Blood smear with schistocytes. Take our hypertension emergency quiz. Source: Wikipedia

Systemic Sclerosis, Acute Kidney Injury, Hypertensive Emergency – Quiz

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Background:

48-year-old female presents with systemic sclerosis and hypertension. Her blood pressure is 200/105. She just got back from a trip and was given antibiotics and prednisone for bronchitis at an urgent care. The patient is currently taking 20 mg of prednisone. She also notes a headache. Her physical exam reveals thickened skin. The head CT scan was normal.

She gets admitted to the hospital for hypertensive emergency. Her blood reveals that she is anemic; hemoglobin is 10.5. She is found to have schistocytes on the peripheral blood smear (suggesting microangiopathic hemolytic anemia, shown in the figure above). Her creatinine is 1.8 (baseline 1.3), and she is diagnosed with acute kidney injury (AKI). The urinalysis has protein and blood. The urine microscopy shows 0-2 red blood cells. Anti-RNA polymerase III antibody is positive.

Please answer the following questions:

Which of the following is the most likely diagnosis?
* Rapidly progressive glomerulonephritis
* Migraine
* Scleroderma renal crisis

Patients with scleroderma renal crisis are typically normotensive.
A
True
B
False

Anti-RNA polymerase III antibody has no association with renal crisis in systemic sclerosis.
A
True
B
False

Prednisone doses greater than 7.5 mg/d should be avoided in patients with diffuse cutaneous systemic sclerosis to prevent renal crisis.
A
True
B
False

Discussion:

Scleroderma Renal Crisis

Scleroderma renal crisis is a rare but life-threatening condition characterized by new-onset hypertension, microangiopathic hemolytic anemia (schistocytes present, see figure above), creatinine elevation, and proteinuria. Having a high index of suspicion is important, as patients may not always present with high blood pressure. Anti-RNA polymerase III antibody has been linked to renal crisis in systemic sclerosis. So this test can help you. Glucocorticoids, especially at doses over 7.5 mg/d, can trigger this condition, particularly in patients with diffuse cutaneous systemic sclerosis. We suggest avoiding oral corticosteroids to treat acute bronchitis, either because of safety concerns or lack of efficacy.

  • Key features of scleroderma renal crisis: headaches, blurred vision, elevated blood pressure, elevated creatinine, microangiopathic hemolytic anemia, and proteinuria.

Why is this not Migraine?

Migraine is unlikely because of the absence of aura, photophobia, and nausea. It does not account for high blood pressure, microangiopathic hemolytic anemia, and the patient’s acute kidney injury.

Why is this not Rapidly Progressive Glomerulonephritis (RPGN)?

This diagnosis is atypical for this presentation: hypertension and AKI in the setting of diffuse cutaneous systemic sclerosis is more likely to be scleroderma renal crisis. The microscopy did not reveal any red blood cells, making the diagnosis of rapidly progressive glomerulonephritis, RPGN, less likely.

Inspiration: Scleroderma and Renal Crisis

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