Hypersensitivity- type I Flashcards
What is type I hypersensitivity?
Allergy
How quickly does type I hypersensitivity occur?
Immediate
Less than 30 mins
What is an example of a local reaction type I hypersensitivity?
Ingested or inhaled allergens
What is a systemic type I hypersensitivity reaction?
Insect sting or IV administration
What are the antigens in type I hypersensitivity?
Environmental
Non- infectious antigens
What are domes examples of allergens in type I hypersensitivity?
Tree and grass pollen House Dust mite Animal dander Fungal spores Insect venom Medicines Chemicals like latex Foods
What are the mechanisms that type I hypersensitivity uses?
Abnormal adaptive Immune response against the allergens e.g. T helper 2 response, IGE production
Mast cell activation- sensitised Individuals
Who is more at risk to allergies, developing countries or westernised countries?
Westernised as:
Smaller family, urban homes, intestinal microflora stable, high antibiotic use, low or absent helminth burger, good sanitation low orofaecal burden
TH2 response
Should children be exposed to microbes?
Yes as protected against allergic disease
What is the most serious type of allergy?
Anaphylaxis
Why wouldn’t a man stung by a bee have died the first time but did die the second?
Sensitised
What is dysbiosis?
Compositional and functional alterations of microbiome
What is microbiome?
The complete genetic content of all the microorganisms that typically inhabit in the body such as skin or gastrointestinal tract
What is the therapy for type I hypersensitivity?
TH2 response- allergen desensitisation
IGE- anti IGE monoclonal antibody
Anti histamine, leukotriene receptor antagonists, corticosteroids
What is immunotherapy?
Administaryionof increasing doses of allergen extracts over a period of years by injection or drops or tablets under the tongue