**Immediate IgE Food Allergy**, as the name suggests, occurs when the body has an allergic reaction immediately or within 30 minutes to two hours after exposure to a food allergen (triggered by Immunoglobulin E (IgE) antibodies). Consequently, it is immediately apparent what caused the allergy. Common allergens such as dust mites, animal dander, pollen, mold, and seafood are among those that can be detected through IgE testing.
In contrast, **delayed IgG Food Hypersensitivity (chronic allergy)** refers to allergic symptoms that appear much later, typically several hours or even days after consuming the triggering food. This makes it very difficult to pinpoint the specific food responsible for the reaction without testing. By undergoing a blood test for chronic food allergen IgG, the triggers can be clearly identified. These allergens are often foods we consume regularly, such as eggs, milk, wheat, soy, nuts, etc.