Basics
Description
- A rare and poorly understood syndrome characterized by unexplained severe, intermittent or persistent, unilateral or bilateral loin pain with microscopic or gross hematuria
- It is a chronic condition requiring reassurance, careful management of analgesia, and psychological support.
Epidemiology
Incidence
Unknown
Prevalence
- Unknown
- Range: 10 " 60 years
- More common in White female in 20s
Etiology and Pathophysiology
- Uncertain
- Several hypotheses have been proposed such as microvascular abnormalities, complement activation on arterioles, renal vasospasm, veno-caliceal fistula, abnormal ureteral peristalsis, intratubular crystal formation, abnormal platelet function, or psychogenic nature.
- Abnormal glomerular basement membrane (too thick or thin) was found in 60% of 34 patients.
- It is postulated that structurally abnormal glomerular basement membrane may lead to the rupture of glomerular wall and passage of red blood cell (RBC) into the urinary space, which may cause tubular obstruction and back leak of glomerular filtrate with resultant parenchymal edema and stretching of renal capsule.
Genetics
No report of genetic involvement.
Risk Factors
Unknown
General Prevention
N/A
Commonly Associated Conditions
Somatoform disorder (medically unexplained physical symptoms)
Diagnosis
History
- Flank pain is characterized as severe, unilateral or bilateral, persistent or recurrent. The duration is variable and may persist for months. Pain may radiate to groin area such as renal colic and may be associated with nausea and vomiting or dysuria.
- Hematuria can be intermittent, microscopic, or gross.
Physical Exam
- Unremarkable exam or
- Low-grade fever, CVA tenderness
Differential Diagnosis
- A diagnosis should be made after a thorough evaluation and exclusion of alternative etiologies such as
- Obstructive or nonobstructive nephrolithiasis
- Adult polycystic kidney disease
- Renal cell cancer
- Recurrent papillary necrosis
- Recurrent renal thromboembolism
- Recurrent renal vein thrombosis
- Nutcracker syndrome
- Factitious hematuria
Diagnostic Tests & Interpretation
Initial Tests (lab, imaging)
- Kidney function should be normal.
- Urinalysis (UA) shows more than 5 RBC/HPF but may be absent during pain-free period.
- The presence of dysmorphic RBC or RBC casts is possible but not necessary.
- The spot urine protein to creatinine ratio should be normal (<0.3).
- CT of abdomen with/without contrast should be negative for pathology.
- Urine culture should be obtained and negative.
Follow-up tests & special considerations
Psychiatric/psychological evaluation for depression, anxiety, drug addiction, psychosocial stressors, and underlying psychopathology. It is unclear if psychiatric conditions are the cause or the result of pain.
Diagnostic Procedures/Other
Kidney biopsy may be considered in the presence of proteinuria to exclude renal pathology.
Test Interpretation
- No consensus on validated diagnostic criteria.
- All standard hematologic and chemistry evaluation should be normal.
Treatment
General Measures
- Controversial
- This being a rare disease, well-designed clinical trials are lacking. Most of the recommendations are based on observational studies, small case series, and anecdotal reports.
- A multidisciplinary approach consisting medical management and cognitive behavioral therapy should be exhausted prior to invasive or surgical interventions (1,2)[C].
Medication
First Line
Nonopioid analgesic and adjuvant analgesics including antidepressant in combination with an angiotensin-converting enzyme inhibitor (ACEI). ACEI was believed to reduce the frequency and severity of the episodes of gross hematuria and flank pain by reducing glomerular hydrostatic pressure (1,2,3)[C].
Second Line
Opioid-type analgesics
Issues for Referral
- Pain management specialist
- Psychiatrist/psychologist
- Urologist
Additional Therapies
Hypnotherapy (4)[C]
Surgery/Other Procedures
- Intrathecal morphine pump (1,2)[C]
- Transcutaneous electrical nerve stimulation (1,2)[C]
- Percutaneous regional nerve blocks of splanchnic, intercostal, or celiac nerve (1,2)[C]
- Catheter-based renal denervation (1,2)[C]
- Surgical sympathectomy with renal capsulotomy (1,2)[C]
- Renal autotransplantation of the involved kidney. It is used to preserve renal function and provide sustained relief of intractable pain compared to other procedures. Pain might recur within 2 years or occur in transplanted or contralateral kidney (1,2)[C].
Complementary & Alternative Therapies
Nephrectomy should be considered as a last resort.
Inpatient Considerations
Admission Criteria/Initial Stabilization
Pain exacerbation with intractable pain/nausea or vomiting
IV Fluids
In case of poor oral intake
Nursing
Intravenous (IV) or patient-controlled analgesia may be used to control pain.
Discharge Criteria
Pain is under control.
Ongoing Care
Diet
No restrictions
Patient Education
- It is a chronic pain syndrome with medical and psychological aspects.
- Nephrectomy should be considered as a last resort.
Prognosis
- 1/3 of patients will have a spontaneous resolution after a mean of 3.5 years with conservative treatment.
- Kidney function is preserved.
- Hematuria typically persists.
Complications
- High rate of opiate addiction and total disability
- Postprocedure/surgery complications
- Dialysis if bilateral nephrectomy was performed.
References
1.Taba Taba Vakili S, Alam T, Sollinger H. Loin pain hematuria syndrome. Am J Kidney Dis. 2014;64(3):460 " 472.
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2.Smith HS, Bajwa ZH. Loin pain hematuria syndrome " visceral or neuropathic pain syndrome? Clin J Pain. 2012;28(7):646 " 651.
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3.Hebert LA, Betts JA, Sedmak DD, et al. Loin pain-hematuria syndrome associated with thin glomerular basement membrane disease and hemorrhage into renal tubules. Kidney Int. 1996;49(1):168 " 173.
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4.Elkins GR, Koep LL, Kendrick CE. Hypnotherapy intervention for loin pain hematuria: a case study. Int J Clin Exp Hypn. 2012;60(1):111 " 120.
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Additional Reading
- Dube GK, Hamilton SE, Ratner LE, et al. Loin pain hematuria syndrome. Kidney Int. 2006;70(12):2152 " 2155.
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Codes
ICD09
- 789.09 Abdominal pain, other specified site
- 599.70 Hematuria, unspecified
- 599.72 Microscopic hematuria
- 599.71 Gross hematuria
ICD10
- R10.9 Unspecified abdominal pain
- R31.9 Hematuria, unspecified
- R31.2 Other microscopic hematuria
- R31.0 Gross hematuria
SNOMED
- 86208007 Loin pain-hematuria syndrome (disorder)
Clinical Pearls
- A controversial disease with uncertain cause, and pathophysiology
- All standard labs and renal imaging should be normal.
- A diagnosis should be made after a thorough evaluation and exclusion of alternative etiologies.
- Multidisciplinary approach consisting medical management and cognitive behavioral therapy should be exhausted prior to invasive or surgical interventions.