Type 1 rapid hypersensitivity reactions
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Called atopic allergy
o Most common type of allergy
Caused by:
o Increased production of immunoglobulin E (IgE) antibody-antigen exposure
Acute inflammation occurs
o Causing the release of histamine and other vasoactive amines from:
 Basophils
 Eosinophils
 Allergic asthma
 Hay fever
 Allergic rhinosinusitis
 Allergies
 Latex
 Bee venom
 Peanuts
 Iodine
 Shellfish
 Medications
 Etc.
The first exposure results in the formation of IgE which attaches to a mast cell causing it to
differentiate.
When a sensitized patient is re-exposed a reaction occurs.
o Type 1 hypersensitivities can happen on the first contact but often happen on
subsequent exposures.
Allergens are contacted by:
o Inhalation
 Pollen
 Spores
 Animal dander
 Dust
o Ingestion
 Foods
 Food additives
 Drugs
o Injection
 Insects
 Drugs
o Contraction/contact
 Latex
 Food
 Environmental proteins
Some reactions occur only in areas of antigens exposure.
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Such as
 Mucus membranes
 Rhinorrhea
 Sneezing
 Itchy, red, watery eyes
Other reactions may involve:
o Blood vessels
 Causing blood vessel dilation
 Decreased cardiac output
o Bronchiolar smooth muscle
 Bronchoconstriction = anaphylaxis
Physical assessment
o Rhinorrhea
 Runny/stuffy nose
o Itchy/watery eyes
o Breathing through the mouth
o Nasal sound to voice
o Nasal mucosa is swollen and pink
o Headache or pressure in sinuses
o Postnasal drip=dry scratchy throat
o Fever is rare (associated with bacteria infection)