The loin pain-hematuria syndrome (LPHS) was first described in 1967 in a report of three young women (20 to 28 years of age) who had recurrent episodes of severe unilateral or bilateral loin (flank) pain that were accompanied by gross or microscopic hematuria . The major causes of flank pain and hematuria, such as nephrolithiasis and blood clot, were not present (see 'Diagnosis' below). Renal arteriography suggested focally impaired cortical perfusion, while renal biopsy showed interstitial fibrosis and arterial sclerosis.
Since the original report, several hundred cases of LPHS have been reported in the medical literature .
The epidemiology of loin pain-hematuria syndrome (LPHS) is not well understood. Approximately one-half of our more than 200 LPHS patients reside in Central Ohio, which has a population of 1.8 million. If our patients represent one-half of those with LPHS in this region, the prevalence of LPHS is about 0.012 percent. This qualifies LPHS as a rare disease (prevalence less than 0.07 percent) according to the Rare Disease Act of 2002 (House Resolution 4013).
Loin pain-hematuria syndrome (LPHS) is a poorly defined disorder characterized by recurrent or persistent loin (flank) pain and hematuria that appears to represent glomerular bleeding. Most patients present with both manifestations, but some present with loin pain or hematuria alone . Pain episodes are rarely associated with low-grade fever and dysuria, but urinary tract infection is not present .
Affected patients are typically young (mean age 31 years in one review, with some cases occurring in teenage children) women (70 to 80 percent in most series), and almost all white [2-4]. As many as 50 percent of patients with LPHS have nephrolithiasis, as defined by either a history of passing stones or, on imaging studies, renal calcifications typical of stones .