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In our latest Clinical Problem-Solving article, a 41-year-old man presented to the ED with abdominal pain. The pain was excruciating and sudden in onset, originating in his right lower quadrant and radiating to his right groin and flank. He reported nausea and one episode of nonbloody, nonbilious emesis.
The initial evaluation of a patient with acute abdominal pain should focus on identifying life-threatening causes and surgical emergencies such as cholecystitis, aortic dissection, mesenteric ischemia, and bowel perforation.
Clinical Pearls
The primary vasculitides that typically affect the kidney include granulomatosis with polyangiitis (formerly known as Wegener’s polyangiitis), polyarteritis nodosa, Henoch-Schonlein purpura (also known as IgA-associated vasculitis), microscopic polyangiitis, and cryoglobulinemic vasculitis. An absence of inflammation in the urinary sediment argues against vasculitides with arteriolar or capillary involvement (e.g., granulomatosis with polyangiitis), since in these conditions renal involvement is manifested as glomerulonephritis.
The five-factor score (for the presence of proteinuria at >1 g of protein per day, creatinine level >1.58 mg per deciliter [139.7 micromoles per liter], cardiomyopathy, severe gastrointestinal involvement [e.g., bleeding or infarction], and central nervous system involvement) is a prognostic tool that can be used to inform treatment decisions for a number of vasculitides, including polyarteritis nodosa. Single-agent (glucocorticoid) therapy is often used as the initial treatment strategy in patients with a five-factor score of 0, although many of these patients will require an additional agent.
Morning Report Questions
Q: What are the manifestations of polyarteritis nodosa and how is it typically diagnosed?
A: Polyarteritis nodosa is an ANCA-negative vasculitis that typically affects medium-size arteries and may affect any organ system. As is the case with other vasculitides, patients with polyarteritis nodosa typically have systemic symptoms (e.g., fatigue, arthralgias, weight loss, or fever) and may also have neurologic symptoms (peripheral neuropathy or mononeuritis multiplex), skin involvement (nodules [often necrotizing], purpura, or livedo), renal involvement, or a combination of these symptoms. One of the most commonly affected organs is the kidney. There are no formal diagnostic criteria for polyarteritis nodosa. The diagnosis is made on the basis of a constellation of typical symptoms, supportive laboratory tests, and either a biopsy of the affected tissue (i.e., skin, nerve, or muscle tissue — both renal and hepatic biopsies are contraindicated) showing characteristic necrotizing arterial inflammation or visceral angiography showing microaneurysms in the renal, mesenteric, or hepatic vasculature. These aneurysms can be difficult to detect, since they may be small, limited to a single organ or vascular territory, and few in number.
Q: What is the typical treatment of polyarteritis nodosa, and the prognosis if left untreated?
A: Studies suggest that treatment with glucocorticoids alone or in combination with cyclophosphamide or azathioprine induces remission in the majority of patients with polyarteritis nodosa. The specific treatment generally depends on the severity of the disease. Hypertension is a common manifestation of polyarteritis nodosa that can be effectively treated with ACE inhibitors. The prognosis for patients with untreated polyarteritis nodosa is grim, with a 5-year survival rate of 13%; death is often a consequence of renal failure, myocardial infarction, or stroke. With appropriate therapy, the 5-year survival rate is approximately 80%.
