33-year-old woman with mixed connective tissue disease and rapid onset breathlessness

We present a 33-year-old woman with anti-U1 ribonucleoprotein antibody positive mixed connective tissue disease (MCTD) since the age of 13. Predominant features were of inflammatory arthritis, Raynaud’s phenomenon and fatigue. She had been stable on combined methotrexate and hydroxychloroquine.