Synopsis
Detect interstitial lung disease linked to systemic autoimmunity, recognise rapidly progressive phenotypes and coordinate respiratory and rheumatology treatment without obscuring infection or medicine toxicity.
- Connective-tissue disease may precede ILD, appear concurrently or emerge after lung disease, so absence of a previous rheumatology diagnosis is not exclusion.
- Systemic sclerosis, rheumatoid arthritis, inflammatory myopathy, Sjögren disease, mixed connective-tissue disease and lupus produce different patterns and risks.
- Ask about Raynaud phenomenon, digital ulcers, skin tightening, inflammatory joints, sicca, dysphagia, reflux, photosensitive rash, proximal weakness and mechanic's hands.
- NSIP is a common CTD-ILD pattern; UIP is especially important in rheumatoid arthritis, while organising pneumonia and lymphoid interstitial pneumonia occur in selected contexts.
- Serology supports a clinically coherent phenotype but does not replace examination, HRCT interpretation or multidisciplinary discussion.
- Rapidly progressive myositis-associated ILD can deteriorate over days to weeks even when muscle symptoms or creatine kinase elevation are limited.
- Before escalating immunosuppression, consider bacterial, viral, fungal and opportunistic infection, particularly after corticosteroids or multiple agents.
- In systemic sclerosis, corticosteroid exposure—especially higher doses—requires specialist caution because of scleroderma renal crisis risk.
- Treatment targets inflammatory activity, fibrosis or both; the connective-tissue disease, HRCT behaviour, physiology and comorbidities determine the regimen.
- Joint respiratory-rheumatology follow-up should track lung function, extrapulmonary activity, drug toxicity, vaccination, infection prevention and reproductive planning.
Key red flags
Escalating cough, dyspnoea and oxygen requirement over days or weeks with new ground glass or consolidation can occur in inflammatory myopathy and requires urgent specialist assessment.
Haemoptysis may be absent; falling haemoglobin, hypoxaemia and diffuse opacities with vasculitic renal or systemic findings demand emergency respiratory, renal and rheumatology coordination.
Syncope, chest pain, oedema, disproportionate TLCO reduction or breathlessness unexplained by HRCT raises pulmonary vascular disease, myocarditis or ventricular dysfunction and warrants prompt evaluation.
Investigation priorities
Define the systemic phenotype that gives lung findings meaning.
Management branches
ILD is found in known connective-tissue disease or autoimmune clues appear in unexplained ILD.
- Assess oxygenation and tempo, obtain complete physiology and HRCT, and document medication, infection, smoking and exposure histories that could provide alternative explanations.
- Perform a directed rheumatological examination and phenotype-led serology rather than treating a laboratory panel as a diagnosis.
- Discuss the case jointly with ILD radiology and rheumatology, naming pattern, extent, systemic disease confidence and whether inflammation or fibrosis appears dominant.
- Establish a shared monitoring plan and tell the patient which team to contact for respiratory decline, systemic flare or treatment toxicity.