Patient With a Rash, Abdominal Pain, and Weight Loss FREE

A 49-year-old man presents with right iliac fossa pain of 36 hours' duration. He reports loss of appetite, weight loss, and increasing lethargy over the preceding 10 months with intermittent constipation but no other symptoms. He describes asymmetric altered sensation in his distal lower limbs with left worse than right. The patient smokes, has a history of illicit amphetamine and cannabinoid use, and acquired tattoos in a correctional facility. Past medical history is remarkable for an idiopathic splenic infarction 6 months ago. On physical examination, he is cachectic and he has right iliac fossa tenderness and percussion tenderness. He has a demarcated, erythematous maculopapular rash across his torso and limbs (Figure 1). Neurological examination reveals an asymmetric lower limb sensory neuropathy.

Laboratory findings include leukocytosis (white blood cells, 16 900/μL), elevated inflammatory markers (C-reactive protein, 109 g/L; erythrocyte sedimentation rate, 27 mm/h), elevated rheumatoid factor (269 IU/L), low C3 and C4 (0.24 and <0.05 g/L, respectively), and a low titer of atypical perinuclear antineutrophil cytoplasmic antibody (ANCA), not selective for either proteinase 3 or myeloperoxidase. Double-stranded DNA and extractable nuclear antibodies are negative. Cryoglobulins and serology for human immunodeficiency virus, hepatitis B, and hepatitis C are negative. Renal function is normal with normal urinary sediment. Abdominal computed tomography reveals mild thickening of the ascending colon and the previously documented splenic infarction (Figure 2).

Polyarteritis nodosa (PAN)

D. Request a surgical consultation for diagnostic laparoscopy

The key clinical feature is an acutely tender abdomen in a patient with multisystem disease and previous idiopathic visceral infarction. PAN represents an uncommon but important cause of visceral ischemia and infarction. Vasculitis should be included in the differential diagnosis of patients presenting with multisystem clinical phenomena.

PAN is a vasculitis involving medium-sized arteries. It is rare, affecting fewer than 30 people per million.¹ PAN has characteristic cutaneous manifestations and typically affects visceral organs (kidney, spleen, bowel), sparing the pulmonary vascular bed. Patients are usually ANCA negative. The presence of either proteinase 3 or myeloperoxidase ANCA supports an alternative diagnosis. Approximately one-third of cases are associated with hepatitis B infection, absent in this patient.² Pathogenesis involves immune complex deposition within the intima of medium-sized arterial vasculature.

In this patient with an acutely tender abdomen and multisystem disease with previous idiopathic visceral infarction, a laparoscopic exploration is reasonable. A dermal punch biopsy would aid in characterizing the rash, although laparoscopy would take precedence with suspected intestinal ischemia. Colonoscopy may be unsafe with a differential including intestinal ischemia. Nerve conduction studies would document the peripheral neuropathy and distinguish axonal from demyelinating, but not contribute further to the final diagnosis.

At laparoscopy, the ascending colon was ischemic and nonviable, with a circumferential stricture at the proximal margin of the ischemic segment. A right hemicolectomy was performed (Figure 3A). Histopathology revealed intimal hyperplasia and patchy cellular inflammatory changes of the medium-sized arterial vessels, with sparing of venous structures (Figure 3B). Transthoracic echocardiography revealed no focus for embolic phenomena. Computed tomography angiography of mesenteric vessels confirmed aneurismal dilatations at the bifurcation of vessels in the vascular bed.

A diagnosis of PAN was made, with acute on chronic mesenteric ischemia, previous splenic infarction, chronic abdominal pain, weight loss, and malnutrition.

This patient was treated with high-dose oral corticosteroids, resulting in rapid clinical and serological improvement. Cyclophosphamide may be considered in patients responding incompletely to glucocorticoids.

The cutaneous features of PAN typically include livedo reticularis, nodules, papules, ulcerations, and digital ischemia predominantly affecting the lower limbs. The features in this patient are not typical of PAN and may represent a toxic erythematous drug reaction, potentially to contaminants of illicit substances such as levamisole, a commonly used adjuvant in illicit cocaine.