What distinguishes an allergic reaction from a side effect?

An allergic reaction is indeed distinguished from a side effect by being immune-mediated. This means that an allergic reaction involves the immune system's response to a substance, which can lead to symptoms such as hives, swelling, or anaphylaxis. The immune system mistakenly identifies a normally harmless substance as a threat, resulting in a reaction that can vary in severity.

In contrast, side effects are typically pharmacological effects of a drug that are not related to the drug's therapeutic effects. They can arise from the drug’s action but do not involve the immune system. Side effects are generally expected based on the drug’s known effects and can occur with any medication regardless of the patient’s immune response.

While some allergic reactions can be serious, not all side effects are mild, and not all allergic reactions occur after multiple doses. Moreover, allergic reactions are often unpredictable and may vary in occurrence and severity among individuals. This distinction is critical for healthcare professionals to identify and manage patient reactions appropriately. Understanding these differences helps in monitoring patients for adverse effects and providing the necessary interventions.