Hyperrenin-hyperaldosterone-dependent malignant hypertension in polyarteritis nodosa.

We have described a patient, subsequently found to have polyarteritis, whose renin activity was 60 times normal, a level associated with malignant hypertension and severe renal artery stenosis. The severe hypertension and its resistance to multiple medications in the face of a dramatic response to low-dose enalapril imply the renin-angiotensin system was the primary pathophysiologic mechanism. We believe renin activity should be measured in hypertensive patients with polyarteritis. Furthermore, PAN should be in the differential diagnosis of hyperreninemic hypertension. ACE inhibitors should be strongly considered in the management of classical PAN-induced hypertension.