3] American Academy of Allergy Asthma & Immunology.
[4] Atopic Diseases in Childhood. Gold MS and Kemp AS. MJA 2005; 182 (6):298-304. [5] The National Eczema Association. http://www.nationaleczema.org/.

Parents often ask us if their second child has an increased risk of allergies if their older sibling has them.  So, in today’s post, we’ll discuss the genetics of allergies.

The exact cause of allergies is unknown, but researchers suspect that they are most likely caused by a combination of both genetics and environmental factors.

Genetic Factors:

“Atopy” is a term used to describe the genetic predisposition to develop allergies or allergic diseases.  Allergies and allergic disease may include eczema, asthma, food allergies, etc.  

Studies show that if one parent is “atopic”, at least 30% of their children will have allergies[i]. If both parents are atopic, this value goes up to 50%.  Although a familial history of allergy puts you at an increased risk of developing allergy, you will not necessarily develop the same type of allergy or allergic disease as your family member[ii].  Atopy describes a predisposition for allergic disease in general.  The presentation and type of allergic disease may vary from family member to family member (for example, a parent has an allergy to pet dander and their child has an allergy to milk protein).

Environmental Factors:

Not all individuals with a genetic predisposition for allergies will go on to develop them because the environment plays an important role too.  It is difficult to know how much is determined by genetics and how much is determined by environmental factors because family members are often exposed to the same environmental factors.  Research on identical twins raised in different environments has shown that there is some discrepancy in the development of allergies despite a shared genetic predisposition.  This suggests that although there is a strong genetic component, environmental exposure is quite influential as well[iii].

What can you do?

You cannot modify a genetic predisposition for developing allergies (at least not yet!), you can alter the environmental exposures, which influence the development of allergies.  External environmental factors like smog, car exhaust, pollen, etc are difficult to alter unless you move to a different location. However, it is possible to reduce the indoor environmental  factors in your home. Whether or not this is effective in preventing allergies in those predisposed to them is still unclear but it certainly couldn’t hurt.  There is also a great deal of interest in whether dietary modifications, both for the mother during pregnancy and for the infants during the first year or life, can protect infants predisposed to developing allergic disease.  At this point, there is not enough  evidence to make a strong recommendation on preventive practices. However, research shows that introducing foods (anything other than breast milk or formula) during the first 4 months of life is associated with the development of allergies so refraining from this is one more way you may be able to protect your little one from developing allergies.

-Mallory

 [IMAGE: http://office.microsoft.com/en-us/images/results.aspx?ex=2&qu=dna#ai:MP900321102|mt:0|]