Food allergies are on the rise, affecting approximately 1 in 13 American children. For those parents who have experienced food allergies first-hand, it can be overwhelming and scary.
To help us better understand what we need to know about pediatric food allergies, we’ve partnered with world-renowned allergist and immunologist Dr. Sanjeev Jain, founder of Columbia Allergy, an allergy clinic with locations throughout the Pacific Northwest. In this Q&A, Dr. Jain breaks down common food allergies, what parents should look for, and options for treatment.
What are the most common food allergies in children?
There are eight top food allergens that are responsible for a majority of known food allergies. These foods include: peanuts, tree nuts (almonds, walnuts, pecans, cashew, etc.), soy, milk, egg, shellfish (lobster, crab, shrimp, etc.), fish (cod, bass, flounder, etc.), and wheat. Recently sesame seed has been added to the list of top allergens.
It is important to recognize that children can develop allergy to any food. We often also see allergies to fruits such as strawberry, banana, tomato, or avocado, vegetables such as carrot or green beans, and spices such as cinnamon. Many processed foods contain nuts, dairy, soy, or are made in facilities that also process these materials. Even a small amount of cross-contamination by these allergens can lead to a life threatening reaction if someone has a severe, or anaphylactic, allergy to these foods.
At what age do food allergies usually appear?
Food allergies in children typically appear within the first 24 months of life. Peak prevalence is within the 1st year of life and decreases, but still occurs, throughout the rest of childhood.
An allergic reaction to food can only occur on a subsequent exposure, and not at the time of an initial exposure. As children are exposed to highly allergenic foods for the second time or later, you may see an allergic reaction occur.
Often, children get exposed to staple foods such as dairy, egg, wheat, soy, and peanuts without parents even recognizing when the first exposure happened. While most individuals develop food allergies during childhood, new-onset allergy can develop at any age. New research shows that early introduction of highly allergenic foods around six months of age can reduce the risk of developing allergies to those foods later.
What is the difference between a food allergy, an intolerance, and a sensitivity?
A food allergy is an allergic response in which the immune system is activated to respond to the food protein that is seen as a threat. This type of reaction is IgE mediated, so it can be tested for using skin prick testing or IgE lab testing. When the immune system gets involved, you can have localized gastrointestinal symptoms as well as systemic symptoms that affect other body systems such as your lungs, cardiovascular system, and skin. The symptoms may not be directly related to the amount of food a person is exposed to. Exposure to even a microscopic amount could potentially lead to a life-threatening reaction in persons with severe food allergies. Symptoms of an allergic reaction to food can include hives, wheezing, coughing, dizziness, a drop in blood pressure, abdominal pain, vomiting, and swelling of the face, throat, or skin.
A food intolerance refers to difficulty digesting or metabolizing a component of food. Food intolerances are more common than food allergies. They are typically caused by a missing enzyme or ability to break down a specific component of a food. For example, persons with lactose intolerance are found to be missing the lactase enzyme needed to break down the lactose found in dairy products. Food intolerances will generally not cause systemic symptoms, and will only cause gastrointestinal upset. The severity of symptoms is typically related to the amount of the food ingested. For example, a person with lactose intolerance would develop more significant symptoms when eating a whole bowl of ice cream versus eating just a scoop of ice cream. Food intolerance symptoms typically include gas, bloating, abdominal pain, and diarrhea.
Food sensitivities are not as well-defined as food intolerances and food allergies. The term food sensitivity is typically used to refer to symptoms that may develop after eating that are not explained by a food allergy or a known food intolerance. This term has become more popular as companies such as Everlywell test for this type of food reaction by analyzing IgG markers, another type of immune mediator released by the immune system. Symptoms typically related to this category include more vague symptoms like bloating, stomach pain, diarrhea, headaches, and joint pain. There is limited scientific evidence related to this category at this time. Many individuals have sensitivities such as gluten sensitivity, but only a fraction of them have a well recognized medical condition such as celiac disease.
Do food allergies ever go away on their own?
Some food allergies are life-long, while others can be outgrown during childhood as the immune system continues to develop and change. It is less likely for adults to outgrow an allergy.
While the mechanism of immune tolerance has been studied extensively by scientists, it is difficult to predict who will naturally outgrow their food allergies. Typically, individuals with a history of milder reactions and low specific IgE levels are more likely to outgrow their allergies. As patients are outgrowing their allergies we often see a reduction in IgE markers for that specific food indicating the immune system has reduced amount of the key mediator to fight off the protein in the food. Food allergy symptoms can also resolve while still having IgE markers for the food, so this is not a hard rule.
If a child has a moderate-severe food allergy, it is best to test for resolution of the allergy by completing a food challenge in an allergist’s office. Regardless of the severity, tolerance to foods can be induced by oral or sublingual immunotherapy.
What should a parent be on the lookout for with food allergies?
As mentioned above, symptoms of a food allergy can include hives, wheezing, coughing, dizziness, a drop in blood pressure, abdominal pain, vomiting, and swelling of the face, throat, or skin. Food allergies will typically occur within the first year of life and will occur when a person is introduced to the food for a subsequent time. Symptoms can occur immediately or be delayed by several hours, so it’s best to monitor children when you begin to introduce new foods into their diet.
Kids are more likely to develop a food allergy if they or someone in their immediate family have other atopic conditions such as allergic rhinitis (hayfever), eczema, asthma, or if a parent or sibling also has a food allergy. While the top eight allergens are the most common foods that cause allergic reactions, other foods have the potential to do so as well.
If you suspect your child has food allergy we recommend scheduling a consultation with an allergist so the child can undergo food testing. After test results are obtained, the allergist can help to create a safe food introduction plan, and manage food allergies safely. Some allergists are also able to induce tolerance to the food allergen through the process of desensitization.
Columbia Allergy has clinics throughout the Portland metro area. For more information on allergy testing and treatment, make an appointment at your nearest Columbia Allergy location.
The information provided on this website does not substitute professional medical advice. Content contained in on this website is for general information purposes only. Always seek the advice of a physician or other qualified health care provider with any questions you may have regarding your own medical condition or treatment.