Involvement of lupus enteritis in a patient with lupus cystitis and nephritis.

We present the case of a patient with lupus enteritis accompanied by both lupus cystitis and lupus nephritis without a history of systemic lupus erythematosus. The patient had a 2-month history of diarrhea and pollakiuria and was admitted to our hospital. Physical examination showed abdominal tenderness. Laboratory data revealed reductions in both total protein and albumin, elevated serum creatinine levels, and elevated antinuclear and anti-Smith antibodies. Urinalysis revealed proteinuria. Stool and urine cultures were negative. Abdominal computed tomography revealed diffuse edematous wall thickening, dilatation of the small intestine suggesting paralytic ileus, and irregular wall thickening of the urinary bladder. Histological results of the cystic and renal biopsies revealed interstitial cystitis and membranous nephropathy which were suggestive of lupus cystitis and lupus nephritis, respectively. The patient's gastrointestinal symptoms were finally diagnosed as resulting from lupus enteritis. After initiating 30 mg oral prednisolone daily, the diarrhea and pollakiuria subsided, and renal function became normal. Lupus enteritis should always be considered in the differential diagnosis when patients complaining of chronic diarrhea of unknown etiology are encountered.