ALLERGIES IN THE “ALLERGIC” PERSON,
WHO HAS EXCESS IGE ANTIBODIES
• Some people have an “allergic” tendency.
• Their allergies are called atopic allergies b/c they are caused by a
nonordinary response of the immune system.
• Allergic tendency is genetically passed from parent to child
characterized by large quantities of IgE antibodies in the blood.
• These antibodies are called reagins.
• When an allergen enters the body, an allergen-reagin reaction takes
place allergic reaction occurs.
• IgE antibodies (the reagins) has a strong property to attach to mast cells
• Single mast cell or basophil can bind as many as half a million molecules
of IgE antibodies.
• When (an allergen) that has multiple binding sites binds with several IgE
antibodies attached to a mast cell or basophils, immediate change in
the memb of the mast cell or basophil.
• Many of the mast cells and basophils rupturerelease special
• Slow-reacting substance of anaphylaxis
• (which is a mixture of toxic leukotrienes),
• Eosinophil chemotactic subt,
• Neutrophil chemotactic subt ,
• Heparin,& platelet activating factors
• These substance cause such effects:
• Dilation of the local blood vessels;
• Attraction of eosinophils and neutrophils to the reactive site;
• Increased permeability of the capillaries
• Contraction of local smooth muscle cell.
• When a specific allergen is injected directly into the
circulation, react with basophils & mast cells
• Widespread allergic reaction occurs throughout the vascular
syst & closely associated tissues. This is called anaphylaxis.
• Histamine is released into the circulation causes
• body-wide vasodilation
• increased permeability of the capillaries with resultant marked
loss of plasma from the circulation.
• An occasion person dies of circulatory shock within a few min unless treated
with epinephrine to oppose the effects of the histamine.
• From the activated basophils and mast cells is a mixture of leukotrienes called
slow-reacting subt of anaphylaxis.
• Leukotrienes can cause spasm of the smooth muscle of the bronchioles,
eliciting an asthma-like attack, causing death by suffocation.
• Antigen entering specific skin areas and causing localized
• Histamine released locally causes
• (1) vasodilation that induces an immediate red flare
• (2)increased local permeability of the capillaries
leads to local circumscribed areas of swelling of the
• Swellings are commonly called hives.
• Administration of antihistamine drugs to a person before
exposure will prevent the hives.
• Allergen-reagin reaction occurs in the nose.
• Histamine released causes local intranasal vascular dilation
increased capillary pressure & increased capillary permeability.
• Cause rapid fluid leakage into the nasal cavities and deeper tissues
of the nose nasal linings become swollen and secretory (allergic
• Antihistamine drugs can prevent this swelling reaction.
• Other products of the allergen reagin reaction cause irritation of the
nose sneezing syndrome.
• Asthma often occurs in the “allergic” type of person allergen-
reagin reaction occurs in the bronchioles of the lungs product
released from the mast cells is slow-reacting substance of
anaphylaxis, causes spasm of the bronchiolar smooth
• Person has difficulty in breathing until the reactive products of
the allergic reaction have been removed.
• Administration of antihistaminics has less effect on the course of
asthma because histamine does not appear to be the major
factor eliciting the asthmatic reaction.
• 20 Carbon containing fatty acids derivatives of A,B,C,D and E types.
• Produce tremendous of smooth muscles of pulmonary airways leading to bronchospasm .
• Leukotrienes C4, D4, E4 represent the slow reacting substance of anaphylaxis.