Distinguish between a food allergy and a food intolerance.

• A. A food allergy involves an immune response, often IgE-mediated; a food intolerance is a non-immune adverse reaction.
• B. A food allergy is always mild; a food intolerance is always life-threatening.
• C. A food allergy is caused by lactose; a food intolerance is caused by peanut proteins.
• D. A food allergy only affects digestion; a food intolerance only affects skin.

Answer: (A)

Food allergies are immune-mediated reactions to a food protein, most often driven by IgE antibodies, which can trigger rapid and potentially life-threatening symptoms such as hives, swelling, throat tightness, or anaphylaxis. Food intolerances, on the other hand, are non-immune adverse reactions, usually caused by enzymatic or metabolic problems (like lactase deficiency), leading to symptoms that are typically digestive (gas, bloating, diarrhea) and not life-threatening. This contrast—immune involvement versus non-immune mechanisms—is what distinguishes the two.

Lactose intolerance is an example of a non-immune issue, while peanut protein is a classic allergen that can provoke a true immune response. Allergic reactions can be severe, whereas intolerances rarely pose that level of risk.