Jyoti Kinghorn 
Food allergy is an adverse immune reaction the body has to certain foods. When someone has a food allergy, their body’s immune system regards specific proteins present in certain foods as harmful pathogens. The resulting immune response can range from bothersome to life-threatening.
Symptoms include hives, abdominal pain, vomiting, diarrhea, itching in the mouth, cough, shortness of breath, a hoarse or tight throat, and trouble swallowing. The most serious symptom is anaphylaxis in which the immune system reacts so strongly to a food protein that the whole body goes into shock. There is a sudden drop in blood pressure and narrowing of airways which makes breathing difficult. Upon anaphylaxis, a person needs an immediate injection of epinephrine (adrenaline). Without it, anaphylaxis can be deadly in just 30 minutes.
About 90% of all food allergies are from one of nine foods- eggs, milk/dairy, peanuts, tree nuts, fish, shellfish, wheat, soy, and sesame. The foods that cause the most food allergies are eggs, milk, and peanuts whereas the most severe allergic reactions occur in response to peanuts, tree nuts, fish, and shellfish.
The incidences of food allergies in children are increasing. Now, about 1 in 13 children has a food allergy. As children grow, allergies to milk, eggs, wheat, and soy may go away, though allergies to peanuts, tree nuts, fish, and shellfish often persist.
Food allergies can have a negative impact on a person’s quality of life. Because of the ubiquitous nature of many of the allergens such as eggs and dairy, individuals with food allergies and parents of children with food allergies have to exercise caution and read the ingredients before purchasing anything to eat. This can make it hard to eat out at parties, eat when traveling, or enjoy street food, which can be an isolating experience. The fear of accidentally ingesting an allergic food can have an impact on a person’s social life and what activities they may be able to take part in.
As of now, food allergies cannot be cured, though they can be managed by diet restriction and medication.
Managing food allergies
Guidelines to manage food allergies have been changing. Traditionally, the approach towards food allergies was one of avoidance- parents who had a certain food allergy or whose older kids had a certain food allergy were recommended to avoid giving that food to their infants when they first started eating. That guideline has changed in recent years. It is now recommended that parents should introduce possibly allergic foods to their infants between 4-6 months of age to desensitize them to the allergen(s). The specific age for introducing specific foods to a baby differs from country to country.
Emerging treatments for food allergies
With upcoming treatments and a better understanding of what causes food allergies, there is much hope for people with food allergies.
Prebiotics and probiotics
It is being increasingly understood that the gut microbiome (all microorganisms that live inside our gut) has a connection with many different aspects of our body functions, including immunity. Gut bacteria thrive on fiber, so eating high-fiber foods such as whole grains and cabbages is optimal for maintaining healthy levels of gut microbiome. However, people’s diets have been steadily incorporating more processed food with lesser natural fiber, making conditions less optimal for a healthy gut microbiome.
An additional emphasis on sanitization and cleanliness has led to a much lower introduction of microorganisms to children through diet and play. While this has had a positive impact in reducing childhood infections, it has also affected children’s immunity negatively and may have reduced the diversity of gut microbiome.
Aberrant immunity reactions such as eczema and food allergies may be caused by poor microbial diversity or wrong proportions of bacteria in the gut, as well as the metabolic activity of these bacteria.
Therefore, eating prebiotic foods (e.g. bananas, whole grain bread or pasta, cabbage, eggplant, artichoke, etc.) and probiotic foods (e.g. yogurt, kefir, kombucha, sauerkraut, sour cream, aged cheese, etc.) can improve the health and diversity of the gut microflora which may also reduce allergies.
Oral immunotherapy (OIT)
In oral immunotherapy (OIT), a small amount of a food allergen is given daily for a year to build up tolerance for the food. It has led to success in preschool children to the point where they can free-eat the allergic food after OIT. Children can receive OIT for multiple foods at once. But it has to be done in closely monitored conditions under a physician’s care. While OIT is successful 80% of the time, about 14% of recipients can have anaphylaxis so having epinephrine injections close by is critical.
Epicutaneous immunotherapy (EPIT)
Epicutaneous immunotherapy (EPIT) utilizes a similar principle as OIT of introducing the allergen in small doses. In EPIT, patients wear a small adhesive patch that delivers a minute amount of the allergen into the skin. The dose is gradually increased with the end goal of training the person’s immune system to tolerate the food allergen. EPIT can induce desensitization to allergens in half the children under therapy with 4%a risk of anaphylaxis.
Biologic medications targeting immune responses
Biologics are considered the most exciting and game-changing advance in the field of food allergies. Biologics are medications that target the underlying immune mechanisms that cause food allergies.
In February of 2024, the FDA approved the first biologics medication Xolair (omalizumab) to “help reduce allergic reactions to multiple foods after accidental exposure”.
A lot of food allergies are triggered by immunoglobulin E (IgE) antibodies made by the immune system. The drug Xolair binds to IgE and blocks it from binding its receptor, thereby neutralizing its activity.
The drug is given solely to prevent serious adverse effects due to accidental exposure. The foods that cause allergies must still be avoided when taking Xolair.
Other biologics drugs such as dupilumab, antialarmins are also being studied as therapies to counter food allergies. Dupilumab targets molecules released by the immune cells that cause inflammation. Antialarmins have been used so far to treat asthma. Researchers are also testing the use of abrocitinib, an eczema medication to treat food allergies.
The information provided in our blog posts is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this blog.
