interstitial lung disease Flashcards
what is ILD?
an umbrella term, describing a number of conditions that affect the lung parenchyma in a diffuse manner
characterized by chronic inflammation and/or progressive interstitial fibrosis
what illnesses are included under ILD?
- usual interstitial pneumonia (UIP)
- non specific interstitial pneumonia (NSIP)
- extrinsic allergic alveolitis
- sarcoidosis
- many others
what is idiopathic pulmonary fibrosis?
a type of idiopathic interstitial pneumonia
commonest type of ILD
what are the classical findings of UIP?
- clubbing
- reduced chest expansion
- fine inspiratory crepitations in basal/axillary area
- may be features of pulmonary hypertension
what is extrinsic allergic alveolitis?
hypersensitivity pneumonitis
= inhalation of organic antigen to which the individual has been sensitised
what is the acute and chronic presentation of extrinsic allergic alveolitis?
ACUTE = short period, from exposure, 4-8hrs. usually reversible. spontaneously settle 1-3 days. can recur. Get Fever, rigors, myalgia, dry cough, dyspnoea, fine bibasal crackles.
CHRONIC = chronic exposure (months-years). less reversible. Get Finger clubbing (50%), increasing dyspnoea, ↓weight, exertional dyspnoea, type I respiratory failure, cor pulmonale.
what is sarcoidosis?
a multi system inflammatory condition of unknown cause
get non caseating granulomas
immunological response
commonly involves respiratory system but can affect nearly all organs
50% get spontaneous remission, others get progressive disease.
what investigations are done for sarcoidosis?
- PFTs: fibrosis
- CXR: 4 stages
- bloods: renal function, ACE, calcium
- urinary calcium
- cardiac involvement: ECG, ECHO, cardiac MRI, 24 tape
- CT/MRI head: headaches suggests neurological sarcoidosis
what are the treatment principles for ILD?
depends on underlying pathology
- remove occupational exposure
- drug associated = avoid
- stop smoking
- transplantation
- treat infections
- oxygen
- MDT
- palliative care
What can cause ILD?
known causes e.g
- Occupational/environmental, eg asbestosis, silicosis
- Drugs e.g amiodarone
- Hypersensitivity reactions
- Infections eg tb, fungi, viral.
- GORD
systemic disorders can cause e.g
- sarcoidosis
- RA
- sle, systemic sclerosis, mixed connective tissue disease
- Ulcerative colitis, autoimmune thyroid disease.
can also be idiopathic e.g
- idiopathic pulmonary fibrosis
what tests are done to diagnose an acute presentation of extrinsic allergic alveolitis and how is it treated?
1) Blood: fbc (neutrophilia); ↑esr, ABGs, serum antibodies (may indicate exposure/previous sensitization rather than disease).
2) CXR: upper-zone mottling/consolidation
3) Lung function tests: Reversible restrictive defect; reduced gas transfer during acute attacks.
treatment
- Remove allergen
- give O2
- po prednisolone
what tests are done to diagnose a chronic presentation of extrinsic allergic alveolitis and how is it treated?
1) Blood tests: serum antibodies.
2) CXR: upper-zone fibrosis; honeycomb lung.
3) CT chest: nodules, ground glass appearance, extensive fibrosis.
4) Lung function tests: restrictive defect.
treatment
- Allergen avoidance
- Long-term steroids often achieve cxr and physiological improvement.
what are the symptoms and signs of idiopathic pulmonary fibrosis (a type of idiopathic interstitial pneumonia) ?
symptoms -
- Dry cough
- exertional dyspnoea
- malaise
- ↓weight
- arthralgia
signs -
- Cyanosis
- finger clubbing
- fine end-inspiratory crepitations.
what are the complications of idiopathic interstitial pneumonia?
- lung cancer
- resp failure
what investigations are done for ILDs?
- High resolution chest CT is diagnostic
- pulse oximetry
- ABGs
- lung biopsy (to rule out malignancy in young pt with atypical presrntation)
- six minute walk test with pulse oximetry
- echo for cor pulmonale
- serum ACE (can go up in sarcoidosis)
- immunological screen
