Food Allergy. The underlying cause of food allergies is still not well understood. Food allergies occur because the body interprets a food as being dangerous, and tries to defend itself by activating the immune response with antibodies called Immunoglubin E (IgE). These antibodies cause cells to release chemicals, causing an allergic reaction. Signs of IgE mediated food allergy usually occur immediately after ingestion and include hives, redness of the skin, vomiting and anaphylaxis . Unlike with food intolerances, it is important to carry epinephrine and create an anaphylaxis treatment plan.
Other health issues that are IgE mediated include:
- Anaphylaxis — life-threatening reaction
- Food dependent exercise induced anaphylaxis (FDEIA)
- Oral Allergy Syndrome (OAS) – pollen associated food allergy syndrome, often due to a cross-reactivity between plant proteins from pollen and fruits or vegetables
Food Intolerance. In contrast, food intolerances are a result of the inability to break down food and may cause symptoms such as headaches, digestive symptoms and itching. Some food intolerances are due to deficiencies in enzymes, or sensitivities to food additives or naturally occurring chemicals in foods. Individuals can eat small amounts of the food without causing life threatening problems.
Some example of food intolerances are:
- Lactose Intolerance – inability to digest lactose enzyme
- Irritable Bowel Syndrome – pain in large intestine causing cramps, diarrhea or constipation, bloating and gas
- Sensitivity to chemicals, such as naturally occurring sulfites found in wine, canned or preserved foods which may cause swelling, itching and digestive problems
Other Conditions. Some people have adverse reactions to food unrelated to IgE, making it difficult to diagnose. Some examples of this include:
- Eosinophilic Esophagitis (EoE) – inflammation in the esophagus, caused by a variety of factors
- Food Protein Induced Enterocolitis Syndrome (FPIES) – a rare and potentially severe reaction to food proteins that causes delayed vomiting and diarrhea
- Food Protein-Induced Allergic Proctocolitis (FPIAP) – infants with blood in the stool
- Celiac Disease – a genetically predisposed condition in which ingestion of gluten leads to damage in the small intestine
- Eczema – causes itchy and rough skin due to a variety of factors
Please schedule an appointment with our board certified allergists to help you diagnose and rule out whether you have a food allergy.