1.1 airway remodelling + development + triggers

airway remodelling is the result of chronic biochemical pro inflammatory processes in the air ways

that results in a chronic thickening of the airway walls and restriction of airflow, which will progressively become harder to treat

Changes occur in airways following:

• chronic and repeat exposure to triggers display increased blood flow due to novel vascularisation (angiogenesis),

• an altered epithelial barrier presenting with a greater chance of shedding

• and increased mucus producing cells (goblet cell hyperplasia)

Frequent inflammatory episodes also thicken the basement membrane

narrowing the airway and reduce airway flexibility through fibrosis.

Airway remodelling occurs when bronchial epithelial cells transition into mesenchymal

increasing the smooth muscle content

Epithelial cells lose their cell adhesion

and functional polarity with tight junctions.

Additionally, eosinophils can further exacerbate airway remodelling

due to their release of TGF-B and cytokines by interactions with mast cells.

These mechanisms of airway remodelling may worsen inflammation

and aggravate asthma over time if not treated and managed correctly.

Asthma is a multi factorial disease which involves both a genetic and environmental component.

Both components inform each other

This complex inter-relationship translates into the many sub-types of asthma we observe in clinic

Briefly, some known causes for asthma include

Briefly, some known causes for asthma include

genetics

living environment

exposure

events in early life

physical factors

• Genetics -

• Family history of atopic disease, i.e. asthma, allergic rhinitis (hayfever), allergic dermatitis (eczema).

• Your living environment

• , such as urbanisation,

• diet,  

• work stress etc,

• the hygiene hypothesis .

• Exposure to air-borne environmental irritants

• , e.g. house dust mites,

• mould,

• pollen,

• and ingested allergens, e.g. aspirin.

• Events in early life

• , e.g. low birth weight,

• exposure to smoke,

• prematurity,

• viral infections

• Physical factors

• - those who are overweight or obese are at greater risk of asthma.

asthma triggers

viral

environment

pharmacuteics/cosmetics

indorr pollutants

animal

• Viral -  

• Rhinovirus,

• Respiratory Syncytial Virus

• , Adenovirus.

• asthmatics appear to be less vulnerable to COVID-19 infections.

• Environment -

• Changes in the weather (cold air),

• humidity

• Pharmaceutics/Cosmetics -

• Aspirin,

• Perfume,

• Body sprays/deodorants

• Indoor pollutants -

• Cigarette/Cigar smoke,

• Vaping,

• Wood smoke,

• House Dust Mite,

• Cleaning materials

• Animals -

• animal fur/dander,

• feathers