Diagnosed With Polymyalgia Rheumatica? Make Sure.
What Looks Like Polymyalgia Rheumatica May Really Be Systemic Small-Vessel Vasculitis
Posted 5/8/07
New research suggests that some people diagnosed with polymyalgia rheumatica (PMR) actually may have systemic small-vessel vasculitis (SSV), which is inflammation of the body’s small blood vessels, including capillaries and small veins. If left untreated, SSV can lead to kidney failure, which weakens bones, affects the heart and requires dialysis or a transplant. The misdiagnosis occurs because SSV and PMR share symptoms, including achy and stiff upper arms, neck and thighs.
The new study found 15 percent of people who were diagnosed with PMR actually had SSV. “The main consequence of misdiagnosis is lost time in getting appropriate immunosuppressive therapy [for SSV], which may result in some permanent loss of kidney function in addition, of course, to being unwell longer,” says study author Ken Farrington, MD, a nephrologist at the Lister Hospital in Stevenage, England.
But there’s no reason to panic. “PMR is much more prevalent than systemic vasculitis,” says Dr. Farrington. “It is not uncommon to find patients who have systemic vasculitis and were previously diagnosed with PMR, but this subgroup is small,” he explains.
Doctors differentiate PMR and SSV in several ways. There is no single test to diagnose PMR. Patients with PMR typically respond rapidly to moderate doses of steroids; suspicions should be aroused when this does not happen, says Dr. Farrington. SSV is not treated with steroids alone but rather a combination of steroids and cyclophosphamide (Cytoxan), which suppresses the immune system and interferes with the function of the cells that cause the inflammation of the blood vessels. Other tests pointing to SSV include blood and/or protein in the urine, abnormal routine blood tests and evidence of other solid organ involvement.
If you’ve been diagnosed with PMR and have abnormal blood or urine tests, ask if your doctor has already evaluated you for SSV.
Arthritis Today, May-June 2007
