Interstitial Lung Disease Flashcards
What is interstitial lung disease?
A group of disorders characterised by inflammation and fibrosis of the lung parenchyma and typically the lung interstitum. It is caused by recurrent alveolar injury and tends to affect the lower lung lobes
Higher prevalence in older adults
Which demographic is most affected by idiopathic pulmonary fibrosis?
Typically affects males over 60 with a smoking history. It has a higher prevalence in older adults and idiopathic pulmonary fibrosis. There may be acrocyanosis, where there is continual colour changes due to vasospasm.
Higher prevalence in older adults
What are common symptoms of idiopathic pulmonary fibrosis?
- Gradual onset of shortness of breath
- Progressive dyspnoea
- Dry cough
- Fine Velcro crackles
- Nail clubbing
Fine Velcro crackles do not disappear after coughing
What do pulmonary function tests reveal in idiopathic pulmonary fibrosis?
- Restrictive lung capacity
- Decreased functional vital capacity
- Low DLCO
DLCO stands for Diffusing Capacity of the Lung for Carbon Monoxide
What is a key risk factor for idiopathic pulmonary fibrosis?
Cigarette smoking and age between the 5th and 6th decade of life
More common in males
What is the pathophysiology of idiopathic pulmonary fibrosis?
Environmental factors like smoking, chronic aspiration and infections and combined with advancing age results in repetitive cycles of alveolar type 1 epithelial injury which causes oedema and crackles and there is triggering the activation of fibroblasts. This leads to diffuse interstitial fibrosis and causes dilatation of the proximal small airways known as traction dysregulated repair with increased matrix deposition that destroys the lung architecture and the development of pulmonary fibrosis.
What are common environmental factors contributing to idiopathic pulmonary fibrosis?
- Smoking
- Chronic aspiration
- Infections
- Advancing age
These factors cause repetitive cycles of alveolar type 1 epithelial injury
Name drugs that should be avoided in idiopathic pulmonary fibrosis.
- Ambrisentan
- Azathioprine
- Bosentan
- Co-trimoxazole
- Mycophenolate mofetil
- Prednisolone
- Sildenafil
- Warfarin
These medications can exacerbate the condition
What findings are associated with the diagnosis of idiopathic pulmonary fibrosis?
- PFT with restrictive pattern
- Bronchoalveolar lavage showing increased macrophages and neutrophils
- Serum acute phase reactants may show ANA or rheumatoid factor
- ABG will show respiratory alkalosis due to dyspnoea, with high pH, low PCO2 and partial compensation with low HCO3 and low PaO2 due to diffusion defect
ABG stands for Arterial Blood Gas
What does a high resolution CT scan reveal in idiopathic pulmonary fibrosis?
- Ground glass appearance initially
- Honeycomb appearance in the peripheral and lower lobes
- Traction bronchiectasis
Honeycomb lung appearance indicates advanced disease
What is the prognosis for idiopathic pulmonary fibrosis?
3-5 years
Prognosis can vary based on disease progression and management
What are the findings for idiopathic lung fibrosis?
Findings include fine Velcro crackles with clubbing of the fingers, high resolution CT scan of the chest.
What is the management of idiopathic pulmoanry fibrosis?
Management of IPF includes recording PFTs every 3-6 months, and reccomended vaccination wih influenza and pneumococcal due to increased risk. Anti fibrotic medication includes tyrosine kinase inhibitors like pirfenidone and nintedanib which prevents fibroblast activation
-> pirfenidone causes photosensitivity and rash
-> nintedaaniv cauases over abnormalities
Which drugs can induce intrinsic lung disease?
-> Amiodarone which is associated with causing atrial fibrillation and ventiruclar tachycardia
-> Bleomycin used for cancer treatment
What is a pneumonicosis?
lung pathology caused by dust inhalation:
Sarcoidosis: worker in mines
Asbestosis: worker in insulation
Berrylosis: worker in ceramics
Coal-miner’s lung
What are the autoimmune conditions that cause interstitial lung disease?
-> rheumatoid arthritis
-> systemic lupus arthritis
-> goodpasture’s
-> granulomatous erythmatosis
Which extrinsic lung conditions can cause intrinsic lung disease?
Chest wall deformities which reduces chest expansion and inspiration
-> Kyphoscoloiosis
-> Obesity hypoventilation syndrome
Which neuromuscular dysfunction causes intrinsic lung disease?
