What is an allergy? Example of allergensAllergic symptoms Example of allergiesHow body responds to allergens?

Allergies A rapid overeaction to an antigen that is not normally harmful Allergens: substances that cause allergic reactions. Examples Pollen Insect sting Certain foodAnimal hairDustMold Body cells release runny nose swollen eyeswheezingrashcoughing INFLAMMATORY RESPONSE 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 population Slide 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 responds to allergens?