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Written by: Darius Bolton Mar 05, 2024

Food Allergies vs Food Intolerance: What Does My Child Have?

Food allergies or food intolerance. What does your child have? Introducing young children to new foods can be a fun and exciting time for parents. But that excitement can quickly turn to worry or stress if a child has a negative reaction to a food, starts having digestive symptoms, or isn’t developing in a healthy way. Depending on the symptoms your child is exhibiting, various tests and concepts like food allergies and food intolerance may be discussed.

For a parent new to the world of adverse food responses, it can be difficult to navigate medical terminology and the different types of reactions that can occur. Some common questions parents may have include: What exactly is the difference between a food intolerance and a food allergy? Does my child need an EpiPen? Will they outgrow this? Which foods need extra attention concerning allergies? How do we test for food allergies? How do I find the best pediatric allergist near me? Can we manage pediatric food allergy with a telehealth or telemedicine pediatric allergist near me? What are the symptoms of pediatric food allergy? What are the most common food allergies? What causes food allergies? What helps food allergy? Can we treat food allergies? There are so many other questions, and this can be overwhelming.

Understanding current information around food reactions is an important part of managing food sensitivity or food allergy in your child and promoting the best possible outcomes. Knowing the different types of food reactions, their symptoms, and how to manage them makes food allergies and food intolerances in children easier to navigate. Knowing where to find the best pediatric allergist for your family can make things a lot simpler.

  • What is a Food Allergy?

A food allergy is a reproducible adverse effect that is a result of an immune response from exposure to a specific food. In the medical world, adverse food reactions are categorized by whether or not they involve the immune system. The immune system controls how the body defends itself. Since there are different types of immune cells, the symptoms of food allergy depend on which parts of the immune system are at work.

One major component of the immune system is known as immunoglobulins, or antibodies. These are different types of proteins designed to attack and neutralize anything they consider foreign such as viruses, bacteria, venom, parasites, and allergens. Immunoglobulin E (IgE) is the antibody responsible for allergic reactions and it plays a large role in diseases or symptoms like asthma, seasonal allergies, food allergies, and hives.

On a basic level, food allergies are immune-mediated, and intolerances or sensitivities are non-immune-mediated. Some food allergies involve a combination of IgE and other parts of the immune system. The three major types of immune reactions in food allergy include: 

  • IgE-mediated – immune response is caused by Immunoglobulin E (IgE) antibodies responding to allergens.
  • Non-IgE-mediated – immune response is caused mainly by other cell-mediated mechanisms.
  • Mixed IgE-and non-IgE-mediated – reaction to the food is caused by both IgE-mediated and non-IgE-mediated (cell-mediated) immunological mechanisms.

  • Food Allergies: Immune-Mediated Response

IgE-mediated food allergy:

An IgE-mediated food allergy looks like what most people probably picture when someone says they are “allergic” to a food, like peanuts. A rapid onset of fairly obvious symptoms, like a swollen face, swollen lips, swollen throat, tingling in the mouth, itchy rash, runny nose, watery eyes, vomiting, nausea, diarrhea, difficulty breathing, increased heart rate, dizziness, and confusion. A severe IgE response can result in anaphylaxis, which is a whole-body reaction where symptoms progress so quickly and severely that they result in unconsciousness and possibly death if not treated quickly. Some symptoms of anaphylaxis from a food allergy include impaired breathing and rapid drop in blood pressure. A milder IgE response might have milder symptoms including an itchy, tingly sensation of the tongue or mouth, or a mild redness and itching where the offending food touched the skin.

Non-IgE-mediated food allergy:

In non-immunoglobulin E-mediated (non-IgE-mediated) response, other immune system components are entirely responsible for symptoms. Non-IgE-mediated food responses are often characterized by gastrointestinal symptoms, respiratory reactions, and skin disorders. These responses usually involve the immune system attacking the lining of the gastrointestinal tract whenever proteins of the allergic food are detected in the body. Symptoms can include vomiting, abdominal pain, diarrhea, poor nutrient absorption, fatty stools, poor growth, and failure to thrive. Depending on the location of the attack and where subsequent inflammation occurs, other serious disorders may arise. A non-IgE-mediated response to the skin can also occur. This often results in contact dermatitis, localized redness, swelling, and itching where an allergen has touched the skin. Unlike IgE-mediated reactions which often have an immediate-onset within two hours of food ingestion, non-IgE-mediated reactions are delayed in onset and can occur up to 28 hours after ingestion of the allergen.

