What are the key clinical features to consider when diagnosing a patient with suspected connective tissue disease?

When diagnosing a patient with suspected connective tissue disease (CTD), key clinical features to consider include a combination of systemic symptoms and organ-specific manifestations. Systemic symptoms often include fatigue, fever, weight loss, and arthralgia or arthritis, which may present as symmetrical joint pain and swelling. Skin changes are critical, such as Raynaud's phenomenon, skin thickening or tightening (notably in systemic sclerosis), photosensitive rashes (as seen in lupus), and mucosal ulcers. Musculoskeletal involvement may manifest as myalgia, muscle weakness, or inflammatory arthritis. Vascular features like digital ulcers or telangiectasia are important, especially in systemic sclerosis. Respiratory symptoms such as dyspnoea or cough may indicate interstitial lung disease associated with CTD. Renal involvement can present as proteinuria or hypertension, particularly in lupus nephritis. Neurological symptoms including peripheral neuropathy or central nervous system involvement may also be present. Serological markers and autoantibodies support diagnosis but clinical features remain paramount in initial assessment NICE NG100 Fernandez 2019Jerjen et al. 2022Storrer et al. 2024.