Food and Drug Allergic Reactions
Allergies and adverse reactions to food and medications are common, and people can have a wide variety of allergic symptoms.
These reactions occur when your immune system overreacts to a food or a substance in a food or drug, identifying it as a danger and triggering a protective response.
Symptoms can range from mild to severe. Just because an initial reaction causes few problems doesn’t mean that all reactions will be similar; mild symptoms on one occasion may cause more severe symptoms at another time.
The most severe allergic reaction is anaphylaxis — a life-threatening whole-body allergic reaction that can impair your breathing, cause a dramatic drop in your blood pressure and affect your heart rate. Anaphylaxis can come on within minutes of exposure to the trigger food. It can be fatal and must be treated promptly with an injection of epinephrine (adrenaline).
Most symptoms occur within two hours of ingestion; often they start within minutes. In some very rare cases, the reaction may be delayed by four to six hours or even longer. Delayed reactions are most typically seen in children who develop eczema as a symptom of food allergy and in people with a rare allergy to red meat caused by the bite of a lone star tick.