Clinical Features of Asthma

Question 1

Asthma

Answer 1

Characterised by increased responsiveness of the trachea and bronchi to various stimuliand manifested by a widespread narrowing of the airways that changes in severity either spontaneously or as a result of therapy
Reversible airflow obstruction

Question 2

Pathophysiology of asthma

Answer 2

Airway inflammation mediated by the immune system
Widespread narrowing of airways
Increased airway reactivity

Question 3

Proven risk factors for asthma

Answer 3

Genetic - atopy
Occupation
Smoking

Question 4

Genetic risk factors for asthma

Answer 4

Atopy - inherited tendancy to IgE response to allergens

Strongest risk factor: personal, familial atopic tendancy (mother 3x more influencial than father)

Question 5

Asthma risk from smoking

Answer 5

Maternal smoking during pregnancy - decrease in FEV1
Increased wheezy illness
Increased airway responsiveness
Increased severity

Question 6

Possible risk factors for smoking

Answer 6

Reduced exposure to microbes/microbial products - children brought up on farms less likely to develop asthma
Indoor pollution, chemical household products

Question 7

Environmental allergens and asthma/atopy

Answer 7

House dust mite
Cat
Grass pollen

Question 8

Diagnosis of asthma

Answer 8

Wheeze
Shortness of breath
Tightness of chest
Paroxysmal, usually dry cough
Occasional sputum

Question 9

Variable symptoms

Answer 9

Triggers - Exercise, cold air, perfume, pets, URTI’s, smoke, trees, grass pollen, food, aspirin

Question 10

Investigations

Answer 10

Chest x-ray - hyperinflated, hyperlucent
Skin prick testing/total and specific IgE - atopic status
Full blood count - eosinophilia (atopy)

Question 11

Acute severe asthma (objective assessment)

Answer 11

Ability to speak
Heart rate
Respiratory rate
Peak expiratory flow (PEF)
Oxygen saturation/arterial blood gases