Allergies, Intolerances and Eosinophlic Disorders: What's the difference?
The gastrointestinal tract is uniquely designed to digest a variety of foods that help children grow and thrive. However, sometimes the body reacts negatively to certain foods, leading to discomfort or more serious symptoms.
Food Allergies: IgE vs. Non-IgE Reactions
A true food allergy occurs when the immune system mistakenly identifies a food as harmful and reacts to its proteins (allergens). This immune response can be categorized into two types:
IgE-Mediated Food Allergies
- These involve antibodies called immunoglobulin E (IgE) and typically cause immediate reactions, such as hives, trouble breathing, swelling, or vomiting.
- Severe reactions can lead to anaphylaxis, requiring epinephrine (EpiPen) injection.
- Think of this response like a bee sting allergy—fast and potentially dangerous.
Non-IgE-Mediated Food Allergies
- These cause delayed reactions, such as abdominal pain, diarrhea, or eczema, which can appear hours or even days after eating the food.
- A good comparison is poison ivy, where the immune reaction takes time to develop.
- In some cases, eosinophilic gastrointestinal diseases (EGIDs), such as eosinophilic esophagitis (EoE), occur when white blood cells (eosinophils) build up in the digestive tract after eating certain foods.
- This can lead to chronic inflammation, causing symptoms like trouble swallowing, vomiting, reflux, or poor growth.
The most common food allergens in children (both IgE and non-IgE) include milk, soy, eggs, wheat, peanuts, tree nuts, fish, and shellfish.
Food Intolerances vs. Food Allergies
A food intolerance or sensitivity happens when the body has trouble digesting certain foods, but the immune system is not involved.
- A common example is lactose intolerance, where the digestive system lacks the enzyme lactase, making it difficult to break down milk sugar.
- Food intolerances can cause bloating, gas, diarrhea, or stomach pain, but they do not trigger an allergic immune response.
Diagnosing Food Allergies
Food allergy testing often involves:
- Blood tests (for IgE-mediated allergies).
- Skin prick tests (performed by an allergist).
- Oral food challenges (under medical supervision).
Early food introduction, especially for infants at risk, may help reduce the likelihood of developing allergies. Research, including the landmark Bamba study, suggests that early exposure to peanut-containing foods may lower the risk of peanut allergies in some children.
Treatment & Management
- Dietary modifications: Avoiding trigger foods is the main approach, but overly restrictive diets can affect a child’s nutrition and growth.
- Medications: Some children may benefit from antihistamines, epinephrine (for severe reactions), or other treatments.
- Guidance from specialists: A pediatrician, allergist, or pediatric gastroenterologist can help with diagnosis and personalized management.
Conclusion
Understanding the difference between food allergies and intolerances is crucial for managing symptoms and ensuring a child’s healthy growth. While food allergies involve the immune system and can be severe, food intolerances affect digestion but are not life-threatening. Proper diagnosis and guidance from a healthcare provider can help ensure a safe and balanced diet for children with these conditions.