L 12,13,14 Allergic Rhinitis Flashcards
What is atopy?
A genetic predisposition to hypersensitivity or allergy.
What is Oedema?
Swelling of soft tissue
What is pruritus?
Itching
Rhinitis means?
Inflammation
Rhinorrhoea means?
Runny Nose
What is an allergy?
immune response to a foreign substance or allergen.
for some people it is not harmful as it makes an immune response but for some people it overreact and cause problems.
Allergic rhinitis can be split into 3 categories:
Seasonal allergic rhinitis
Perennial allergic rhinitis
Non-allergic rhinitis
Is hayfever well diagnosed by health professionals?
No, usually it is overlooked and diagnosed as a cold or asthma.
What are the 2 stages of asthma? + brief explanation
Sensitisation - antigen binds and mounts an immune response with IgE antibodies. Bind to the immune and mast cells to prime them for re-exposure.
Re-exposure - being exposed to the antigen again, and a full immune response occurring due to IgE antigen-antibody complex activating mast cell degranulation
Early phase symptoms of allergic rhinitis
Sneezing
Nasal itching
Rhinorrhoea
Nasal congestion
What are the Early phase symptoms of allergic rhinitis
Early phase symptoms occur within minutes.
Histamine released by mast cells binds to receptors all over body, causing vasodilation and leaky blood vessels.
Interstitial fluid then leaks in = nasal congestion.
Histamine binding also causes increased mucus production (runny nose) and also binds to sensory nerve receptors for sneezing and itching to occur.
Late phase symptoms occur within…. due to
Late phase symptoms occur within 6-12 hours.
Antigen stimulates T&B cells which stimulate mast cells to release cytokines, causing stimulatory cascade to release other mediators.
These other mediators increase dilation and decrease emptying = nasal congestion/obstruction and nasal hyperactivity
What are the 4 strategies to address symptoms of allergic rhinitis?
- Avoid triggers
- Block histamine action via antihistamines and anticholinergics
- Prevent mast cell release via mast cell stabilisers
- Prevent inflammation via corticosteroids.
Which histamine receptor are we most concerned with? What type of receptor is it?
H1 histamine receptor, GPCR
What are the strategies of treating allergic rhinitis?
Symptoms relief
Avoid triggers
With medicine
What type of drug are antihistamines?
Histamine antagonist.
Antihistamines are a class of drugs commonly used to treat symptoms of allergies.
These drugs help treat conditions caused by too much histamine, a chemical created by your body’s immune system.
Antihistamines are most commonly used by people who have allergic reactions to pollen and other allergens