Case Launch (29/01)

Question 1

LO’s

Answer 1

1. Describe the aetiology/ cause, pathogenesis/ development and morphological/ structural features of asthma.
2. Describe the link between occupation, the environment and recreational pursuits in different lung diseases.

Question 2

What is bronchiolitis, and what causes it?

Answer 2

• Bronchiolitis is blockage of the small airway in the lungs due to a viral infection.
• It usually only occurs in children less than two years of age.
• Bronchiolitis is usually the result of infection by respiratory syncytial virus (72% of cases) or human rhinovirus (26% of cases).
• Supportive care at home is generally sufficient.
• Occasionally hospital admission for oxygen, support with feeding, or intravenous fluids is required.

Question 3

Define Atopy

Answer 3

• Genetic predisposition to allergic diseases (run in family).
• The triad: asthma, eczema and hayfever.

Question 4

Differnces between URTI and LRTI?

Answer 4

• URTI: runny nose, sore throat, sneezing, cough, fever, tired. If listen to chest, it is clear.
• LRTI: have productive cough, and can hear wheeze on uscultation.

Question 5

Prevalence of asthma?

Answer 5

• 10- 15%
• More common in Western countries. Maybe due to the ‘hygiene hypothesis’ children live sterilised lives and become hypersensitised to pathogens.
• Most common cause of chronic respiratory disease in the UK.

Question 6

What happens to the airways in an asthma attack?

Answer 6

1. The airways constrict, due to smooth muscle contracting.
2. More difficult to get air in and out.
3. Air trapped in the alveoli, can’t get out.
4. Even when not in an asthma attack, the asthmatic’s airway is thicker and more inflamed, than a normal airway.

Question 7

What causes asthma attacks?

Answer 7

• Exercise
• Dust
• Allergens
• Aerosols
• Damp
• Smoke
• Pollen
• Pets
• Viruses
• Cold Air

Question 8

Why are asthmatics more likely to get RTIs?

Answer 8

If have asthma attacks, the epithelium gets damaged. In respiratory tract, breathe in air so susceptible to infection, this means more likely to get RTIs.

Question 9

Which occupations are at risk for lung diseases?

Answer 9

• Wherever there is ‘particulate matter’.
• The finer the paricles, the more damage, as if they are small, they can get down to the alveoli which are easily damaged.
• Most occupational lung diseases are caused by repeated, long-term exposure, but even a severe, single exposure to a hazardous agent can damage the lung.
• Are preventable by wearing face mask, and avoiding exposure.
• Not as bad when not working (weekends and holidays).
• Eg:
  
  • Asbestos
  • Pollen
  • Coal
  • Silica
  • Dust
  • Ashes

Question 10

Describe the pathogenic changes in asthma

Answer 10

1. Antigen like pollen, binds to two IgE on the mast cells in the airway.
2. The mast cell degranulates, so releases histamine.
   
   • This causes a decrease in cAMP, so contracts smooth muscle. This leads to hypertrophy, so the asthmatic airway contracts too forcefuly.
   • This makes the capillaries more permeable, causing oedema, this is why the asthmatic airway is thicker.
3. The smooth muscle also is hypersensitive to antigens.
4. The respiratory epithelium has metaplasia/ abnormal changes. There are more goblet cells, and more mucas produced.
5. The airway is thicker due to oedema and infiltration by eosinophils and lymphocytes.