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This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
Key points
- Always ask about OCCUPATIONAL HISTORY in any patient with respiratory symptoms
- Asbestosis: interstitial fibrosis from asbestos exposure; pleural plaques are benign markers of exposure
- Mesothelioma: malignant tumour of the pleura (or peritoneum) — almost always asbestos-related; median survival ~12 months
- Occupational asthma: asthma caused or worsened by workplace sensitisers (isocyanates, flour, wood dust) — symptoms improve on holidays/weekends
- Patients may be entitled to Industrial Injuries Disablement Benefit (IIDB) compensation
Overview
Occupational lung disease encompasses a group of conditions caused or exacerbated by inhalational exposures at work. Key conditions include: asbestosis (diffuse interstitial fibrosis from asbestos), pleural plaques (benign markers of asbestos exposure, NOT pre-malignant), mesothelioma (malignant tumour of the pleura/peritoneum), silicosis (progressive massive fibrosis from silica dust), coal workers’ pneumoconiosis, byssinosis (cotton dust), extrinsic allergic alveolitis/hypersensitivity pneumonitis (organic dust), and occupational asthma. A thorough occupational history is essential in any patient presenting with respiratory symptoms.
Epidemiology
Occupational factors contribute to approximately 15% of COPD and 9–15% of adult-onset asthma. Mesothelioma incidence peaked in the UK around 2020 (reflecting asbestos use peak in the 1970s), with approximately 2,700 deaths per year. The latency period for mesothelioma is 20–50 years from exposure. Occupational asthma is the commonest occupational lung disease in the UK — isocyanates (paint sprayers), flour and grain dust (bakers), wood dust (carpenters), and laboratory animals are the most common causes. Silicosis remains a concern in construction, quarrying, and sandblasting.
Clinical Features
Symptoms
Progressive breathlessness (asbestosis, silicosis, CWP)
Dry cough (fibrosis) or productive cough (CWP, silicosis)
Chest pain and breathlessness (mesothelioma — often with pleural effusion)
Occupational asthma: wheeze and cough that improve on days off work and holidays
Unexplained weight loss (mesothelioma)
Signs
Bibasal fine crackles (asbestosis — similar to IPF)
Finger clubbing (asbestosis, mesothelioma)
Signs of pleural effusion (mesothelioma)
Progressive massive fibrosis: upper lobe fibrosis (silicosis, CWP)
Investigations
First-line
Detailed occupational historyESSENTIAL — dates, duration, specific substances, use of protective equipment
Chest X-rayPleural plaques (calcified), interstitial fibrosis, upper lobe fibrosis (silicosis), pleural effusion or thickening (mesothelioma)
Spirometry and TLCORestrictive pattern in fibrosis; obstructive in occupational asthma; reduced TLCO in diffuse disease
Second-line
HRCT thoraxMore sensitive than CXR for interstitial fibrosis, pleural disease, and early silicosis
Serial peak flow monitoringOccupational asthma: 2–4 hourly readings over 4+ weeks, including work and rest days — OASYS analysis
Specialist
Pleural biopsy (CT-guided or thoracoscopy)For suspected mesothelioma — tissue diagnosis essential
Specific IgE / challenge testingFor occupational asthma — identifies the causative sensitiser
1
General principles
- Remove or minimise exposure — redeployment if occupational asthma confirmed (early removal improves prognosis)
- Notify: report confirmed cases to employer and HSE via RIDDOR
- Compensation: patients may be eligible for IIDB for prescribed diseases (asbestosis, mesothelioma, silicosis, occupational asthma)
2
Asbestosis and pneumoconiosis
- No specific treatment for established fibrosis
- Supportive: pulmonary rehabilitation, supplemental oxygen, manage complications
- Monitor for malignancy (increased risk of lung cancer and mesothelioma with asbestosis)
3
Mesothelioma
- Median survival ~12 months from diagnosis
- Chemotherapy: pemetrexed + cisplatin (modest survival benefit)
- Palliative: symptom control, recurrent effusion management (IPC or pleurodesis)
- Patients may claim compensation through IIDB and civil litigation
4
Occupational asthma
- Early diagnosis and removal from exposure = best prognosis
- Treat as per standard asthma guidelines (BTS/SIGN)
- If exposure continues, even with respiratory protection, condition typically worsens
Complications
- Lung cancer: Asbestos exposure increases lung cancer risk 5× alone, 50× with smoking (synergistic)
- Mesothelioma: Almost invariably fatal; no cure
- Progressive massive fibrosis: Silicosis and CWP can progress to large fibrotic masses
- Respiratory failure: End-stage fibrotic disease
- TB: Silicosis increases TB risk 3–30× (silica impairs macrophage function)
UKMLA Exam Tips
- 1ALWAYS ask about occupational history — it changes diagnosis, management, and compensation
- 2Pleural plaques = benign marker of asbestos exposure, NOT pre-malignant, do NOT cause symptoms
- 3Asbestosis + smoking = synergistic risk for lung cancer (multiplicative, not additive)
- 4Mesothelioma: asbestos exposure + pleural thickening/effusion + chest pain — median survival ~12 months
- 5Occupational asthma improves on weekends/holidays — key distinguishing feature from non-occupational asthma
- 6Silicosis: "eggshell calcification" of hilar lymph nodes on CXR is classic
- 7Silicosis increases TB risk — think TB in any silicosis patient with worsening symptoms
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