Celiac Disease is an example of a non-IgE-mediated food allergy. In celiac disease, consumption of gluten triggers an immune response in the small intestine. Over time, the lining of the small intestine is damaged, causing an inability to absorb necessary nutrients from foods and increasing the risk for serious heart problems.

Mixed IgE- and non-IgE-mediated food allergy:

A mixed food allergy is a food allergy response that involves both IgE- and non-IgE-mediated mechanisms. An example of a mixed immune-mediated allergy response is atopic dermatitis, or eczema. Repeated exposure to a food allergen causes a chronic release of immune components to the skin, disrupting the skin’s natural barrier and causing inflamed, itchy, dry, and cracked skin to become more susceptible to bacterial infections. Eczema can affect any part of the body but is most prominent in the hands, face, inner elbows, and knees. 

Another type of mixed IgE- and non-IgE-mediated response to food is eosinophilic gastrointestinal disorders (EGID). In EGID, an ingestion of the offending food causes an abnormal accumulation of eosinophils (a type of white blood cell) in the gastrointestinal tract. Eosinophils are part of the body’s normal immune response and are responsible for protecting the body from allergens, foreign bacteria, and dangerous pathogens. Although eosinophils fight diseases, they are also linked to allergic-type reactions. In excessive amounts, they cause inflammation and can release toxins that cause symptoms such as abdominal pain, nausea, vomiting, and diarrhea. Repeated exposure to the offending food causes chronic inflammation of the esophagus, stomach, or intestines. While these symptoms are not immediately life threatening, they can cause malnourishment leading to poor growth and development over time. Extreme inflammation in the throat can lead to more serious health concerns such as increased risk of choking.

  • Food Intolerance or Sensitivity: Non-Immune-Mediated Response

Non-immune-mediated food intolerances or sensitivities are types of food reactions that do not involve the immune system, immunoglobulins, or white blood cells. Food intolerance and food sensitivity are used interchangeably. The actual prevalence of food intolerance is unknown due to the lack of standardized diagnostic tests for most food intolerances and because of discrepancies between perceived and actual food intolerances. However, an estimated 20% of the population suffer from at least some form of food intolerance or sensitivity. A good pediatric food allergist can help you determine if your child has a true food intolerance or sensitivity. 

Food intolerances differ from allergies because they often depend on how much of an offending food is eaten. Larger servings or repeated exposure to a food may be needed before symptoms develop, and even with that, it can still take up to several days for symptoms to appear. On the other hand, allergies are triggered quickly and even a very small amount of the food can cause a serious life-threatening reaction.

Generally, food intolerance in children occurs when their bodies cannot easily break down a particular food or an ingredient in a food. In food intolerance, the body generally has difficulty digesting or metabolizing a certain food or preservative. 

Food intolerances can be host-independent and host-dependent. Host-independent intolerances are reactions that can occur in just about anyone due to a component or chemical in a food. For instance, a migraine from artificial sweeteners can happen to anyone. Host-dependent food intolerances, however, are related to differences in enzymes in people or how their body metabolizes foods. It is dependent on how the host is made up rather than the food alone. Some host-dependent food intolerances include irritable bowel syndrome (IBS) and lactose intolerance which can be hereditary.

A broad range of gastrointestinal symptoms can occur with food intolerances including gas, bloating, nausea, diarrhea, and abdominal pain. Broader symptoms of food sensitivities include headaches or migraines, fatigue, confusion, flushed skin, congested nose, joint pain, and muscle pain.

  • Most Common Culprits

As a concerned parent or caregiver, you may be wondering if your child will someday outgrow their food allergy. If your family has a history of food allergies but your child does not, you also may be wondering if your child will develop food allergies in the future. 

While allergies most commonly develop during childhood, they can occur at any age. For children with food allergies, whether they outgrow the allergy depends largely on which food triggers the response. Almost 80% of children with egg, milk, and wheat allergies will outgrow them by adolescence, but only around 20% of children with nut and seafood allergies ever outgrow their allergies.

