Non-infectious causes of recurrent flank pain in older children

ABSTRACT

To find out the etiology of non-infectious recurrent flank pain in older children. The medical records of 84 consecutive children older than 5 years of age with non-infectious flank pain were retrospectively reviewed. Data checked included history, physical examination, laboratory investigations [serum creatinine, uric acid, and calcium], 24 hour urine collection for creatinine, calcium, oxalate, and uric acid, in addition to imaging studies. Those with systemic disease and urinary tract infection [UTI] were excluded. The most common causes of recurrent non-infectious flank pain in older children were crystalluria [59.5%] and urolithiasis [17.8%]. Amongst the crystalluria, hyperoxaluria was the most frequent. Other etiologies included constipation [6.0%], sterile vesicoureteral reflux [6.0%], and pelviureteric junction obstruction [4.7%].Family history was positive for stones in 45% of urolithiasis cases.Renal ultrasonography was adequate for diagnosing all kidney stonesand unenhanced helical computed axial tomography [UHCT] diagnosed ureteral stones with typical renal colic pain radiating to the groin. Constipation was found to be an important, yet overlooked cause of extraurinary flank pain. The most important non-infectious causes of recurrent flank pain in older children were crystalluria, urolithiasis, constipation, pelviureteric junction obstruction, and sterile vesicoureteral reflux. A positive family history of stones played a key role in initiating workup for crystalluria and urolithiasis. Focused histories and physical examinations were important in those cases with constipation as a cause of reversible flank pain