- Develop a framework for approaching a patient with purple fingers and toes
27 year old woman two months of diffuse polyarticular arthralgias and progressive fatigue along with three weeks of intermittent purple fingers and toes that are now persistent and painful. She has also reported new shortness of breath along with dark, decreased urine output for the past few days. Tested positive for rheumatoid factor 4 weeks ago. No medications. Non-smoker, no illicit drug use. No family history of rheumatologic, hypercoagulable or autoimmune disease.
On exam she is afebrile, HR 140bpm, BP 110/70, 96% on 2L nasal cannula. Appears to be in severe pain, tachycardic but regular, bibasilar crackles to auscultation, skin is cool with the below findings.
BUN 30, Cr 3, WBC 20, Hct 19 (MCV 79), albumin 1.9, ESR >140, Trop 0.8
UA: protein, RBC casts
Granulomatous Polyangitis (GPA) with pulmonary-renal syndrome and distal extremity necrosis
There was high suspicion for RPGN based on the patient’s elevated creatine with active sediment including RBC casts. This narrowed the likely differential to pauci-immune small vessel vasculitis (GPA, MPA and EGPA), cryoglobulinemia and antiphospholipid syndrome (APLS), as conditions that would explain acutely necrotic distal extremities and RPGN. She had highly elevated cANCA and PR3. Her additional work-up was unremarkable. She was started on high dose steroids overnight and cyclophosphomide the next morning. She avoided dialysis and ultimately discharged 8 days later with all ten fingers and toes.
Hirschmann, Jan V., and Gregory J. Raugi. “Blue (or Purple) Toe Syndrome.” Journal of the American Academy of Dermatology, vol. 60, no. 1, 2009, pp. 1–20.