Hypersensitivity pneumonitis

Question 1

Antigens causing hypersensitivity pneumonitis

Answer 1

Farmers lung - saccharopolyposa reotivirgida
Saw mill workers lung
Bird fanciers lung - avian protein
Mushroom workers lung - themophilic actinomyecetes
Humidifier lung
Cheese washer
Suberosis
malt - aspergillus clavatus

Question 2

HS pneumonitis presentation

Answer 2

Cough + SOB
Fever, weight loss
Can -> preogressive fibrosis
More in upper lobes

Question 3

Lung sounds HS pneumonitis

Answer 3

Lung sounds - inspiratory squawk in upper zones
or crackles middle zones

Question 4

What can meausre in brid fanciers lung

Answer 4

IgG antibodies

Question 5

Treatment o HS pneumonitis

Answer 5

REMOVE antigen exposure
IMmunosupress- steroids, mycophenolate, cyclophosphamide

Question 6

Chronic treatment for chronic fibrosing lung progressive diseases

Answer 6

Nintedanib
Dexamethasone and antiIL6 drugs

Question 7

HS pneumonitis on CT

Answer 7

Ground glass
Small centrilobular nodules
Air trapping + AW limitation = AW mosaicism
Middle zones

Question 8

Type of hypersensitivity reaction -> pneumonitis

Answer 8

Immune complex mediated tissue damage - type III
delayed IV - CHRNOCI

Question 9

pROTEINS IN BIRD FANCIERS LUNG

Answer 9

avian proteins

Question 10

What causes farmers lung

Answer 10

spores of Saccharopolyspora rectivirgula (formerly Micropolyspora faeni)

Question 11

Symptoms in relation to symptoms exposure

Answer 11

Acute - 4-8 hrs after exposure
Subside in 24-48 hours
Chronic after long term low exposure

Question 12

Acute HS pneumonitis vs chronic

Answer 12

Cough (productive or non-productive)
Dyspnoea
Fever
Malaise
Chest tightness
Acute type 1 respiratory failure may develop in severe cases

Chronic - insidious
Insidious cough/dyspnoea symptoms
Weight loss
Clubbing (50% of cases)
More widespread fibrotic changes mimicking idiopathic pulmonary fibrosis

Question 13

What hear on auscultation in HS pneumonitis

Answer 13

Bilateral midzone inspiratory crepitations

Question 14

Investigations HS p

Answer 14

FBC
ABG- esp if T1RF
Serum participant antibodies
CXR, HRCT
lung function - FVC + FEV1 , DLCO
Acute= restrictive, chronic = obstructive
Broncheolar lavage - BAL - fluid for antigens

Question 15

What seen in BAL HS pneumonitis

Answer 15

Leucocytosis

Question 16

Complications pneumonitis chronic

Answer 16

Chronic oxygen requirement
Widespread fibrosis may result in chronic hypoxaemia requiring long-term oxygen therapy at home
Decreased lung function will lead to a reduced ability to carry out physical activities and activities of daily living

Question 17

What is allergic bronchopulmonary aspergillosis

Answer 17

When asperillus fumigatus colonises resp tract with compromised immunity eg atopy,asthma, CF causing AW ostruction, inflmaation, mucoid impaction -> bronchiectasis, fibrosis, AW compromise

Question 18

What investigation can help with ABPA

Answer 18

Skin test for allergic reaction to aspergillus fumigatus
IgG and IgE againtst
Eosiniphilia