What is an allergic reaction?

An allergic reaction is the body's immune system responding to a substance (allergen) as if it were a harmful pathogen, such as a virus or bacterium. In individuals with allergies, the immune system mistakenly identifies certain harmless substances as threats and releases chemicals, such as histamines, to defend against them. These chemicals lead to various symptoms, ranging from mild to severe.

Common allergens include pollen, dust mites, animal dander, certain foods (e.g., nuts, shellfish), insect stings, medications, and latex. When a person with an allergy comes into contact with an allergen, the immune system triggers an allergic reaction. Symptoms can include sneezing, itching, hives, swelling, runny or stuffy nose, gastrointestinal issues, and in severe cases, anaphylaxis, a life-threatening reaction that requires immediate medical attention.

Allergic reactions can vary widely among individuals, and the severity of symptoms may depend on factors such as the person's sensitivity to the allergen, the amount of exposure, and the route of exposure (e.g., ingestion, inhalation, skin contact). It's important for individuals with known allergies to identify and avoid their specific triggers and, if necessary, to have access to appropriate medical treatments such as antihistamines or epinephrine for severe reactions.