Chapter 21 Allergy and Anaphylaxis Terms

Allergen

A substance that causes an allergic reaction

Allergic reaction

The body's exaggerated immune response to an internal or surface agent

Anaphylaxis

An extreme, life-threatening, systemic allergic reaction that may include shock and respiratory failure

Angioedema

Localized areas of swelling beneath the skin, often around the eyes and lips, but can also involve other body areas as well

Envenomation

The act of injecting venom

Epinephrine

A substance produced by the body (commonly called adrenaline), and a drug produced by pharmaceutical companies that increases pulse rate and blood pressure; the drug of choice for an anaphylactic

Histamines

Chemical substances released by the immune system in allergic reactions that are responsible for many of the symptoms of anaphylaxis, such as vasodilation

Immune response

The body's response to a substance perceived by the body as foreign

Immune system

The body system that includes all of the structures and processes designed to mount a defense against foreign substances and disease-causing agents

Immunology

The study of the body's immune system

Leukotrienes

Chemical substances that contribute to anaphylaxis; released by the immune system in allergic

Stridor

A harsh, high-pitched respiratory sound, generally heard during inspiration, that is caused by partial blockage or narrowing of the upper airway; may ne audible without a stethoscope

Toxin

A harmful substance produced by living cells or organisms

Urticaria

Small areas of generalized itching and/or burning that appear as multiple raised areas on the skin; hives

Wheal

A raised, swollen, well-defined area on the skin resulting from an insect bite or allergic reaction

Wheezing

A high-pitched, whistling breath sound that is most prominent on expiration and which suggests an obstruction or narrowing of the lower airways; occurs in asthma and bronchiolitis