ALLERGY
Allergy is a condition of exaggerated sensitivity to any
one of
several substances which ordinarily are considered harmless.
Allergies were first noted and recorded as reactions exhibited
toward certain foods. Later it was recognized that an allergy
may be caused by a variety of agents such as bacteria, drugs,
food, animals, plants, and hormones, which have been admin-
istered, contacted, or inhaled. Some cases of migraine,
peptic
ulcer, and colitis appear to be due to allergies. Some
people
become allergic to sunlight, cold or the toxins of bacteria
in
their own bodies. It is estimated that 25% of people
are
allergic, in some degree, to one or more substances.
The allergic reaction is similar to other antigen-antibody re-
actions. In other words, some "foreign" substance (allergen)
stimulates the production in the body of antibodies that make
the individual sensitive to subsequent contact with that sub-
stance. Many of the substances that cause allergy are proteins.
Common allergens of animal origin are feathers, fur, and wool.
Common plant allergens are pollens and molds.
(((((((( Anaphylactic Shock ))))))))
Is a particularyly violent form of allergy, and is caused by the
injection of an allergen directly into the blood stream.
Anaphylaxis rarely if ever occurs without previous sensitization.
Thus, a first injection of an antitoxin containing horse serum
may be entirely harmless, whereas a second injection of
identical material might prove fatal.
((Histamine/Antihistamine))
Some types of allergy appear to be connected to the secretion
of a substance called "histamine", and the symptoms can
often be relieved by drugs which counteract it.
****Antihistamines****
HISTAMINES/ANTIHISTAMINE DRUGS
Histamine is important as a drug and also as a suspected “villain” of various allergic condition such as hives,
asthma, hay fever, and serum sickness. Histamine (C5H9N3) is a decomposition product of histidine( one of the essential Amino
Acids) and is normally present in many animal and Human tissues. Also present in the tissues is an enzyme (histaminase) that
acts, though exceedingly slowly , to destroy histamine.
