Loin pain hematuria syndrome

As the name of the condition suggests, loin pain hematuria syndrome (LPHS) is characterized primarily by recurrent or persistent loin pain and/or hematuria (blood in the urine). The loin pain is sometimes described as burning or throbbing and may worsen with exercise or when lying in a supine (face upward) position. Although some may only experience pain on one side initially, most people with LPHS will eventually develop bilateral (on both sides) loin pain. During episodes of pain, affected people may also experience nausea and vomiting; a low-grade fever (up to 101°F); and/or dysuria.^[1][2]

The exact underlying cause of loin pain hematuria syndrome (LPHS) is currently unknown. However, scientists have proposed several theories. For example, some cases of LPHS may be due to abnormal glomerular basement membranes, which are the tissues in the kidney that filter blood. If these tissues are abnormal, red blood cells may be allowed to enter the urinary space, leading to both loin pain and hematuria (blood in the urine). Other factors that may lead to the signs and symptoms of LPHS include:^[1][2]

• Blood disorders, called coagulopathies, which impair the bloods ability to clot
• Spasms in the kidney's blood vessels which may restrict blood flow to certain tissues and lead to tissue death

Up to 50% of people affected by LPHS also experience kidney stones. Some scientists, therefore, suspect that the formation of crystals and/or stones in the kidney may also contribute to the condition as they may block or injure the renal tubules (the long narrow tubes in the kidney that concentrate and transport urine).^[1][2]

A diagnosis of loin pain hematuria syndrome is suspected based on the presence of characteristic signs and symptoms, after other conditions that cause similar features have been excluded. Severe hematuria (blood in urine) may be obvious; however, a urinalysis can be performed to detect microscopic levels of hematuria. In some cases, a kidney biopsy may also be recommended to evaluate the structure and function of the kidney.^[2][1]

Treatment of loin pain hematuria syndrome (LPHS) typically consists of pain management. Narcotics or oral opioids may be prescribed to help control pain. Patients with severe pain may need high-dose opioids daily and may occasionally require hospitalization for intravenous pain relievers and control of nausea.^[1][2]

Limited evidence suggests that drugs that inhibit angiotensin may reduce the frequency and severity of episodes of loin pain and severe hematuria. People with debilitating pain who do not respond to other therapies may be offered surgery (i.e. a nerve block, nephrectomy, kidney auto-transplantation); however, surgical treatment of LPHS is controversial as studies suggest that it has limited value for treating recurrent pain.^[1][2]

The long-term outlook (prognosis) for people with loin pain hematuria syndrome (LPHS) is poorly understood. However, it generally does not lead to kidney failure or a shortened lifespan. Unfortunately, the pain associated with LPHS is often severe and may interfere with quality of life. In many cases, pain can only be managed through high doses of pain relievers and/or hospitalization.^[1][2]