Mixed Connective Tissue Disease

Mixed connective tissue disease (MCTD) is an autoimmune overlap syndrome. A patient may show features of systemic lupus erythematosus, systemic sclerosis, polymyositis or dermatomyositis, and Sjögren syndrome rather than fitting neatly into one connective-tissue disease. High-titre anti-U1 RNP antibodies are the characteristic serologic association. The first clinical clue is often Raynaud phenomenon: fingers become pale or white with vasospasm, then blue as blood flow remains reduced, and finally red as perfusion returns. Puffy, swollen fingers may accompany the episodes and can later develop tighter, thickened skin. This combination is more suggestive than Raynaud phenomenon alone. The same immune process can affect several tissues: - Inflammatory muscle involvement produces symmetrical proximal weakness, such as difficulty climbing stairs, rising from a chair, or lifting the arms. - Systemic sclerosis-like involvement can cause skin tightening, digital ulcers, and oesophageal dysmotility. - Pulmonary disease may involve the interstitium or pulmonary vasculature, causing progressive exertional dyspnoea, reduced exercise tolerance, or hypoxaemia. - Lupus-like disease may produce inflammatory arthritis, serositis, cytopenias, or renal involvement. - Sjögren-like disease may cause dry eyes and dry mouth. The nurse...