allergy in the lung

Question 1

define an allergy

Answer 1

a damaging immune response by the immune system to a foreign particle, commonly a dust or pollen, to which it has become hypersensitive. Immune system-mediate intolerance

Question 2

what are the three main components of asthma (definition)

Answer 2

reversible/variable airflow obstruction
airway inflammation
hyper-responsiveness

Question 3

give the pathological findings in asthma

Answer 3

inflammation, thickened BM, airway smooth muscle hypertrophy

mast cells invading into the smooth muscle of the airway

Question 4

how should asthmas syptoms/episodes be described

Answer 4

episodic, triggered and variable. Should show a paroxsymal patterm.
Patients often have a diurnal pattern leading to nocturnal wakening

Question 5

how do you define astham on bronchial hyper-sensitivity testing

Answer 5

a drop of 20% or more in the FEV1 when patient is given metacholine or histamine.

Question 6

what degree of improvement do you need to demonstrate in the FEV1 after giving a nebuliser of salbutamol

Answer 6

15% improvement or more

Question 7

describe hypersnsitive pneumonitits (EEA)

Answer 7

inflammation of the alveoli within the lung caused by hypersensitivity to inhaled organic dusts.
have diffuse inflammation of the interstitial lung, terminal bronchioli and alveoli due to repeated inhalation fo the allergen. Systemic disease but associated with the lung due to the effects of the immune complexes being predominantely here.
Acute - 4-6 hours after exposure. Wheeze, cough, fever, chills, headache, myalgia, malaise. CHronic diseae is characterised by poorly formed non-caseating interstitial granulomatous ad mononuclear cell infiltration in a peri-bronchial distribution with prominent giant cells.
Chronic - type IV mediated. Inflammation leads to formation of non-caseating granulomas and with time the fibrosis of the alveoli.

Question 8

name the characteristic feature of hypersensitive pneumonitis

Answer 8

honeycombing.

Question 9

how would you treat someone with hypersensitive pneumonitis

Answer 9

avoid trigger, corticosteroids (can help with acute symptomatic relief and ma accelerate initial recovery in severe disease), ocygen supplementation.