Asthma

Question 1

What is asthma?

Answer 1

Asthma is a chronic disease in which there is a reversibly obstruction of the airways in response to a stimulus and usually involves hyper-reactivity.

Question 2

What is the difference between extrinsic and intrinsic asthma?

Answer 2

Extrinsic asthma has an external cause - allergen - and tends to start in childhood and show the development of IgE antibodies.

Intrinsic asthma has no apparent external cause, is more common in adults and is IgE-independent

Question 3

What are the symptoms of asthma?

Answer 3

Shortness of breath(on exposure to allergen, cold air, tobacco smoke etc.)
Tightness in chest
Wheezing (typically expiratory - continuous high-pitched musical sound)
Cough (often present at night and on exposure to allergen, cold air, tobacco smoke etc.)
Nasal polyposis (swelling of nasal lining)

Question 4

What are the causes of asthma?

Answer 4

Narrowing of the airways is caused by:
Bronchoconstriction
Inflammtion (oedema and increased production of mucous)

Question 5

What are strong risk factors of asthma?

Answer 5

Smoking
Genetic factors (family history of atopic disease)
Exposure to allergens
History of atopic disease

Question 6

Give examples of disease considered to be atopic diseases

Answer 6

Eczema

Allergic rhinits

Question 7

What are the weak risk factors of asthma?

Answer 7

Nasal polyposis
Obesity
Gastro-oesophageal reflux
Sex - boys tend to grow out of asthma

Question 8

What are common triggers of asthma?

Answer 8

House dust mites
Pollen
Exercise
Stress
Animal dander
Aspirin and NSAIDs

Question 9

What cell drives the inflammatory component of asthma?

Answer 9

Th2 lymphocytes

Question 10

Type one hypersensitivity is typically the immediate asthma response. What occurs in this response?

Answer 10

Antigen/IgE insuced mast cell degranulation results in the release of histamine, prostaglandin D2 and leukotriene C4 and D4

These cause bronchoconstriction, increased mucous production and vascular leak

Question 11

What happens to the smooth muscle of the airways in patients with asthma?

Answer 11

There can be hyperplasia of the smooth muscle of the airways and also the muscle changes function slightly, so that it can contract more easily

Question 12

What is usually the first initial test for asthma?

Answer 12

Spirometry - peak expiratory flow

Question 13

By how much should a patient’s FEV1/FVC increase after taking bronchodilators?

Answer 13

12%

Question 14

How is taking PEFR everyday, long-term helpful for asthma patients?

Answer 14

It allows early detection of changes in disease state that require treatment and allows evaluation of responses to changes in therapy.

Question 15

Other than PEFR, what other test can indicate asthma?

Answer 15

Positive skin tests
Blood eosinophil level above 4%
Raised specific IgE to allergen

Question 16

What is a SABA?

Answer 16

A short acting beta agonist that is the first line of asthma treatment and is taken by the patient up to four times a day as and when they need it

Question 17

What are the features of an acute severe asthma exacerbation?

Answer 17

PEFR 33-50%
Respiratory rate over 25 breaths per min
Heart rate over 110beats per minute
Unable to complete sentences

Question 18

What are the features of a moderate asthma exacerbation?

Answer 18

Symptoms

PEFR 50-75%

Question 18

What are the features of a life threatening asthma exacerbation?

Answer 18

PEFR less than 33%
Oxygen saturation less than 92%
Silent chest
Normal blood gases
Poor respiratory effort
Exhaustion
Cyanosis
Arrythmia
Reduced GCS