Asthma Flashcards
Define ASthma
Disease characterised by an increased responsiveness of trachea & bronchi to various stimuli.
Manifested by a widespread narrowing of airways that changes in severity either spontaneously or due to therapy.
How does asthma cause the airways to narrow?
Inflammation of the airway:
- > Directly narrows the airway
- > Increases airway reactivity/irritibility which results in spontaneous or stimulus driven airway narrowing
How many people does asthma kill a year?
Around 1000
How many people are recieveing asthma treatment in the UK?
5.4 million
10-15% of kids and 5-10% adults
How many hospital admissions are astham related?
67000 + 4.1million GP consulatations
How much money is spent on asthma?
~2.3billion a year
List the proven risk factors for asthma?
- Atopy
- Occupation
- Smoking
Define atopy
An inherited tendency to produce IgE in response to allergen
What kind of conditions can becaused by atopy?
- AStham
- Eczema
- Hayfever
- Food Allergies
How do we test for atopy?
- Markers
- Skin prick test (place allergen under skin)
- IgE tests
What kind of inheritance has the main effect on atopy?
MAternal inheritence is 3x as influential as paternal inheritance when it comes to determining atopy
What kind of genes show association with atopy?
- Immune response genes (Il-4, IL-5, IgE)
- Airway genes (ADAM33)
What sort of allergens are known to be related to asthma?
House dust mite dropppings
Cat allergens
How are exposure and atopy relateD?
Exposure doesnt cause atopy or asthma.
once someone atopic is sensitized to an allergen it can trigger an asthmatic response.
How much of asthma is occupational?
Around 10-15% of adult onset asthma is occupational
What types of occupations can cause asthma?
Bakers - Grains
Lab workers - Rodent urine
Painters - PAint
Chefs/fishermen - Crustaceans
What happens to a child whose mother smokes in pregnancY?
They can develop:
- Lower FEV1
- Wheezy illness
- A greater airway responsiveness
- Greater chance & severity of asthma
What is the grandmother effect?
A child will be twice as likely to develop asthma if their grandma smoked during pregnancy (it skips a generation).
Also 1.5x more likley if their mum did and 2.5 times if both did.
How are airway obstructions related to astgma?
Someone with a localized airway obstruction like a tumour or foreign body can appear to have asthma.
What symptoms are we looking for in a history to diagnose asthma?
- Wheeze
- Short of breath (dyspnoea)
- Chest tightness & pain
- Cough (paroxysmal, sudden)
- occasional sputum
Why is simply seeing the symptoms not enough to diagnose asthma?
Theyre the same symptoms as any other respiratory disease
What beyond the symptoms do we look for to diagnose asthma?
The variability of the symptoms. Only is asthma are the symptoms mixed up and variable with time/location.
What kind of variability is there in asthma symptoms?
The symptoms can be varied due to trigers like exercisem cold air, smoke, pets or a job.
They can also vary in time such as at day or night or weekends or holidays or even seasons.
What other conditions do we look for in a hisotry to denote asthma?
Other atopic conditions like eczema or hayfever