Guillan-Barre syndrome. myasthenia gravis, ALS, spinal cord injury.
What is the pathophysiology of intrinsic lung disease?
conditions cause lung fibrosis which causes it to shrink via increased elastic recoil, which reduces compliance and reduces lung expansion for inspiration. Fibrosis will cause a diffusion defect that is exacerbated during exercise and leading to hypoxia.
This can result in hypoventilation and causes a V/Q mismatch, with hypoxaemia and hypercapnia that lead to type 2 respiratory failure.
Chronic hypoxaemia can cause type 3 pulmonary artery vasoconstriciton and lead to right ventiruclar overload.
-> presents with JVP, hepatomegaly, pedal oedema and ascites
What are the PFT’s for intrinsic lung disease?
It is characterised by reduced FEV1, FVC, all long volumes and capacities and severity is determined by the total long capacity-> the lower the total lung capacity, the worse the restriction.
What does upper lobe fibrosis indicate?
silicosis
What does lower lobe fibrosis indicate?
asbestosis and idiopathic pulmonary fibrosis
What does pleural fibrosis indicate?
asbestosis
What does lymphadenoapthy idnicaate?
berrylosis
Bilateral lymphadenopathy indicates sarcoidosis
What does honeycomb pattern on lungs indicate?
idiopathic pulmonary fibrosis
What does normal DLCO indicate?
extrnsinc lung disease
What des reduced DLCO indicate?
Reduced DLCO indicates intrinsic lung disease so assess for drug related or occupation related exposures. No exposures means that antibiotic testing should be assessed with ANA, RF, ANCA or anti-GBM
What does a low CD4:CD8 ratio in bronchial fluid indicate?
hypersensitivity pneumonitis
What does a high CD4:CD8 ratio indicate?
sarcoidosis
What is sarcoidosis?
A chronic immune-related inflammatory condition caused by a non-caseating granuloma. It typically affects the lungs and causes mediastinal lymphadenopathy, pulmonary fibrosis and pulmonary nodules but has multisystem effects. It tyupocally affects black women in their 20s40s.
Typically affects the lungs and has multisystem effects
What is the aetiology of sarcoidosis?
Aetiology is linked to occupational/environmental exposures to beryllium and dust or mutation of chromosome 6 MHC gene. It is more common in black populations and women.
What is the pathophysiology of idiopathic sarcoidosis?
interaction with unknown antigen induces CD4+ T helper cells tor ecruit macrophages to form the non-caesatng granuloma which contain epitheioid histiocytes and giant cells. The macrophages synthesise 1-a-hydroxylase which activates vitamin D, increasing calcium absorption and causing hypercalcaemia, increasing risk of kidney stones.
*It causes hilar lymphadenoapthy and these hilar lymph nodes drink into the mediastinal lymph nodes and cause mediastinal lymphadenoapthy.
- There may also be hypergammaglobulinaemia and raised ACE due to elevated activity of macrophages. High T cell activity causes B cell stimulation, leading to raised serum immunoglobulins and immune complexes. There is a reduction in delayed-type hypersensitivity reactions
How is the liver affected in sarcoidosis?
cirrhosis and choelstasis and most common cause of non infectious hepatitis
How is the skin affected in sarcoidosis?
erythema nodosum (tender red nodules on the shins due to subcutaneous fat inflammation which has a good prognosis and is also associated with ) and lupus pernio (raised purple lesions of skin nose and cheeks that has a bad prognosis)
How is the art affected in sarcoidosi
causing bundle branch block and heart block and cardiomyopathies if depositied into myocardium and may cause restrictive cardiomyoapthy
What are the stages of sarcoidosis based on radiological findings?
- Stage 0: Normal
- Stage 1: Hilar lymphadenopathy
- Stage 2: Hilar lymphadenopathy and parenchyma infiltrate
- Stage 3: Parenchyma infiltrate
- Stage 4: Fibrosis
Staging helps in assessing disease progression
What are common clinical presentations of sarcoidosis?
- Dry cough
- Dyspnoea
- Blurry vision
- Palpable lymph nodes
- Painful swollen joints
- Proximal myopathy
In more severe cases, heart block and sudden death may occur, therefore it is reccomended that an implantable ICD
Other symptoms may include fever and psychiatric overtone
What is Lofgren syndrome?