The eight most common food allergens for immune-mediated food response or allergies include milk, wheat, eggs, tree nuts, peanuts, fish, shellfish, and soy. Sesame was recently officially recognized by the U.S. Food and Drug Administration (FDA) as the 9th major food allergen. Although a person can develop allergies to any food, these nine foods account for about 90% of all food allergies.

For infants, cow’s milk protein is very often the culprit in allergies since it is the main ingredient in infant formula. Unfortunately, cow’s milk is often poorly tolerated by the immature digestive tract and immune system of an infant. Fortunately though, up to 50% of infants can tolerate cow’s milk by the first year of age and 90% can tolerate it by three years old. The protein present in cow milk is one of the few proteins that can cross into the breast milk so breast-fed infants can experience similar reactions as babies fed with milk-based infant formula.

For non-immune-mediated responses or intolerances, the culprit could be anything. However, food intolerances are commonly caused by foods containing preservatives or dairy. Lactose intolerance is a host-dependent intolerance where individuals lack enzymes needed to properly break down dairy products like milk, cheese, butter, or ice cream. Incidentally, nearly all infants are born with higher levels of lactase (milk-digesting enzyme) because of the biological expectation that they will drink human milk in infancy. However, this enzyme decreases as children enter toddlerhood and wean off breastmilk; thus, lactose intolerance sometimes shows up when children are a few years of age or older.

Gluten is also a common culprit for food reaction, though unlike people with Celiac disease, people with gluten intolerance experience less severe symptoms and can usually tolerate gluten in small quantities. If gluten seems to be linked to uncomfortable symptoms but testing reveals a lack of immune system involvement, then gluten intolerance is the probable cause.

Amines (such as dietary histamine, tyramine, and phenylethylamine) are found in many aged or preservative-containing foods and are poorly tolerated by many people. Common foods containing amines include cured meats, dried fruits, citrus, avocados, aged cheese, smoked meats, soured food like buttermilk, and alcoholic beverages like beer and wine. People who are intolerant to amines have an impaired ability to metabolize ingested amines.

Sulfites are a common preservative and antioxidant additive widely used in foods and pharmaceuticals. Unfortunately, it is often poorly tolerated. They can be found in dried fruits, wine, canned vegetables, pickled foods, condiments, potato chips, beer, and tea. Exposure to sulfites can cause a wide range of unpleasant effects including abdominal pain, diarrhea, flushing, dermatitis, itching, and other serious side effects.

Fructose, aspartame (an artificial sweetener), food dyes, Monosodium Glutamate (MSG), and eggs are other common foods and food additives that people can be sensitive to. Intolerance to some of these foods can cause abdominal issues like nausea, vomiting, and diarrhea.

  • How are Food Reactions Diagnosed?

The method of diagnosing your child’s food allergy depends on the type of medical professional your child is seeing and the symptoms they are having. Whether you are seeing a pediatric allergist, a virtual-first allergist, a telehealth allergist, or a telemedicine allergist, the process of diagnosing and managing your food allergy should be similar if you are working with the best food allergist for your child’s allergy needs. 

For many allergies, the details of your child’s health (including growth), their reaction after eating a certain food, and a physical exam are a large part of the diagnostic process. For IgE-mediated responses, the gold standard is an oral food challenge (OFC). An oral food challenge is where a controlled dose of the suspected allergen is fed to the child and they are observed for a reaction. This is typically only done by a specialist in a setting prepared to intervene should any severe reaction like anaphylaxis occur.

Skin prick tests can also be used at an allergist’s office by injecting a small amount of allergen just beneath the skin and watching for a reaction.

Blood tests can measure general IgE levels. A radioallergosorbent test (RAST allergy test) measures the level of allergen-specific IgE antibodies in the blood and provides more specific information about individual foods. A RAST test can sometimes produce a false positive result; however, it comes in handy for monitoring IgE levels in children who already have a food allergy diagnosis.

Elimination diets are also useful for pinpointing specific allergens. It involves removing a specific food from a child’s diet completely for a period to see if symptoms resolve and then reintroducing that same food to see if symptoms return. An elimination diet is not advisable in situations where a child has had severe allergic reaction like anaphylaxis in the past, or has a serious food allergy.

