Renal infarction in a child with systemic lupus erythematosus.
Although patients with systemic lupus erythematosus (SLE), especially those with antiphospholipid antibodies, have a high incidence of arterial and venous thrombotic manifestations, renal infarction has been rarely reported in these patients and is probably underestimated. A 9-year-old boy with renal infarction, diagnosed by computed tomography and scintigraphy, is described. Initially he complained of severe flank pain; he had no urinary abnormalities and his blood pressure was normal. No evidence of systemic disease was found. He responded well to antibiotic treatment without the need for immunosuppressive therapy. In subsequent years he presented a spectrum of clinical symptoms, including fever, malaise, arterial hypertension headache, and mononeuritis multiplex, accompanied by an increased erythrocyte sedimentation rate and transitory proteinuria. This suggested vasculitis involving peripheral vessels as well as the central nervous system. Treatment with oral prednisone and azathioprine led to remission. Four years after the renal infarction, the child presented with recurrence of systemic disease. The diagnosis of SLE was established, with positive antiphospholipid antibodies. The sudden appearance of severe unexplained flank pain should alert the clinician to a possible underlying renal vessel thrombosis. Renal venous thrombosis is probably much more common; however, renal arterial thrombosis and infarction in association with SLE with positive antiphospholipid antibodies should be added to the differential diagnosis.