A mild acute form of sarcoidosis characterised by fever, erythema nodosum, bilateral hilar lymphadenopathy, and polyarthritis. On biopsy, there are naked granuloma with little surrounding lymphocytic inflammation. Treatment is typically supportive with NSAIDs or corticosteroids because the condition generally self-resolves.
Typically presents acutely in younger patients
What is erythema nodosum?
Erythema nodosum is painful bright red subcutaneous bilateral nodules on the anterior shins, along with a fever.
What are the clinical signs of sarcoidosis?
tachypnoea, Inspiratory crackles, friction rub due to pleurisy or pericarditis. Triphasic with pericarditis and biphasic with pleurisy. Opthalmolgocal signs include corneal opacitieisand gluaucoma.
What is the cardiac symptoms of sarcoidosi?
Cardiac symptoms may include palpitations, syncope and dizziness, shown through echocardiogram that shows restrictive cardiomyoapthy. Treatment is with systemic steroids, prednisolone or immunosuppressants.
What are the systemic symptoms of sarcoidosis?
Systemic symptoms include fever, sweats, loss of appetite and weight loss.
What is the relationship between sarcoidosis and hypercalcaemia?
Macrophages synthesise 1-alpha-hydroxylase, increasing calcium absorption
This can lead to kidney stones
What are the common complications of sarcoidosis?
- Interstitial pulmonary fibrosis
- Cor pulmonale
- Increased risk of aspergillosis in lung cavities
Cor pulmonale is caused by pulmonary artery vasoconstriction
What is the diagnostic features for sarcoidosis?
Serum ACE is raised and can be used to monitor disease progression
Hypercalcaemia
Bronchoalveolar lavage showing increased CD4:CD8+ ratio
Soluble iL-2 receptors
CXR showing bilateral hilar lymphadenopathy
Bronchoscopy showing an increased CD4:CD8 ratio
What is the gold standard for testing sarcoidosis?
Histology where biopsy of granuloma area showing non-caesating granuloma with epithelioid cells
What is the treatment for sarcoidosis?
Initial treatment with high dose 40mg Oral steroids such as prednisolonefor 6-24 months with bisphosphonates to prevent osteoporosis. Can later reduce dose to 5-20mg for maintenance. If this fails, IgG dose intravenous methylprednisolone is useful, especially for neurosarcoidosis.
Immunosuppressants like methotrexate and azathriopine
What are the side effects of methotrexate?
-> methotrexate should be avoided with hepatic or renal failure and can cause GI upset, stomatitis, pneumonia and is teratogenic
What are the side effects of Azathriopine?
myelosuppression and fever
What are the side effects of cyclophosphamide?
cyclophosphamide should be used for neurosarcoidosis unresponsive to steroids
Pulmonary transplantation for severe disease
What is the management of sarcoidosis?
-> 60% of patients have spontaneous resolving of symptoms
->Pulmonary fibrosis and dhypertension can mean transplantation is required
->Death is usually due to heart involvement causing arrythmias and CNS involvement
->Hypercalcaemia should be managed by limiting dietary calcium intake and provide steroids and increasing fluid intake
->Skin lesions can be treated with topical steroids, otherwise lupus pernio should be treated with systemic steroids.
-> Treatment of eye inflammation is with local steroids
->Renal involvement is treated with steroids and hyodrxychloroquine
What are the types of asbestos fibres?
- Serpentine: curly and flexible, associated with interstitial pulmonary fibrosis and lung cancer
- Amphibole: straight and rigid, associated with interstitial pulmonary fibrosis, lung cancer, and mesothelioma
Different types of asbestos have different health impacts
What is the pathophysiology of asbestosis?
Inhalation of asbestos fibres causes interaction with epithelial cells and macrophages, leading to interstitial fibrosis. Deposition of fibres typically occurs in the lower lobes, related to intensity and duration of asbestos exposure as a result of radial oxygen species. The severity and rate of progression is influenced by cigarette smoking. It begins centrally and moves peripherally. deposition of fibres typically occurs in the lower lobes, related to intensity and duration of asbestos exposure as a result of radial oxygen species. The severity and rate of progression is influenced by cigarette smoking. It begins centrally and moves peripherally.
Affects the lower lobes
What is the key feature of asbestosis?
Asbestosis can cause lower lobe bronchi dysplasia and lead to bronchoalveolar carcinoma , or pleural dysplasia and mesothelioma.
What imaging findings are consistent with interstitial lung disease?
