What is a medication allergy?

A medication allergy refers to an adverse reaction that occurs when the immune system mistakenly identifies a medication as a harmful substance. This immune response can trigger various symptoms, ranging from mild to severe, including hives, swelling, difficulty breathing, and anaphylaxis. Understanding that a medication allergy is about the body’s immune reaction is crucial; it is not simply a heightened sensitivity or an issue of tolerance but rather a specific response that involves the immune system.

In contrast, increased sensitivity to a medication describes a situation where a person experiences amplified effects of a drug, but this is not necessarily an allergic response and does not involve the immune system. Additionally, a preferred type of medication refers to choices made based on therapeutic advantages or efficacy, rather than any adverse reactions. Similarly, tolerance indicates that a person needs a higher dose over time to achieve the same effect, which is a different pharmacological phenomenon and does not directly relate to allergies.