You’ve probably experienced it before—you eat something and shortly after feel unwell. Maybe your stomach feels bloated, you feel nauseated, or you notice itching or discomfort. It’s natural to wonder whether you’ve developed a food allergy or if you’re experiencing a food intolerance or sensitivity.
Although food allergies and food intolerances are often confused—and may share some overlapping symptoms—the differences between them are very important. Food intolerances can cause uncomfortable digestive symptoms, while true food allergies involve the immune system and can be serious or even life-threatening. Understanding the distinction can help you know when testing, treatment, or emergency care is needed.
If you think you can “sometimes” eat a food you react to, it’s important not to guess. Proper evaluation and diagnosis by a board-certified allergist can help you avoid unnecessary risks.
What Is Food Intolerance or Food Sensitivity?
Food intolerance (also called food sensitivity) occurs when your digestive system has difficulty breaking down or processing certain foods. Unlike food allergies, food intolerances do not involve the immune system and typically affect only the digestive tract. As a result, symptoms are usually milder and not life-threatening.
Food intolerances may occur for several reasons, including:
Enzyme deficiencies: Digestive enzymes help break food down so nutrients can be absorbed. When these enzymes are lacking, digestion is incomplete. A common example is lactose intolerance, caused by insufficient lactase enzyme.
Sensitivity to food additives: Some people react to preservatives, dyes, or flavor enhancers such as sulfites, MSG, or artificial colors.
Irritable Bowel Syndrome (IBS): IBS is a chronic condition affecting the large intestine. Certain foods and beverages—such as dairy, wheat, citrus fruits, cabbage, or carbonated drinks—may trigger symptoms like cramping, bloating, diarrhea, or constipation.
Celiac disease: Celiac disease is an autoimmune disorder triggered by gluten. While it is not a food allergy or intolerance, consuming gluten causes immune-mediated damage to the small intestine.
Inflammatory Bowel Disease (IBD): Conditions such as Crohn’s disease can cause severe digestive symptoms and increased sensitivity to certain foods.
Symptoms of Food Intolerance
Food intolerance symptoms are usually digestive in nature and may occur within a few hours after eating as food moves through the digestive system. Common symptoms include:
Upset stomach
Abdominal pain or cramping
Gas and bloating
Diarrhea
Nausea
Heartburn
Headaches
Many people with food intolerances can tolerate small amounts of the food without severe symptoms.
What Are Food Allergies?
Food allergies are very different from food intolerances. A true food allergy involves the immune system, specifically an antibody called Immunoglobulin E (IgE). In individuals with food allergies, the immune system mistakenly identifies a harmless food as a threat and launches an attack.
Once IgE antibodies are produced, they bind to mast cells. When even a tiny amount of the offending food is consumed, these cells release chemicals such as histamine, causing an allergic reaction. In some cases, amounts as small as 1/250th of a peanut can trigger symptoms, which is why “just a taste” is never safe for someone with a food allergy.
The most common food allergens—responsible for the majority of reactions—include cow’s milk, eggs, soy, wheat, fish, shellfish, peanuts, and tree nuts.
Symptoms of Food Allergies
Food allergy reactions typically occur quickly—within minutes to an hour after exposure—and can range from mild to life-threatening. Symptoms may include:
Itching or tingling in the mouth
Swelling of the lips, tongue, face, throat, or mouth
Hives or itchy skin
Abdominal pain
Nausea, vomiting, or diarrhea
Wheezing or difficulty breathing
Dizziness, lightheadedness, or fainting
Anaphylaxis
Anaphylaxis is the most severe form of food allergy reaction and is a medical emergency. Symptoms may include:
Tightening or constriction of the airways
Severe difficulty breathing
Sudden drop in blood pressure (anaphylactic shock)
Rapid pulse
Loss of consciousness
Without immediate treatment—most importantly an injection of epinephrine—anaphylaxis can be fatal. Anyone experiencing these symptoms should seek emergency medical care immediately.
Pollen-Food Allergy Syndrome (Oral Allergy Syndrome)
Pollen-food allergy syndrome, also known as oral allergy syndrome, is a milder form of food allergy seen in many patients with seasonal allergies. It commonly causes itching or tingling of the mouth or throat after eating certain raw fruits or vegetables. While symptoms are usually mild, they can occasionally be more serious, making it important to distinguish this condition from more severe food allergies.
Diagnosis and Testing
Testing for food allergies should always be performed and interpreted by a board-certified food allergist. At ENT & Allergy Associates, allergists evaluate test results alongside your medical history and symptoms.
Skin prick testing is one of the most common diagnostic tools. A small amount of allergen is placed on the skin and lightly pricked. After about 15 minutes, the area is evaluated for a reaction. This test is fast, effective, and allows multiple allergens to be tested at once. Skin testing does not diagnose food intolerances or sensitivities.
Treatment for Food Allergies
Once diagnosed, strict avoidance of the allergen is essential. Even if previous reactions were mild, future reactions can be more severe.
Treatment may include:
Epinephrine auto-injectors (EpiPen, Auvi-Q): Life-saving emergency medication used to reverse anaphylaxis
Antihistamines: Used for mild symptoms such as itching or hives
Corticosteroids: May be used to reduce inflammation during severe reactions
Anyone who uses epinephrine should seek emergency medical care immediately, as symptoms may return after the medication wears off.
Managing Food Intolerance
Food intolerances do not require emergency treatment. Management typically involves reducing or avoiding trigger foods. An elimination diet—temporarily removing suspected foods and then reintroducing them one at a time—can help identify problem foods. Keeping a food diary may also be helpful.
If an underlying condition such as IBS, celiac disease, or Crohn’s disease is present, treating that condition may improve food-related symptoms.
See an Allergist at ENT & Allergy Associates
If you believe you or your child may have a food allergy, professional evaluation is essential. The food allergy specialists at ENT & Allergy Associates provide comprehensive allergy testing, diagnosis, and personalized treatment plans to help you manage symptoms safely and confidently.
Contact ENT & Allergy Associates today to schedule an appointment at one of our convenient locations in New York, New Jersey, Pennsylvania, and Texas and learn more about food allergy testing and care.
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