- Reticulonodular opacities on CXR due to visceral pleura thickening and leads to a restrictive lung disease, with reduced chest expansion and clubbing. The severity is dependent on exposure levels.
- Honeycomb pattern on high resolution CT
Imaging is critical for diagnosis
What is the significance of DLCO in pulmonary function tests?
Normal DLCO indicates extrinsic lung disease; reduced DLCO indicates intrinsic lung disease
Helps assess for drug-related or occupational exposures
What are the systemic treatments for sarcoidosis?
- High-dose oral steroids (prednisolone)
- Immunosuppressants (methotrexate, azathioprine)
Treatment may depend on the severity of symptoms
What is the primary cause of asbestosis?
Inhalation of asbestos fibres
Asbestosis is characterized by diffuse interstitial pulmonary fibrosis due to asbestos exposure.
Where does the deposition of asbestos fibres typically occur in asbestosis?
Lower lobes. They can become coated with iron and haem to form a ferruginous bodies, that can better be visualised with Prussian blue stain they appear golden brown
The severity and progression of asbestosis are related to the intensity and duration of exposure.
What inflammatory mediators are involved in the pathophysiology of asbestosis?
- TNF
- Oxygen derived free radicals
These mediators induce interstitial fibrosis.
What type of lung disease is caused by asbestosis?
Restrictive lung disease
It is characterized by reduced chest expansion and clubbing.
How does cigarette smoking influence asbestosis?
It influences the severity and rate of progression
Cigarette smoking exacerbates the effects of asbestos exposure.
What radiological findings are associated with asbestosis?
- Small linear opacities
- Ground glass opacities
- Dumbbell shaped ferruginous bodies
These findings are typically visible on a Chest X-ray.
What is the role of high resolution CT in diagnosing asbestosis?
More sensitive for identification of honeycomb lung
Both HRCT and CXR are not very sensitive for detecting asbestosis.
What is the treatment of asbestosis?
There may be signs of cor pulmonale such as pedal oedema as a result of pulmonary vascular remodelling. It has a restrictive lung disease pattern with reduced Kyle volumeDLCO is reduced with maintained FEV1 and FVC. ABG may show hypoxia and respiratory alkalosis. Treatment is with corticosteroids and immunosuppressive drugs can be used as an alternative or oxygen therapy for patients with hypoxaemia.
What complications can arise from asbestos exposure?
- Benign pleural plaques
- Primary bronchogenic carcinoma
- Malignant mesothelioma
These conditions are linked to occupational asbestos exposure.
What is the latency period for asbestos-related diseases?
20-40 years
This latency period follows exposure to asbestos.
What is the most common lesion associated with asbestosis?
Benign pleural plaques
-> MULTIPLE white/yellow calcified plaques on the parietal pleura or diaphragm dome and increase the risk of pleural effusion, but no effect on risk for mesothelioma. This can be better viewed radiologically, showing ivory white supradiaphragmatic and pleural plaques. It develops 20-30 years after exposure and high resolution CT scan are more sensitive than CXR for detecting pleural plaques
These plaques are typically multiple white/yellow calcified plaques on the parietal pleura.
What is diffuse pleural thickening?
Diffuse pleural thickening where fibrosis of the visceral pleural may occur, with ill-defined margins and follows reccurrent asbestos pleurisy. CXR may show pleural opacity over at least a quarter of the chest wall and presents commonly with symptoms like Exertional breathlessness and chest pain.
What is rounded atelectasis?
Rounded atelctasis/Blesovsky syndrome develops as contracting visceral pleural fibrosis, creating a mass 2.5-5cm in diameter, typically diagnostic with CT. It is typically asymptomatic and stable and slowly progressive, with no specific treatment/
What is malignant mesothelioma?
Malignant mesothelioma is a malignant tumour that invades the subpleural lung tissue from a latency period following asbestos exposure 25-40 years. This can lead to haemorrhagic pleural effusion and pleural thickening. It arises form the serosa cells of the pleura and is unrelated to dose-exposure. There will be psammoma bodies and calretinin positive. Non-asbestos related causes include Eriodonite, found in rocks in cappadocia.
What is Caplan syndrome?
Rheumatoid arthritis with rheumatoid nodules in longs nand coal worker pneumonicosis
Wbat is a poor prognosis for mesothelioma?
Poor prognosis for mesotheiolima is transdiaphramatic muscle invasion, male gender, sarcamatoid histology no involvement of mediastinal lymph nodes.
