Case Presentation: A 46-year-old female presented for evaluation of two days of nausea and vomiting. She also described swelling in her legs and decreased urination over that time. Exam revealed blood pressure of 150/100 (baseline blood pressure 90/50), pitting lower extremity edema, taut skin of both hands, and bibasilar crackles. Labs revealed creatinine of 3.2 mg/dL (baseline 0.8), hemoglobin of 8.9 g/dL (baseline 12.6), and platelet count of 113 x 109/L (previously 492 x 109/L). Peripheral blood smear revealed 3+ schistocytes. Urinalysis showed 2+ protein. Further history revealed that one month prior she had been diagnosed with systemic sclerosis with limited cutaneous involvement and started on mycophenolate mofetil, with minimal change in her clinical symptoms.
Discussion: Acute kidney injury, thrombocytopenia, and hemolytic anemia are separate problems commonly encountered in the hospital setting. In combination, however, these diagnoses represent a limited subset of diseases. While thrombotic thrombocytopenic purpura or hemolytic uremic syndrome may initially be high in the differential diagnosis for this patient’s presentation, in a patient with a history of systemic sclerosis it is essential to recognize scleroderma renal crisis as a disorder that can present with these same findings. It affects approximately 4% of patients with systemic sclerosis with limited cutaneous disease. The differentiation between these diseases is critical, as management is vastly different and time sensitive.
While there is no validated definition of scleroderma renal crisis, a consensus classification has been proposed. This includes new onset hypertension (blood pressure > 140/90) and at least one associated feature (> 50% increase in serum creatinine over baseline, proteinuria, thrombocytopenia, hemolysis, or hypertensive encephalopathy) in patients with systemic sclerosis. Rather than pursuing plasma exchange for treatment of thrombotic thrombocytopenic purpura or providing supportive care alone for hemolytic uremic syndrome, our patient was started on captopril. Prompt blood pressure control, before irreversible renal damage has occurred, is the mainstay of treatment for scleroderma renal crisis. Captopril is recommended initially, as it has the advantages of rapid onset and short duration of action, allowing for rapid dose titration. The goal of initial antihypertensive therapy is returning the patient to previous baseline blood pressure within 72 hours. If left untreated, patients can rapidly progress to end-stage renal disease.
Conclusions: Although thrombotic thrombocytopenic purpura or hemolytic uremic syndrome may more frequently cause the combination of acute kidney injury, thrombocytopenia, and hemolytic anemia in the hospital setting, it is imperative that hospitalists recognize scleroderma renal crisis as a rare presentation of these findings. If they do, they will be able to prevent further renal damage in affected individuals by prompt treatment with antihypertensive medication, and thus improve outcomes for their patients.