Anaphylaxis

Definition

Anaphylaxis is a severe, potentially life-threatening allergic reaction that can occur rapidly after exposure to an allergen. It involves multiple organ systems and requires immediate medical attention.

5 Must Know Facts For Your Next Test

1. Anaphylaxis involves the release of large amounts of histamine and other inflammatory mediators from mast cells and basophils
2. It can cause symptoms such as difficulty breathing, hives, swelling, low blood pressure, and gastrointestinal symptoms
3. Common triggers include foods (like peanuts), insect stings, medications, and latex
4. Epinephrine is the first-line treatment for anaphylaxis; it works by constricting blood vessels and opening airways
5. A biphasic reaction can occur in which symptoms return hours after the initial episode without further exposure to the allergen

Review Questions

• What are the primary immune cells involved in anaphylaxis?
• List at least three common triggers of anaphylaxis.
• What is the first-line treatment for anaphylactic reactions?

Related terms

Hypersensitivity:

Exaggerated immune response to an antigen leading to tissue damage or disease

Mast Cells:

Immune cells that release histamine and other substances during allergic reactions

Epinephrine: A hormone and medication used as a first-line treatment for severe allergic reactions