What are the three historical subtypes of malignant mesothelioma?
- Epitheliod: better prognosis
- Sarcomatoid: poor prognosis
- Mixed
Each subtype has different prognostic implications.
What is the pathophysiology of idiopathic of malignant mesothelioma?
Nodules form and originate from the parietal pleura, which typically spreads to the visceral pleura and invades into adjacent structures such as the chest wall diaphragm and mediastinum. Lymph node involvement is typically the bronchopulmonary/hilar lymph nodes and nodal spread is direct and local but is typically uncommon.
What are the common symptoms of malignant mesothelioma?
- Dull diffuse chest pain
- Shortness of breath
- Haemoptysis
- Unintentional weight loss
- Cough
- Fatigue
Symptoms often indicate advanced disease.
What is a complication with pneumothorax?
Pneumothorax can occur due to damage of the bronchial tree in pleural space.
Complications include SVC obstruction, cardiac tamponade and spinal cord compression and distant metastases is common.
There is a poor prognosis with survival of 1 year and average age of diagnosis is 72 and the disease typically appears around 50 to 60s at a later stage and treatment dependents on disease stage
What are the risk factors for mesothelioma?
Risk factors for mesothelioma include asbestos exposure with a latency period of 20 to 440 years, ionising radiation or genetic predisposition with genetic mutation in the BRCA1 gene.Professions with high asbestos exposure include mining, shipbuilding, ceramics, insulation and road repair.
What are the diagnostic findings for mesothelioma?
*Sputum sample with bronchoalveolar lavage showing ferruginous bodies
*pleural fluid analysis showing straw. Coloured or bloody effusion
*High resolution CT is best and shows opacities in lower lung fields
CXR will show pleural effusion with encasement of the lung
*Radiology showing asbestosis in the lungs
*Pleura thickening or calcification in lower long fields and white plaques
*Pleural fluid analysis showing exudative straw-coloured or serous or bloody exudate
*Pulmonary function test showing restrictive pattern
*Reduced DLCO
What is the typical age of diagnosis for malignant mesothelioma?
72 years
The disease typically appears in individuals around their 50s to 60s.
What is the prognosis for malignant mesothelioma?
Average survival is 9-12 months post diagnosis
Prognosis is poor, especially with advanced disease.
What is the treatment of mesothelioma?
Systemic therapy with chemotherapy with Pemetrexel and Cisplatin
-> this is in combination with folic acid and b12 supplementation
Immunotherapy with PD-1 inhibitor and CTLA-4 inhibitor
Radiotherapy, adjuvant used post-operative LH or palliative for symptom management for chest wall diaphragm pain or dyspnoea
Pleural intervention with pleurodesis
Symptom management with pain control, nutrition and psychosocial care
What is the management of asbestos exposure?
Supportive care
Talc pleurodesis to reduce the occurrence of pleural effusion
Mesotheliom: surgery, radiation, chemotherap with cisplatin and pemetrexell
-> pecletexel works by inhibiting DNA synthesis proteins like thymidylate synthase
-> cisplatin works by inducting DNA alkylation
Median survival with mesothelioma is 9-12 months post diagnosis, with involvement of the contralteral lung, SVCO syndrome and cardiac tamponade.
What is the role of talc pleurodesis in managing asbestos exposure?
Reduces the occurrence of pleural effusion
It is a supportive care measure.
What is the main treatment for malignant mesothelioma?
- Surgery
- Radiation
- Chemotherapy with cisplatin and pemetrexed
Treatment options vary based on disease stage.
What are the typical findings in a CXR for silicosis?
- Ground glass appearance
- Nodular opacities
- Egg shell calcifications in hilar lymph nodes
These findings are indicative of silicosis, especially with chronic exposure.
What is coal worker’s pneumonicosis?
Coal worker’s Pneumonicosis involves inhalation of coal dust from either coal mines or tobacco smoke that can result in te formation of anthracotic pigments which can become consumed by alveolar macrophages and become dust cells. causing inflammation of the intersistial tissue of the lung and the hilar lymph nodes. Patients with coal wor’ers pneumonicosis are typically asymptomatic.
What is simple pneumonicosis?
fibrotic opacity is less than 1cm, typically affecting the upper lobes and upper portion of the lower lobes and progression is dependent on the amount of coal dust consumed. It typically causes obstructive lung disease and results in emphysema.
