Intersitial Lung Disease Flashcards
what is sarcoidosis
non-caseating systemic granulomatous disease of unknown cause
type 4 hypersensitivity
epidemiology
commonest in northern europe
usual onset aged 20-40
affects afrocarribeans more commonly and severely
less common in smokers
how can sarcoidosis be classified
acute or chronic
symptoms of acute sarcoidosis
erythema nodosum bolateral hilar lymphadenopathy arthritis uveitis fever
symptoms of chronic sarcoidosis
lung infiltrates (alveolitis) skin infiltrations peripheral lymphadenopathy hypercalcaemia other organs- splenomegaly, renal, hepatitis, neurological, myocardial
differntials
lymphoma, TB, carcinoma, fungal infection
pulmonary symptoms/signs of sarcoid
abnormal CXR, bilareral hilar lymphadenopathy, fibrosis, infiltrates, dry cough, progressive dysponea, reduced excercise tolerance, chest pain
non pulmonary signs/symptoms of sarcoidosis
lymphadenopathy, hepatomegaly, splenomegaly, uveitis, conjunctivitis, glaucoma, bells palsy, neuropathy, meningitis, SOL, erythema nodosum, lupus pernio, cardiomyopathy, arrythmia, hypercalcaemia, renal stones, pituitary dysfunction
what is the diagnostic test of sarcoidosis
tissue biopsy showing non caseating granulomas
result of pulmonary function tests in sarcoidosis
restrictive picture
what blood test abnormalities may be present in sarcoidosis
angiotensin converting enzyme levels increased (not diagnositic, but act as disease activity marker)
raised calcium
raised inflammatory markers
treatment of sarcoidosis
acute - self limiting, no treatment usually
chronic - oral steroids (40mg prednisolone OD 4-6 weeks, reduce dose over 1 year), immunosuppression (azathioprine, methotrexate, anti-TNF)
prognosis of sarcoidosis
often relapses - monitor chest x ray and pulmonary function for several years after
what are the indications for steroids in sarcoidosis
uveitis
parenchymal lung disease
hypercalcaemia
neuro/cardiac disease
causes of bilateral hilar lymphadenopathy
TB sarcoidosis mycoplasma organic dust diseases eg silivosis, berylliosis EAA histocytosis
what is extrinsic allergic alveolitis
type II hypersensitivity reaction to antigen
‘hypersensitivity pneumonitis’
can be acute or chronic
causes of EAA
thermophilic actinomycetes (farmers lung, malt workers, mushroom workers)
avian antigens (bird fanciers lung)
drugs (gold, bleomycin, sulphasalazine)
sugar workers lung
clinical features of acute EAA
cough, breathless, myalgia, classically symptoms occur several hours after exposure
signs of acute EAA
pyrexia (not always), crackles but NO WHEEZE, hypoxia
features of chronic EAA
breathless, weight loss, exertional dyspnoea, type 1 resp failure, cor pulmonale, may get clubbing
chest x ray in acute EAA
pulmonary infiltrates
chest x ray in chronic EAA
fibrosis usually UPPER ZONES
pulmonary function test results in EAA
restrictive picture (low FEV1 and FVC, high or normal ratio) low gas transfer TLCO
treatment of acute EAA
oxygen, steroid, antigen avoidance
diagnosis of EAA
history of antigen exposure
positive serum precipitins (IgG antibodies to the guilty antigen)
can lung biopsy if in doubt
treatment of chronic EAA
remove antigen exposure
oral steroids if breathless or low TCLO
what is idiopathic pulmonary fibrosis
MOST common interstitial lung disease
unknown cause
progressive fibrosis
pathology of IPF
‘interstitial pneumonia’- cell infiltrate and inflammation
results in fibrosis
not an inflammatory disease ie. no hypersensitivity reaction
signs/symptoms of IPL
several years - breathless, dry cough, malaise, weight loss, arthralgia
cyanosis, clubbing, fine end expiratory crepitations
complications of IPL
respiratory failure
increased risk of lung cancer
Give other cause of pulmonary fibrosis
rheumatoid, SLE, systemic sclerosis, asbestos, medications
name medications that can cause pulmonary fibrosis
amioderone, busulphan, bleomycin, nitrifuantoin, methotrexate
CT scan findings in IPF
reticulonodular shadowing, worse at bases, broncietesis, honey combing cystic changes
CT scan diagnostic
can do lung biopsy if not
treatment of IPF
steroids and immunosuppresion do not change disease course
typically supportive - oxygen,
new antifibrotic drugs - pirfenidone and nintedanib (expensive and many side effects)
lung transplant if young
prognosis of IPF
median survival 4 years from diagnosis
