-Immediate

-Allergic reactions

-IgE mediated

-Helper T cells (Th2), mast cells and basophils

-Mast cells and basophilsrelease histamine as granules in response to antigen

-5 minutes to 1 hour for response

-Causes vasodilation, increased blood vessel permeability, and vascular leakage

-2-8 hours to several days later

-Eosinophils brought to area

-Lipid mediators brought to area: leukotrienes, prostaglandins, arachadonic acid

-Inflammation and tissue destruction occur

-Chemotactic factors are used

-Atopic person is prone to allergies

-High IgE levels

-Th2 cells produce more IL-4

-Specific gene information

-Positive family history

-Life-threatening medical emergency

-Serious symptoms: respiratory distress, laryngeal edema, hypotension, arrythmias

-Triggered by small doses of antigen

-Treatment: antihistamine