Elimination diets are useful in mixed immune-mediated allergies and may also include intermittent endoscopy to assess the levels of inflammation over time.

In special situations like celiac disease, blood tests for certain antibodies are helpful as well as elimination diets. Often, the history of symptoms, poor growth, and even sending a soiled diaper to the lab to be tested for microscopic blood can help in the diagnosing process.

Unlike food allergies, food intolerances are more difficult to pin down as there are no current reliable diagnostic tests available to check for sensitivities. Parents may be asked to keep a food diary of everything their child eats for a period and elimination diets might help to single out a particular trigger. Some supporting tests can be done to check for lactose intolerance, including genetic testing, an enzyme breath test, or even a small intestine biopsy. These test results would then need to correlate with symptoms for a definite diagnosis of lactose intolerance to be made.

  • How to Manage Food Reactions

For allergies, avoidance of the offending food and being readily prepared for accidental exposure and subsequent reaction is the gold standard for managing food allergies. For children with symptoms involving difficulty breathing or excessive swelling, particularly of the face or mouth, access to epinephrine (EpiPen) is critical, and parents (and older children) should be taught how to inject it. EpiPens should be kept at home, and a parent or the child should carry one with them whenever they are at school or out of the house. Children should be taught at a young age to ask questions about food they are given outside of the home and learn which foods they need to avoid.

For mixed immune reactions, using a steroid inhaler (like those used for asthma) and swallowing the medication instead of breathing it in can help with inflammation in the digestive tract. Using antacid medications called proton-pump inhibitors (like Prilosec) can be useful in reducing symptoms caused by irritation of the digestive tract.

For symptoms affecting the skin, your child’s allergist will likely recommend a careful regimen of unscented soaps and skin-barrier-protecting moisturizers, as well as steroid creams for flare ups. 

For infants, substituting milk-based formula with an amino-acid formula (or other non-cow’s milk protein formulas) can help with milk-related allergy symptoms. And breastfeeding mothers may need to eliminate cow’s milk products from their diets for the duration of the child’s first year of life while actively breastfeeding.

Any time an elimination diet is needed, especially if multiple foods are restricted, a child’s growth and development should be followed closely so that nutritional deficits do not develop.

For general food intolerances, elimination diets are typically the only truly beneficial option. If the food component a child is avoiding is found in many foods, or spans an entire food group like dairy, it is important to make sure the rest of the child’s diet is balanced. If not, consider supplementing vitamins and minerals they may be missing. An example of this would be providing a calcium supplement to a child avoiding dairy. It can often be helpful to work with a team consisting of a pediatric allergist, a dietitian, and other healthcare providers to thoroughly evaluate your child’s diet to avoid malnourishment, especially at the stage where they are still growing and developing.

Synthetic lactase enzymes, taken in the form of tablets and before eating a food that could potentially be a trigger for food reactions, has been shown to effectively minimize symptoms in children with lactose intolerance. The lactase drops can be added to the food and drink to break down the natural lactose to a form that is more easily digestible.

Restricting certain foods or even frequent digestive tract symptoms can also cause imbalances in the gut microbiome which further contributes to gastrointestinal symptoms. It is important to discuss the option of adding a daily probiotic to your child’s diet with your pediatric allergist.

Whether you are dealing with food intolerance or food allergy, witnessing negative symptoms when your child eats certain foods can be distressing. Receiving a diagnosis can sometimes be a long and stressful process. There may not be a definitive test that can tell healthcare professionals exactly which food is causing your child’s symptoms. Trial and error, symptom tracking, and elimination diets may be your best options, but this lack of precision can sometimes be frustrating. Having a better understanding of how the body is affected by certain foods and whether the immune system is involved in food allergies can help you throughout the experience and empower you to be a part of your child’s diagnosis and treatment. Partnering with a pediatric allergist near you who is accessible to you at times, such as a telehealth allergist or telemedicine allergist, can help make the process easier and smoother. Managing your child’s food allergies and food intolerances can be daunting, but with the right allergist and allergy care team, you will be better prepared and more informed to handle food reaction emergencies should they ever arise.