Pleural effusion and interstitial lung disease

Question 1

Define ILD

Answer 1

Disease affecting the tissue and space between the alveoli (interstitium):
- Alveolar epithelium
- Pulmonary capillary endothelium
- Basement membrane
- Perivascular and perilymphatic tissue.

Question 2

Causes of ILD

Answer 2

Idiopathic pulmonary fibrosis

Connective tissue/ AI disease

Environmental exposure to toxins/ antigens

Infection

Drugs

Question 3

Upper zone causes of ILD [APENT)

Answer 3

A PENT

A- Aspergillosis
P- Pneumoconiosis: coal, silica.
E- Extrinsic allergic alveolitis
N- Negative, sero-arthropathy
T- TB

Question 4

Lower zone causes of ILD (STAIR)

Answer 4

STAIR

S- Sarcoidosis
T- Toxins
A- Asbestosis
I- Idiopathic
R- Rheumatological

Question 5

Connective tissue/ AI disease causes of ILD

Answer 5

• RA
• SLE
• Systemic sclerosis
• Poliomyelitis

Question 6

Environmental causes of ILD

Answer 6

• Asbestosis
• Silicosis
• Hypersensitivity pneumonitis (Extrinsic allergic alveolitis)
• Pneumoconiosis

Question 7

Infective causes of ILD

Answer 7

Bacterial
- TB
- Aypical pneumonia
- Chlamydia trachomatitis

Fungal
- PCP

Viral
- COVID-19

Question 8

Drugs that cause ILD

Answer 8

Antibiotics
- Nitrofuranotoin
Chemotherapy

Antiarrhythmics
- Amiodarone

DMARDs
- Methotrexate
- Sulfasalazine

Question 9

Hypersensitivity pneumonitis (Extrinsic allergic alveolitis)
- Definition

Answer 9

Inflammation of alveoli and distal bronchioles caused by hypersensitivity to allergen exposure.

Classifications
- Acute: - Symptoms develop 4-6 hours following heavy exposure.
- Subacute
- Chronic: Granuloma formation and obliterative bronchiolitis, Lack of acute episodes.

Question 10

Hypersensitivity pneumonitis examples

Answer 10

Bird fancier’s lung
- Exposure: feathers, bird droppings
- Allergen: avian proteins

Farmer’s lung
- Exposure: Mouldy hay
- Allergen: aspergillus and other bacteria

Question 11

Pathophysiology of Hypersensitivity pneumonitis

Answer 11

Hypersensitivity reactions:

Type 3 hypersensitivity
- Immune complexes giving risk to abnormal inflammatory responses.
- Example: Farmer’s lung (moldy hay).

Type 4 hypersensitivity
- T cell mediated inflammation directed at antigen.

Question 12

Specific investigation findings for hypersensitivity pneumonitis

Answer 12

1. Immunoassay for specific antigens
   - Will show Abs formed against antigens.
2. CT chest
   - Ground-glass shadowing
   - Poorly defined micronodules
   - Chronic features: mosaic attenuation, centrolobular nodules, relative basal sparing.
3. Pulmonary function test
   - Restrictive pattern.

Question 13

Idiopathic pulmonary fibrosis
- Definition

Answer 13

Most common cause of interstitial lung disease, of unknown aetiology.
- Scar tissue formation within the lungs
- Progressive dyspnoea.

Question 14

Idiopathic pulmonary fibrosis
- Risk factors

Answer 14

• Cigarette smoke
• Family history
• Male sex
• Advanced age
• Organic/metal dust exposure
• GORD
• DM
• Certain Infections

Question 15

Genetics of IPF

Answer 15

Subset is familial= Familial pulmonary fibrosis.
- Affects younger age (55-60)
- Autosomal dominance, incomplete penetrance

Question 16

Specific findings for idiopathic pulmonary fibrosis.

Answer 16

Signs
- Expiratory, bacillar crackles. Dry and Velcro in quality.

Bloods
- CRP and ESR may be elevated
- Normal/ mildly elevated anti-nuclear antibodies/ rheumatoid factor.

Imaging
- CXR–> opacities

• High resolution CT: basilar and subpleural reticulation, honeycombing

PFT
- Restrictive pattern

Question 17

Acute exacerbation management of IPF

Answer 17

1. Admit + high dose corticosteroid
   - Prednisolone OD, 4 weeks, then taper off.

Question 18

Ongoing management of IPF

Answer 18

1. Antifibrotic therapy
   - Pirfenidone
   - Nintedanib
2. Lung transplant

Adjuncts
- PPI (GORD patients)= lansoprazole/ omeprazole
- Smoking cessation
- Oxygen
- Pulmonary rehab

Question 19

Pneumoconiosis

Answer 19

Type of interstitial lung disease caused by inhalation of dust.

Types
- Coal workers’
- Asbestosis
- Silicosis

Question 20

Silicosis
- Complications
- Presentation
- Specific findings

Answer 20

Complications
- Lung cancer.
- Progressive massive fibrosis.
- Respiratory failure

Presentation
- Dyspnoea
- Cough
- Fever
- Cyanosis (acute exacerbation)

Specific findings
CXR/ CT:
- Upper lobe
- Nodular lesions
- Egg shell calcification of hilar nodes.

Question 21

Asbestosis
- Complications
- Presentation
- Specific findings

Answer 21

Complications
- Lung cancer
- Mesothelioma
- Pulmonary heart disease
- Pleural fibrosis

Presentation
- Progress dyspnoea
- Chest pain
- Weight loss
- Clubbing

Specific findings
High resolution CT Chest/ CXR, PA and lateral:
- Lower zone interstitial fibrosis
- Pleural thickening/ plaques
- Pleural effusions.

Question 22

Coal workers’ pneumoconiosis
- Complications
- Presentation
- Specific findings

Answer 22

Complications
- Chronic bronchitis
- Progressive massive fibrosis

Presentation
- Progressive dyspnoea
- Chronic bronchitis

Specific findings
- Upper zone fibrotic masses

Question 23

Sarcoidosis

Answer 23

Chronic, multisystem disease of unknown cause characterised by collections of granulomas.

Classifications
- Systemic, pulmonary, cutaneous, ocular, cardiac, neurosarcoidosis.