Beads on a String

A 41 year old gentleman with no past medical history presented to ER for nausea, vomiting and abdominal pain. Abdominal CT showed bilateral renal infarcts. His labs were notable for a Cr of 1.4, LDH 500 ESR 102.

The commonest causes of renal infarcts are emboli from atrial fibrillation, infective endocarditis, or fat, renal artery or aortic dissection, fibromuscular dysplasia and vasculitis. Work-up including an EKG, ECHO, hypercoagulable panel and antiphospholipid antibodies were all negative. We performed an angiogram which showed diffuse visceral microaneurysms leading to a diagnosis of polyarteritis nodosa.

Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis that affects medium sized vessels. It was first described by Dr. Kussmaul and Dr. Maier in 1866. The incidence of the disease is 2 to 33 per million population, with a male to female ratio of 1.5:1. The major environment factor associated with PAN is HBV infection.

There are 5 variables that predict an increased risk of mortality in PAN (Five factors score FSS): 1) Proteinuria>1g/day

2) Renal insufficiency (Cr>1.58)

3) GI involvement (bleeding perforation, infarction or pancreatitis)

4) Cardiomyopathy

5) Central venous system involvement.

Without treatment, the 5 year mortality in patients with 0 risk factor is <12%, 1 risk factor 25% and 2 risk factors 56%. The standard treatment for FSS>1 is 12 months Cytoxan with steroids. Renal failure is rare in PAN patients and uncontrolled or relapsing vasculitis is the most common cause of death.

In our case, the patient was started on cytoxan and prednisone and his abdominal pain completely resolved. His creatinine unfortunately is still elevated and the plan is to continue with treatment for at least 6 months.

Posted by Jie Cui