What is an allergy?

Example of allergensAllergic symptoms

Example of allergies How body respondsto allergens?

AllergiesA rapid overeaction to an antigen that is not normally harmfulAllergens: substances that cause allergic reactions.

Examples

Pollen Insect sting Certain food Animal hair Dust Mold

Body cells

release

runny nose swollen eyes wheezing rash coughing

INFLAMMATORYRESPONSE

Antihistamines: drugs used to counteract the effects of histamine

SYMPTOMS

HISTAMINE

Mast Cells and the Allergic Response

What is allergy?

Example of allergens

How does body respond to allergens?

Allergic symptoms

Example of allergy?

A rapid overraction to an antigen that is not normally harmful

Pollen, Mold, Dust, Certain food, Animal hair

The body cells release histamines, which cause an inflammatory response and many allergic symptoms

runny nose, swollen eyes, wheezing, rash, coughing, itching

Asthma

Allergies

The immune system helps maintain the internal dynamic equilibrium necessary for life. However, the immune system can become out of balance.

Allergic reactions result form over activity of the immune system. The body responds inappropriately to common substances such as dust, mold, pollen, or certain foods. Antigens that cause allergic reactions are called allergens.

The immune system begins making a special type of antibody to these substances, which under normal conditions would not stimulate the immune system.

These antibodies cause cells in the body to release histamines, which cause many allergic symptoms, such as extra fluid in the nasal pathways, difficulty breathing, or inflammation. Allergies are often treated with antihistamines, drugs that stop the release of histamine.Some allergic reactions can create a dangerous condition called asthma. Asthma is a chronic respiratory disease in which the air passage become narrower than normal.

This narrowing of the air passage causes wheezing, coughing, and difficulty in breathing. Many factors, including both heredity and environment, play a role in the onset of the symptoms of asthma.

Asthma attacks can be triggered by respiratory infections, exercise, emotional stress, and certain medications, cold air, pollen, dust, tobacco smoke, pollution, etc..

Allergies – 10% of US populationAllergies – 10% of US population

Slide 12.28

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Many small molecules (called haptens or incomplete antigens) are not antigenic, but link up with our own proteins

The immune system may recognize and respond to a protein-hapten combination

The immune response is harmful rather than protective because it attacks our own cells

What is an allergy?

Example of allergens Allergic symptoms

Example of allergies How body respondsto allergens?