Food Allergies: Signs, Symptoms, and Management
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Food Allergies: Signs, Symptoms, and Management

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Food Allergies: Signs, Symptoms, and Management

Posted 2 years ago

Brian Stanton

Brian Stanton


SaVanna Shoemaker, MS, RDN, LD

SaVanna Shoemaker, MS, RDN, LD

Expert Approved

If food allergies haven’t yet touched your life, they may soon. About 1 in 10 adults (and 1 in 12 children) have this atypical immune response to cow’s milk, tree nuts, and a handful of other common allergens.[*]

For some people, even trace amounts of an offending food can trigger life-threatening anaphylaxis. These folks must be extremely mindful of what they ingest. 

In this article, you’ll learn the signs of food allergy, the most common food allergens, the process of food allergy testing, and tips for managing food allergies. Let’s get started by laying some groundwork. 

What Is A Food Allergy?

A food allergy is an abnormal immune response to a specific food or group of foods. This immune response is typically mediated by immune molecules called IgE antibodies, but other immune molecules (like mast cells and histamine) also play a role.[*

Food allergies develop similarly to seasonal allergies. The development process, called “sensitization,” involves several steps[*]:

  • Exposure to the allergen (wheat, for instance)
  • The production of IgE antibodies in response to the allergen
  • The attachment of IgE antibodies to mast cells, which in turn release chemicals like histamine that create symptoms each time the allergen is ingested

Food allergies, to be clear, are distinct from food intolerances. Food intolerances aren’t mediated by IgE antibodies but by other factors like low stomach acid, low digestive enzymes, and IgA antibodies.[*] A chronic digestive condition called celiac disease does entail an abnormal immune response to gluten but is classed as an autoimmune condition (not an allergy) as it’s also not driven by IgE.    

Symptoms and Causes of Food Allergies

Unlike seasonal allergies, food allergies are often severe and sometimes life-threatening. The symptoms of a food allergy may present seconds to hours after exposure and may include[*]: 

  • Difficulty breathing 
  • Vomiting, diarrhea, and other GI symptoms 
  • Hives 
  • Low blood pressure 
  • Swelling of the tongue or face

Many of these symptoms are related to anaphylaxis, a dangerous complication of severe food allergy. Occasionally, anaphylactic shock can be fatal. 

Why do some people develop food allergies and others don’t? We don’t know the whole story, but we do know that lifestyle factors matter.

Consider, for instance, that children growing up on farms, children with pets, and children who drink raw milk develop fewer allergies than the general population.[*][*][*] Researchers believe that early exposure to these “friendly” sources of bacteria helps train the immune system to respond to its environment properly.[*

Most Common Food Allergens

A person can become allergic to any food, but the eight foods below are the most common offenders.  

#1: Cow’s milk

Cow’s milk allergy affects 2-3% of babies and toddlers, making it one of the top childhood allergies.[Peanut allergy affects roughly 1-3%% of the population in Westernized countries and persists into adulthood most of the time.[*][*] Researchers are currently trying to desensitize children with peanut allergies by gradually exposing them to these legumes in a controlled setting.[*] ] Fortunately, most children outgrow the condition by adolescence.

#2: Tree nuts

People with a tree nut allergy must avoid almonds, brazil nuts, cashews, macadamia nuts, and other nuts that come from trees. Since tree nut and peanut allergies are responsible for about half of all anaphylaxis-related deaths, clinicians advise patients to carry epinephrine (which can reverse anaphylaxis) in case of accidental ingestion.[*

#3: Peanuts

Peanut allergy affects roughly 1-3%% of the population in Westernized countries, and persists into adulthood most of the time.[*][*] Researchers are currently trying to desensitize children with peanut allergy by gradually exposing them to these legumes in a controlled setting.[*]

#4: Eggs

A person with an egg allergy may be allergic to both egg yolks or (more commonly) egg whites. The treatment? An egg-free diet. 

#5: Wheat

When someone is allergic to wheat, staying safe means avoiding wheat-containing foods. Those with celiac disease must avoid wheat (wheat contains the problematic protein, gluten), but not because wheat will trigger anaphylaxis. 

#6: Soy

Soy allergy sufferers must eschew foods like soy sauce, soy milk, and tofu made from soybeans. Most children with a soy allergy outgrow the condition.[*

#7: Shellfish

Shrimp, lobster, squid, scallops, and other crustaceans and mollusks are off-limits for people with a shellfish allergy. A shellfish-based protein called tropomyosin is the most common offending substance.[*

#8: Fish

About 2% of adults are allergic to fish.[*] Fish allergy symptoms are often confused with the symptoms of consuming contaminated fish. 

Testing for Food Allergies

The first principle of food allergy testing is to listen to your body. Pay attention to how specific foods make you feel, and keep a food journal (or log foods in Carb Manager). and use the ‘notes’ feature to document your findings. 

If you think you have a food allergy, visit a qualified medical professional. This professional may recommend[*]:

  • Skin prick testing to test if traces of the food trigger a skin reaction
  • Blood testing for IgE antibodies
  • Oral food challenges in a medically controlled setting

Once you have a diagnosis, the primary treatment is to avoid the offending food. Sometimes food allergies resolve naturally, so talk to your doctor about how to monitor your situation. 

Tips for Managing Foods Allergies

If you or a loved one has a food allergy, keep your head up. Here are some tips to make living with food allergies safer, easier, and more bearable: 

  • Read labels. Packaged foods often contain milk, wheat, soy, and other common allergens. Read labels carefully, and look for warnings like “processed in a facility that also handles tree nuts.” In many instances, allergens will also be ‘bolded’ on the label.
  • Carry an allergy card. An allergy card makes dining out safer and more accessible for allergy sufferers. Just show it to your server and they’ll know which foods to shield you from. 
  • Use Carb Manager. Filter for top allergens, track macros, and stay safe by designing your diet with the Carb Manager app. Living with food allergies just got easier. 
  • Work with your doctor. Your doctor may recommend carrying epinephrine, taking specific tests, or considering certain medications. Modern medicine is a wonderful thing, so take advantage. 

Food allergies are no fun, but these tips make living with them more tolerable. Once you have a food allergy strategy in place, you can get back to the rest of your life.