• Clinical features:
o Progressive exertional dyspnoea
o Dry (non-productive) cough
o Bilateral fine "velcro" crackles
o Clubbing (common)
• Imaging:
o HRCT: subpleural, basal predominance
o Honeycombing, traction bronchiectasis, reticular opacities
• Prognosis: poor; median survival ~3–5 years
• Management:
o Antifibrotic agents: pirfenidone, nintedanib
o Oxygen therapy, pulmonary rehab
o Lung transplantation in selected cases
• Histology: uniform interstitial inflammation and fibrosis (no honeycombing early)
• More common in connective tissue diseases (e.g., scleroderma, dermatomyositis)
• Prognosis: better than IPF/UIP
• Management:
o Steroids ± immunosuppressants (e.g., azathioprine)
• Causes:
o Bird fancier’s lung (avian proteins)
o Farmer’s lung (mouldy hay)
o Mushroom workers, hot tub lung
• Clinical forms:
o Acute: flu-like symptoms, cough, dyspnoea, fever within hours of exposure
o Chronic: insidious breathlessness, weight loss, progression to fibrosis
• Investigations:
o HRCT: ground-glass changes, centrilobular nodules
o Serum precipitating IgG antibodies
o Lung biopsy: poorly formed non-caseating granulomas
• Management:
o Antigen avoidance
o Steroids for severe or persistent symptoms
• Pathology: non-caseating granulomas affecting lungs and multiple organs
• Respiratory:
o Bilateral hilar lymphadenopathy (classic)
o Pulmonary infiltrates
• Extra-pulmonary:
o Skin: erythema nodosum, lupus pernio
o Eye: uveitis
o Hypercalcaemia (macrophage-mediated vitamin D activation)
o Neurological: cranial nerve palsies (esp. CN VII)
• Lab:
o ↑ ACE levels (non-specific)
o ↑ serum calcium
o Restrictive PFT pattern ± reduced DLCO
• Syndromes:
o Lofgren’s syndrome: erythema nodosum, bilateral hilar lymphadenopathy, fever, arthralgia (good prognosis)
o Heerfordt’s syndrome: uveitis, parotid enlargement, fever, cranial nerve palsy
• Management:
o Observation if asymptomatic
o Steroids if symptomatic or organ dysfunction
• Population: young adult smokers (20–40 years)
• Clinical:
o Dry cough, dyspnoea
o Recurrent pneumothorax (due to cyst rupture)
o Diabetes insipidus (if pituitary stalk involvement)
• Imaging:
o Nodules and cysts, upper/mid-lung predominance
o Sparing of costophrenic angles
• Management:
o Smoking cessation (may halt progression)
o Lung transplant in advanced cases
• Common culprits:
o Amiodarone: also causes hyper/hypothyroidism
o Methotrexate: monitor lung function
o Nitrofurantoin: especially with chronic use
o Bleomycin
o Cyclophosphamide
• Presentation:
o Dry cough, dyspnoea
o Restrictive pattern on PFTs
• Management:
o Stop offending drug
o Consider steroids
Extra Revision Pearls
• Honeycombing on HRCT → think UIP/IPF
• Upper-lobe predominant fibrosis → sarcoidosis, hypersensitivity pneumonitis, Langerhans cell histiocytosis, silicosis, TB
• Lower-lobe predominant fibrosis → IPF, asbestosis
• ACE levels are raised in sarcoidosis but not specific; may also rise in TB and lymphoma
• Clubbing common in IPF, rare in sarcoidosis
• Recurrent pneumothorax in young smoker → think Langerhans cell histiocytosis
• Lofgren’s syndrome in sarcoidosis → excellent prognosis; usually resolves spontaneously
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Author & Educational Disclaimer
Author:
Dr Phillip Cockrell BM FRCP DipClinEd
Dr Phillip Cockrell is a UK Consultant Physician in Internal Medicine, currently working at Queen Alexandra Hospital, Portsmouth University Hospitals NHS Trust. He has previously worked as a registrar across Intensive Care Medicine, Gastroenterology, Cardiology, Stroke Medicine, Acute Medicine, and Respiratory Medicine.
He has held senior leadership roles including Associate Clinical Director of the Acute Medical Unit, Clinical Director of Internal Medicine, and Chief of Medicine. Dr Cockrell has over 15 years’ experience in postgraduate medical education, having lectured extensively across the MRCP syllabus and contributed to MRCP revision teaching and course development.
Dr Cockrell holds a Bachelor of Medicine (BM), Fellowship of the Royal College of Physicians (FRCP), and a Diploma in Clinical Education (DipClinEd). His teaching approach is based on structured consolidation of complex medical topics to support efficient and effective revision for postgraduate examinations.
Purpose of this content:
The material on this page is intended solely for educational purposes to support revision for the MRCP (UK) Part 1 examination. It reflects examination-relevant principles of internal medicine and is designed to aid learning and pattern recognition.
Medical disclaimer:
This content is designed for postgraduate medical examination revision and does not constitute medical advice, diagnosis, or treatment guidance and must not be used as a substitute for professional clinical judgement, local guidelines, or specialist consultation. Clinical decisions should always be made in the context of individual patient circumstances and current national guidance.
