Asthma

Question 1

What are the three aspects of the asthma triad?

Answer 1

1. Reversible airway obstruction
2. Airway inflammation
3. Airway hyperresponsiveness

Question 2

Explain the dynamic evolution of asthma

Answer 2

Bronchoconstriction –> brief symptoms
Chronic airway inflammation –> exacerbations AHR
Airway remodelling –> fixed airway obstruction

Question 3

Give hallmarks of remodelling in asthma

Answer 3

Te epithelium takes on an unorderly appearance
Thickening of the basement membrane
Collagen deposition in the submucosa
Hypertrophy of the smooth muscle
Desquamation and eosinophils present in the cells lining the airways

Question 4

What is the inflammatory cascade in asthma?

Answer 4

Genetic predisposition + trigger factor
Airway inflammation
Mediators/TH2 cytokines
Twitchy smooth muscle

Question 5

What drugs are able to normalise the unorderly structure of an asthmatic airway?

Answer 5

Glucocoticoids

Question 6

List some clinical aspects of asthma

Answer 6

Episodic symptoms and signs
Diurnal variability
Non-productive cough
Triggers
Associated atopy
Family history of asthma
Wheezing due to turbulent airflow

Question 7

What methods are used in the diagnosis of asthma?

Answer 7

Clinical history and examination
Diurnal variation of peak flow rate
reduced forced expiratory ration (FEV1/FVC) < 75%
Reversibility to inh. salubutamol (>15%)
Provocation testing - bronchospasm (exercise and histamine/allergen inhalation)

Question 8

Define bronchial asthma

Answer 8

It is a chronic inflammatory disorder characterised by hyperreactive airways leading to episodic reversible bronchoconstriction

Question 9

What is extrinsic asthma?

Answer 9

Asthma triggered by an inhaled antigen

Question 10

What is intrinsic asthma?

Answer 10

Asthma triggered by non-immune mechanisms - chemical induced and exercise induced asthma

Question 11

What types of hypersensitivity reaction is asthma?

Answer 11

Type I hypersensitivity reaction (allergen binds to igE on surface of mast cells)