What is complex pneumonicosis?
fibrotic opacity is over 1-2cm and occurs at the lung apex, with no correlation to exposure. It causes a restrictive lung disease pattern with risk of cor pulmonale, carcinoma and there is no treatment available. It forms part of Caplan syndrome, where there is pneumonicosis with pulmonary nodules and rheumatoid arthritis.
What are the features of Caplan syndrome?
In Caplan syndrome, there is a necrobiosis rheumatoid nodule containing a central necrotic core of black coal dust and necrotic tissue, with an active zone of inflammation in the lungs or concentric rings of coal dust. There will be rapid development of multiple nodules which obstruct airflow but majority of patients are asymptomatic but may experinece dry cough, pleuritic chest pain, SOB and fatigue.
What are the diagnostic markers for Caplan syndrome?
Serum markers ifor diagnosis include ANAA (antinuclear antibody) rheumatoid factor and ANCA (antineutrophil cyptoplasmic antibodies). Management is to reduce exposure, administer corticosteroids to slow progression and provide supportive care.
What is the most common occupational disease?
Silicosis is caused by inhalation of silica quarts from dust, which are small enough to bypass mucociliary apparatus activating alveolar macrophages, causing cytokine release for surfactant cells to increase production, resulting in build-up of protein Aeolus debris in alveoli called silicoproteinosis and leading to irreversible lung fibrosis in the upper lungs. Within the macrophages, the silica dust is resistant to degradation and causes the production of reactive oxygen species and cellular destruction and contents are released. There is a concentrically arranged zone with a peripheral poorly organised zone.
What are the types of silicosis?
Simple: small lung nodules due to chronic exposure within 10 to 30 years and have an asymptomatic presentation or dry cough/dyspnoea.
Complicated: large lung nodules which can coalesce to cause a progressive large fibrosis
Silicoproteinosis: rare, caused by overwhelming exposure within 5 years of exposure to silica dust causes eosinophilic materials to fill the alveoli, causing alveolitis and may be mistakenly identified as pulmonary oedema.
What is the presentation of silicosis?
Patients with silicosis present with cough, dyspnoea and are at risk of progressive massive fibrosis, cor pulmonale due to pulmonary artery vasculature remodelling, Caplan syndrome, TB and lung cancer.
What are the features of silicosis?
Patients with silicosis present with cough, dyspnoea and are at risk of progressive massive fibrosis, cor pulmonale due to pulmonary artery vasculature remodelling, Caplan syndrome, TB and lung cancer.
CXR will show multiple bilateral nodules in the upper and middle lobes and enlargement of hilar and mediastinal lymph nodes.
What is the treatment for silicosis?
treatment is prevention of fibrosis through exposure avoidance and whole lung lavage to slow progression or anti-fibrotic therapy. Steroids may alleviate inflammation with acute silicosis and lung transplantation is a last resort. Supportive treatment may be offered with supplemental oxygen.
What is Berrylosis?
Berylliosis is a granulomatous lung disease associated with inhalation of beryllium with risk from working in aerospace industry, dentistry, metal alloys.
What type of hypersensitivity reaction is involved in berylliosis?
Type 4 hypersensitivity reaction driven by sensitised T cells that results in non-Necrotising granuloma formation of macrophages and CD4+ T cells in the upper lobes that causes chronic interstitial pneumonitis -> fibrosis and presents clinically with cough and SOB, fever, night sweats and fatigue. There is a latency period from 3 months to 30 years.
This reaction results in non-necrotizing granuloma formation.
What is the diagnostic features of Berrylosis?
bronchoalveolar lavage, beryllium lymphocyte proliferation test and granulomatous inflammation on lung biopsy.
*CXR and high resolution CT will show nodules along septal lines, ground glass opacities and parenchyma nodules
*Beryllium lymphocyte proliferation test: acquiring peripheral blood or fluid from bronchial alveolar lavage and culturing lymphocytes with beryllium sulphate, where elevated count is abnormal.
*Bronchoscopy and bronchoalveolar lavage is performed to obtain cell count
What are the complications of Berrylosis?
Acute pneumonitis
Pulmoanry fibrosis
Chronic granulomatous disease
What is the treatment of Berrylosis?
Management is with steroids, methotrexate immunosuppressant as an lternative with low dose with folic acid. Prognosis is good in the absence of chronic exposure, but has a highly variable clinical course and can impair lung fucntion due to nodule formation
What clinical features are associated with hypersensitivity pneumonitis?
