Mixed connective tissue disease is an autoimmune disorder that combines features of lupus, systemic sclerosis and myositis, with high levels of anti-U1 RNP antibodies. Most patients do well, but lung disease, especially pulmonary hypertension, is the main cause of death.
Key symptoms
- Raynaud phenomenon: fingers turn white, then blue, in the cold
- Puffy, swollen hands and fingers
- Joint pain and muscle weakness
- Fatigue, trouble swallowing and shortness of breath
What you find on exam
- Swollen sausage-like fingers and skin tightening
- Synovitis of the hand joints
- Proximal muscle weakness
- Lung crackles, or a loud P2 from pulmonary hypertension
Tests
- ANA with a speckled pattern and high anti-U1 RNP
- Creatine kinase, blood count and kidney function
- Echocardiogram and pulmonary function tests to screen for lung disease
- Chest CT if lung disease is suspected
Treatment basics
- Calcium channel blockers such as nifedipine for Raynaud; keep hands warm
- NSAIDs or hydroxychloroquine for joint pain
- Corticosteroids for myositis or serositis
- Immunosuppressants such as methotrexate or mycophenolate; specialist care for pulmonary hypertension
Red flags
- Worsening shortness of breath or exercise tolerance
- Finger ulcers or a finger turning black
- Severe muscle weakness or trouble swallowing
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.