Environmental influences of the lung

Question 1

What is FeNO

Answer 1

• Exhaled nitric oxide or (eNO)

Question 2

Why is FeNO important?

Answer 2

• Simple measure of nitric oxide in exhaled breath
• Simple machines able to do this
• Measured in ppb
• Generally increased in asthma
• Not ‘diagnostic’
  (High >50ppb, normal <25ppb)

Question 3

What is asthma?

Answer 3

Common chronic inflammatory disease of the airways characterised by variable and recurring symptoms, reversible airflow obstruction and bronchospasm

Question 4

What are some common symptoms of asthma?

Answer 4

• Wheezing
• Coughing
• Chest tightness
• Shortness of breath

Question 5

What are some environmental influences of asthma?

Answer 5

Pollens, infectious agents, fungi, pets, animals, air pollution

Question 6

What are some occupational influences of astham?

Answer 6

flour, car spray paints, resins, cleaning agents, laboratory animal workers, wood dust

Question 7

Who has asthma?

Answer 7

• 5-16% of people worldwide
• Wide variation between countries
• Increase in prevalence second half of the 20th century
  Now plateaued mostly
• US study; Poorer individuals, African-Americans
• Many studies identify a wide range of risk factors
• Hygiene hypothesis, Berlin

Question 8

What is the hygiene hypothesis?

Answer 8

Early childhood exposure to particular microorganisms protects against allergic diseases by contributing to the development of the immune system

Question 9

What is the link between farm life and asthma?

Answer 9

• Farm life protected the subsequent development of asthma
• Early and in utero life seem to have an important role
  -Specific agents not identified, but likely to be a mix of bacterial and other agents, potentially altering gastrointestinal immune response
• Airway bacteria may also play a role in causing asthma, role of rhinovirus

Question 10

What is the link between cat ownership and asthma?

Answer 10

• Cat ownership and exposure most implicated
• Exposure at home is associated with sensitisation as judged by IgE, but;
• Timing and intensity to pet exposures appear important

Question 11

What is PM2.5 and PM10?

Answer 11

PM = Particulate matter
2.5 and 10 relates to diameter
Air pollution; aggravating lung diseases;
Responses to pollutants can be analogous to viral responses
Asthma hospitalisations relate to PM2.5 and PM10
- More association with it causing asthma not just aggravating it

Question 12

What are high molecular weight agents as a cause for asthma?

Answer 12

Grain
Wood
Animals, fish
Latex

Question 13

What are low molecular weight agents as a cause for asthma?

Answer 13

Glutaraldehyde
Isocyanates
Paints
Metal working fluids
Metals

Question 14

What is hypersensitivity pneumonitis?

Answer 14

Is an inflammation of the alveoli within the lung caused by hypersensitivity to inhaled agents
(not asthma)
- Immune response 3 + 4

Question 15

What are the different forms of hypersensitivity pneumonitis?

Answer 15

Acute, sub acute and chronic forms (fibrotic, non fibrotic)
Immune complex related disease
Antigen reacts with antibody
Normally IgG response

Question 16

What are the environmental influences of hypersensitivity pneumonitis?

Answer 16

Very significant environmental influences; farmers lung, bird fanciers lung, metal working fluids

Question 17

What is hot tub lung?

Answer 17

Hot Tub Lung is caused by a bacteria called Mycobacterium avium, that is sometimes found in hot tubs. It is inhaled with the hot tub steam and can get into the lungs of swimmers.
Hot tub use in general identified as a cause of EAA

Question 18

Why are hobbies important when taking a history?

Answer 18

• Patients won’t tell you themselves as they won’t think it is relevant
• Can be the reason e.g. farm animals, trombone

Question 19

What is COPD?

Answer 19

Chronic obstructive Pulmonary Disease

is a type of obstructive lung disease characterized by chronically poor airflow. It typically worsens over time, with the main symptoms include: shortness of breath, cough, and sputum production

Question 20

What are the causes of COPD?

Answer 20

Tobacco smoking main cause
Other causes include occupational exposures such as;
Silica, Coal, Grain, Cotton, Cadmium
PAH, Isocyanates, Iron/steel processing, Agricultural dust, biomass fuels, Wood dust