7.2 Allergies Flashcards
What is the sensitisation phase in allergies?
The first encounter with the antigen
What is the effector phase in allergies?
Clinical pathology upon re exposure to the same antigen as in the sensitisation phase
What is a type I hypersensitivity reaction?
Immediate,
What is a type II hypersensitivity reaction?
Antibody mediated over 5-12 hours
What is a type III hypersensitivity reaction?
Immune complex mediated over 3-8 hours
What is a type IV hypersensitivity reaction?
Cell mediated caused by infectious agents over 24-48 hours
List 3 risk factors of getting allergic disorders?
High antibiotic use
Low Helminth burden
Westernised country
Good sanitation
What increased immunoglobulin causes hypersensitivity reactions?
IgE
Give examples of three common allergens
House dust
Animals
Pollen
Insect venom
What is the cell responsible for hypersensitivity reactions?
Mast cells
What do mast cells release in hypersensitivity reactions?
Histamine and chemokines
What skin problems can result from hypersensitivity reactions?
Urticaria- rash from mast cells in the epidermis
What do mast cells in the deep dermis cause in hypersensitivity reactions?
Angioedema in the lips, eyes, tongue and upper respiratory airway
What is anaphalyaxis?
Systemic activation of mast cells causing hypotension, CV collapse, generalised urticaria, angioedema and breathing problems
How can anaphylaxis be treated?
Give epinephrine intramuscularly to reduce effects
