allergies Flashcards
(54 cards)
why does systemic anaphylaxis occur ?
due to a common stimuli of drugs , venom or foods
what is the route of entry ?
intravenous which can be directly or following absorption into the blood after oral intake
what can the response include
edema which is swelling , increased vascular permeability and laryngeal edema , circulatory collapse and death
what is acute urtucaria also known as?
wheal and flare
why does this occur ?
due to a common stimuli of past viral , animal hair , bee stings and allergy testing.
what is the route of entry ?
through the skin
what can occur ?
it can be systemic
what are the symptoms ?
increased blood flow , vascular permeability and swelling
what is seasonal rhino conjunctivitis also known as?
hay fever
what is the common stimuli ?
pollen and dust mite feaces
what is the route of entry ?
contact with the conjunctiva of the eye and nasal mucosa
what is the response ?
swelling of the conjunctiva and nasal mucosa and sneezing
what is the common stimuli of asthma ?
dander from cats , pollen and dust mite faeces
what is the route of entry ?
inhalation which leads to contact with muscosal of the lower airways
what is the response ?
bronchial constriction , increased mucus production and airway inflammation
what are the common stimuli of food allergy?
peanuts , shellfish , milk eggs and wheat
what is the route of entry for food allergies ?
oral
response ?
vomitting , diarrhoea and itching
what is pruitis ?
itching
what is IgE a prominent defense against ?
extracellular pathogens such as parasitic organisms like protazoans
what are the immediate hypersensitivity reactions involve ?
they are caused by the activation of mast cells and basophils as a result of IgE cross binding to the innocuous antigen.
what is sensitisation involve ?
the class switching to IgE production on the first contact with an allergen.
what are the common sensitising agents ?
proteases
what does the enzyme Der p 1 do ?
it cleaves the occludin in tight junctions and it enters the mucosa , it is then taken up by dendritic cells for antigen presentation and Th2 priming. The dendritic cell prime the T cells in the lymph and Th2 induces B cell switch to produce IgE. The plasma cell then travel back to the mucosa and produce Der p 1 specific IgE antibodies. The IgE binds to the FcERI receptor on mast cells. The Der p 1 specific IgE binds to the mast cells and this triggers degranulation. This leads to allergic symptoms.