How do you approach evaluation for underlying rheumatologic disease in patients with chronic asymptomatic thrombocytopenia?

APL testing as well as evaluation for SLE and Sjogrens with complement, urine, antibody testing, not just an ANA.

Agree with Dr. @Dr. First Last.

Of course, don't forget about the DDX for drug effect, pseudothrombocytopenia from clumping, infections (like hep C), liver dz, etc.

But focusing on ruling out autoimmune disorders, adding a few Pearls:

On PE look for painless oral ulcers on the palate, discoid lupus hiding in the concha/scalp/intertragal notch.

Order the ANA by IIF (indirect immunofluorescence) and solid phase assay both. This is my practice as it greatly increases sensitivity for SLE dx and is supp...