Interstitial Lung Disease Flashcards
What is interstitial lung disease?
Any disease process affecting lung interstitium
What is pulmonary interstitium made of?
Alveolar lining cells - type 1 & 2
Thin elastin-rich connective tissue with capillary blood vessels
How can early and late stage be differentiated?
early - alveolitis
late - fibrosis
What are the symptoms of ILD?
- breathlessness
- dry cough
Due to hypoxia and cardiac failure
State two causes of ILD
- environmental (minerals, drugs, radiation)
- idiopathic
Describe the three types of ILD
Acute - viral or inhalation of toxic substance
Episodic - comes and goes
Chronic - part of system disease, exposure to agent, idiopathic, sarcoidosis or pneumoconiosis
What type of sensitivity reaction is sarcoidosis? What is the cause?
Type 4 involving granulomas
Unknown aetiology
Which population has a higher incidence of sarcoidosis?
African americans & people of caribbean origin
Where in the body can be affected by sarcoidosis?
- lungs
- lymph nodes
- joints
- liver
- skin (erythema nodosum)
- eyes (uveitis)
What kind of granuloma is sarcoidosis?
Non caseating
Describe the symptoms of acute sarcoidosis
- erythema nodosum
- bilateral hilar lymphadenopathy
- arthritis
- uveitis
- parotitis
- fever
Describe the symptoms of chronic sarcoidosis
- lung infiltrates
- skin infiltrates
- peripheral lymphadenopathy
- hypercalcaemia (abnormal vitamin D metabolism in granulomas)
What investigations should be done on a patient with suspected sarcoidosis? How can it be treated?
- CXR
- CT scan
- tissue biopsy
- pulmonary function test
- blood test
acute - self limiting
chronic - oral steroids if affecting vital organ if unsuccessful immunosuppressive drugs are required
What type of hypersensitivity is extrinsic allergic alveolitis?
type 3 - reaction to antigen lymphocytic alveolitis
Describe the aetiology of EAA
- thermophilic actinomycetes (mould on hay)
- avian antigens
- drugs
- idiopathic
What are the symptoms and treatment of acute EAA?
S - cough, breathlessness, fever, myalgia
T - oxygen, steroid, antigen avoidance
What are the signs and symptoms of chronic EAA?
cough, breathlessness, crackles and fibrosis in upper lobes due to inhalation
Name three investigations that should be done on a patient with suspected chronic EAA
- Pulmonary function tests (low FEV1/FVC)
- CXR
- lung biopsy
What is the diagnosis and treatment of chronic EAA?
D - history, IgE antibodies to guilty antigen
T - remove antigen and oral steroids for breathlessness
Describe the aetiology of idiopathic pulmonary fibrosis
It is unknown but the lungs develop an imbalance in their repair system
Name four secondary causes of IPF
- rheumatoid
- systemic sclerosis
- asbestos
- drugs
What drugs can cause IPF
amiodarone busulphan bleomycin pencillamine nitrofutatoin (for recurrent UTIs) methotrexate
Describe the presentation, examination and investigation findings of IPF
P - progressive breathlessness and dry cough
E - clubbing, bilateral fine inspiratory crackles
I - restrictive defect on PFTS (reduced FEV1/FVC)
What will be found on CXR and CT for patients with IPF?
CXR - bilateral infiltrates
CT - reticulonodular fibrotic shadowing, worse at the lung bases. Honeycombing cystic changes traction bronchiectasis.
