Allergy

Definition

An allergy is an exaggerated immune response to a substance that is typically harmless to most people. This hypersensitivity can cause various symptoms, from mild irritation to severe reactions.

5 Must Know Facts For Your Next Test

1. Allergens are substances that trigger allergic reactions, such as pollen, pet dander, or certain foods.
2. Immunoglobulin E (IgE) antibodies play a crucial role in allergic reactions by binding to allergens and triggering histamine release.
3. Histamine release from mast cells and basophils leads to inflammation and common allergy symptoms like sneezing, itching, and swelling.
4. Common treatments for allergies include antihistamines, corticosteroids, and immunotherapy (allergy shots).
5. Anaphylaxis is a severe, life-threatening allergic reaction that requires immediate medical attention and treatment with epinephrine.

Review Questions

• What role do IgE antibodies play in allergic reactions?
• What are some common symptoms of an allergic reaction?
• How does histamine contribute to the symptoms of allergies?

Related terms

Mast Cells: Immune cells that release histamine and other chemicals during an allergic reaction.

Antihistamines: Medications used to treat allergy symptoms by blocking the effects of histamine.

Anaphylaxis: A severe, potentially life-threatening allergic reaction characterized by difficulty breathing, low blood pressure, and loss of consciousness.