- Breathlessness
- Dry cough
- Systemic symptoms (fever, chills, arthralgia)
Symptoms may resolve within 1-3 days after exposure.
What is the cause of Farmer’s lung?
Exposure to mouldy hay
This condition is a type of hypersensitivity pneumonitis.
What is Caplan syndrome?
Rheumatoid arthritis with rheumatoid nodules in lungs and coal worker pneumoconiosis
It features necrobiosis and rapid development of multiple nodules.
What is the most common occupational disease in the world?
Silicosis
It results from inhalation of silica dust.
What is hypersensitivity pneumonitis?
Hypersensitivity pneumonitiis is an interstitial lung disease characterised by immunological reaction of the lung parenchyma in response to repetitive inhalation of a sensitised allergen that causes immune complex-mediated 4 hypersensitivity and mediated by IgA and IgG after initial sensitisation.
What is acute hypersensitivity pneumonitis?
Acute hypersensitivity pneumonitis following a short period of exposure (4-6hrs) to antigen which is reversible and affects the airways and bronchi, due to the inhalational nature with poorly-formed non-caesating granuloma and inflammatory cell infiltrates. Clinical features of hypersensitivity pneumonitiis includes breathlessness, dry cough and systemic psymptoms with fever, chills, arthralgia, myalgia and headache. There is crackles and squeaks on auscultation, and symptoms may resolve in 1-3 days. There are diffuse small nodules with ground glass change and increased lucency due to air trapping from bronchiolar involvement.
What is chronic hypersensitivity pneumonitis?
Chronic hypersensitivity pneumonitis following a chronic exposure to antigen and is less reversible. There is fibrosis and and absence of granulomata involvement.
Clinical features include progressive exertional breathlessness, finger clubbing, dyspnoea, productive cough, systemic symptoms like weight loss, with crackles and squeaks on auscultation. There is typically upper and mid-zone reticulation with centrilobular nodules.and there is a restrictive pattern with PFTs
What is the main cause of Farmer’s lung?
Exposure to mouldy hay
Farmer’s lung is a type of hypersensitivity pneumonitis resulting from inhalation of organic antigens found in mouldy hay.
What type of hypersensitivity reaction is associated with Farmer’s lung after continued exposure?
Delayed IV hypersensitivity
This reaction activates CD8+ cytotoxic cells in response to chronic antigen exposure.
What are the clinical features of Farmer’s lung?
Progressive exertional breathlessness, finger clubbing, dyspnoea, productive cough, systemic symptoms like weight loss, crackles and squeaks on auscultation
These symptoms indicate lung involvement and systemic effects due to chronic inflammation.
What is typically observed in imaging for Farmer’s lung?
Upper and mid-zone reticulation with centrilobular nodules
This imaging pattern indicates interstitial lung disease associated with chronic exposure.
What are the diagnostic features of hypersensitivity pneumonitis?
It is associated with neutrophilia and diagnosis with onset of symptoms 4-8 hours after exposure, presence of weight loss and finding of crackles on examination.
Management is based on antigen avoidance, but if necessary, corticosteroids are required
What pattern is shown in pulmonary function tests (PFTs) for Farmer’s lung?
Restrictive pattern
This pattern reflects decreased lung volume and capacity due to fibrosis.
What laboratory findings are associated with Farmer’s lung?
Elevated ESR, CRP, and IgG positive for a specific antigen
These findings indicate inflammation and an immune response to the inhaled antigen.
What is the time frame for symptom onset after exposure in Farmer’s lung?
4-8 hours
This delayed response is characteristic of hypersensitivity pneumonitis.
What is the management strategy for Farmer’s lung?
Antigen avoidance, corticosteroids if necessary
Avoiding exposure to the causative antigen is crucial, while corticosteroids can help reduce inflammation.
What is the condition caused by exposure to mould on barley?
Malt worker’s lung
This condition is similar to Farmer’s lung but is specific to workers handling barley.
What is Bird fancier’s lung associated with?
Pet birds, bird droppings
This condition results from inhaling organic dust and proteins from birds.
What condition is associated with chemicals like paints and resins?
Chemical pneumonitis
This condition arises from exposure to harmful chemicals, leading to lung inflammation.
What is Miller’s lung associated with?
Grain exposure
Similar to Farmer’s lung, this condition is related to inhaling organic dust from grain.
