Allergy Flashcards
what is hypersensitivity?
an immune response that causes collateral damage to self
usually an exaggeration of the normal immune mechanisms
what is the pathophysiological basis for allergy and autoimmunity?
hypersensitivity
when does an allergic reaction occur?
when a persons immune system reacts to a normally harmless substance
what is an allergen?
a substance that causes an allergic reaction
what type of reaction is a type I allergy?
immediate
occurs within minutes-hours after exposure to the allergen
name four routes of exposure to an allergen
ingestion
inhalation
skin contact
injection
name some local symptoms of a type I allergic reaction
itching
swelling
nausea
vomiting
name some systemic symptoms of a type I allergic reaction
airway obstruction
hives
low BP
name four things that type I allergy can present with
urticaria
angioedema
wheezing
anaphylaxis
describe urticaria
very itchy
lesions appear within an hour
lasts 2-6 hours
what are some other names for urticaria?
hives
wheals
nettle rash
what is angioedema?
localised swelling of subcutaneous tissue or mucous membranes
what is anaphylaxis?
a severe and life threatening hypersensitivity reaction
what investigations are done for a type I allergy?
history
specific IgE
skin prick test
challenge test
what is measured during anaphylaxis?
serum mast tryptase levels
