A case of undifferentiated connective tissue disease: is it a distinct clinical entity?

Background: In November 2001, a 24-year-old woman with thrombocytopenia and Raynaud's phenomenon presented to our clinic. Her physical examination was unremarkable except for bruising on her legs and arms.

Investigations: Laboratory assays detected the presence of antinuclear and anti-ribonucleoprotein antibodies. Tests for antibodies to double-stranded DNA and for antiphospholipid (lupus anticoagulant and anticardiolipin), anticentromere, anti-Scl-70, and antiplatelet antibodies were negative, as was a Coombs test. An echocardiogram, chest X-ray, and abdominal scan showed no abnormalities. Nailfold digital capillaroscopy revealed minor capillary changes not specific for scleroderma.

Diagnosis: Undifferentiated connective tissue disease.

Management: The patient was successfully treated initially with high doses of corticosteroids and azathioprine, followed by rapid dose tapering. Therapy was continued for 2 years and then stopped. Over the next 4 years the patient's disease history was unremarkable, apart from mild Raynaud's phenomenon of the hands and the presence antinuclear and anti-ribonucleoprotein antibodies. The diagnosis of undifferentiated connective tissue disease was confirmed at her most-recent assessment, in October 2007.