Mixed connective tissue disease (MCTD)

• SLE features (malar rash, photosensitivity, ulcers), scleroderma features (skin thickening, Raynaud's) and myositis (weakness, raised CK).

• Investigations: ANA, high-titre anti-U1 RNP, CBC, CK, ESR/CRP, anti-DNA, echocardiogram, lung function tests, urinalysis.

Management

• Education on flares, sun protection, regular follow-up.

• A: Prednisone 0.5–1 mg/kg/day, tapered (first-line).

• S: Methotrexate 10–25 mg weekly, OR S: azathioprine 1.5–2.5 mg/kg/day, OR S: hydroxychloroquine 200–400 mg daily (SLE features), OR S: cyclophosphamide 500–1000 mg/m² IV every 4 weeks.