Interstitial Lung Disease Flashcards
What is interstitial lung disease?
Any diesase affecting the lung interstitium - the latter parts of the bronchial tree such as terminal bronchi and alveoli
Interstitial lung disease will _______ gas transfer in the lungs
Impair
Interstitial lung disease is a form of _________ lung disease
Restrictive
What is another name for interstitial lung disease?
Diffuse parenchymal lung disease (DPLD)
What are the three types of interstitial lung disease?
- Acute
- Episodic
- Chronic
What may be the causes for chronic interstitial lung disease?
- Systemic disease
- Log term allergen/inflammatory agent exposure
- Idiopathic
What is sarcoidosis?
A condition caused by a hypersensitivity type IV reaction
It is a granuomatous disease involving non-caseating granuloma
Which interstitial lung condition is less common in smokers?
Sarcoidosis
What are the two types of sarcoidosis?
- Acute
- Chronic
Acute sarcoidosis may have signs and symptoms including what?
- Erythema nodosum - inflammation of fat cells under the skin giving a red blotchy appearance
- Bilateral hilar lymphadenopathy - enlargement of lymph nodes arround the hila
- Arthritis
- Fever
Chronic sarcoidosis may have signs and symptoms inlcuding?
- Lung infiltrates - alveolitis
- Skin infiltrates - oedema
- Peripheral lymphadenopathy
- Hypercalcaemia - high calcium level in blood serum
How can sarcoidosis be diagnosed?
- CXR
- CT scans - can show peripheral nodular infiltrate
- Tissue biopsies confirm presence pf non-caseating granulomatous tissue
- Pulmonary function testing will show a restrictive pattern since there are lung infiltrates
- Blood tests can show raised calcium and inflammatory cell levels
Differential diagnosis for sarcoidosis may include what?
- Tb
- Lymphoma
- Carcinoma
- Fungal infection
- Hypersensitivity pneumonitis
How is sarcoidosis treated?
Usually acute sarcoidosis does not need treated by if it affects a major organ steroids can be used
Oral steroids and immunosuppression can be used to treat chronic chronic sarcoidosis
Which types of immunosuppression drugs will be used to treat chronic sarcoidosis?
- if acute self limiting oral steriod if chronic
methotrexate, azathioprine Second line option
* Anti-TNF therapy
What is extrinsic allergic alveolitis also known as?
Hypersensitivity pneumonitis
What is extrinsic allergic alveolitis caused by?
Type III hypersensitivity reaction
This causes deposition of immune complexes around the body
Which conditions can cause extrinsic allergic alveolitis?
- Farmer’s lung
- Malt worker’s lung
- Bird fancier’s lung
Conditions that involve inhalation of a foreign pathogen
What are the three types of extrinsic allergic alveolitis?
- Acute
- Chronic
- Episodic
What symptoms will acute extrinsic allergic alveolitis involve?
- Cough
- Breathlessness
- Fever
- Myalgia
Can come on hours after exposure
What signs are there for acute extrinsic allergic alveolitis?
- Pyrexia
- Crackles
- Hypoxia
- Widespread pulmonary infiltrates on CXR
Describe chronic extrinsic allergic alveolitis
There is a low dose of allergen exposed over time leading to worseing breathlessness and cough
Lung crackles is the main sign and pulmonary fibrosis is common in the upper zones
What is the treatent of chronic extrinsic allergic alveolitis?
- Removal of antigen
- Oral steroids
How is chronic extrinsic allergic alveolitis diagnosed?
- History
- Precipitins (IgG antibodies to putative antigen)
- Lung biopsy
