Cutaneous nerves in the sole (foot)
From Gray’s Anatomy
Diagram drawn by Mysid
Gray’s Anatomy is in the public domain because of copyright expiration
Ask someone with active lupus the question, “Where does it hurt?” and the reply may be, “Just about everywhere”. Pain, with lupus and many other chronic conditions, becomes a backdrop to daily routine; only if pain spikes, or changes, is one likely to take note. In this setting, peripheral neuropathy (PN)–which often signals its presence by causing pain–can be easily misdiagnosed. An article published in the online journal, medpage today reports that though PN often occurs in conjunction with SLE, the two diseases have such similar symptoms that SLE may mask the presence of PN. It is a patient who is best able to detect early signs of neuropathy; significant changes in pain or sensation should be reported to a healthcare provider.
Peripheral Neuropathy is a disease of the nervous system. The Neuropathy Association describes PN as “…a disorder of the peripheral nerves—the motor, sensory and autonomic nerves that connect the spinal cord to muscles, skin and internal organs.” The symptoms include not only pain, but, among other things, tingling, burning, loss of sensation and muscle weakness. The disorder is often progressive and can be disabling; in some cases it leads to paralysis, loss of bowel function and even amputation. According to the Mayo Clinic, early treatment of PN offers the best chance for heading off more serious developments.
Dr. Franz Blaes, of the Grummesbach Hospital in Germany, describes the dilemma facing a physician treating someone who has both PN and an inflammatory rheumatological disorder, such as SLE or Sjogren’s Syndrome: “Patients can be classified neither as a rheumatic disease patient, nor as a patient with a neurological syndrome, but as both,” Dr. Blaes explains. The key to treatment, he suggests, is to get a clear picture of exactly what is going on. Is it PN, SLE, Sjogen’s, or a combination of conditions? Treatment is prescribed based on what this process reveals. In most cases where both the inflammatory rheumatological disease and PN exist, steroids are an effective intervention. However, regimens involving IVG therapy, plasmapherisis, cyclophosphamide and Rituximab may also be prescribed.
The most important thing SLE patients can do to help themselves, if there is a suspicion that PN is present, is to read the literature. Understand the tests that are given and what the results indicate; be aware of the kind of PN that is suspected; learn about treatment options, especially the one that is prescribed for your case. An article published in the September 2013 issue of Rheumatologist–Tips for Managing Peripheral Neuropathy in Rheumatic Disease by Timothy Collins–gives a good overview of peripheral neuropathy in SLE.
How does a doctor go about diagnosing PN, especially if someone also has an underlying inflammatory condition? According to Dr. Collins, this is not an easy task. The first step is to do a lab workup, including creatinine, complete blood count and liver enzymes. From these studies a doctor might eliminate some possible causes of the PN, such as diabetes. After getting the results from these tests, a doctor may turn to electrodiagnoistic studies. These help to determine the type of neuropathy and also may indicate the kind of underlying pathology that is causing the condition. A third kind of study that is sometimes suggested carries greater risk and often yields inconclusive results: nerve biopsy. According to Dr. Yvonne Lee of the Harvard Medical School, this “...shouldn’t be done before adequate clinical, laboratory, and electrophysiologic studies have been done.1 Results are often nonspecific, and complications, such as sensory loss and/or unpleasant abnormal sensations, are common.
Quality of life studies show that SLE patients with PN tend to score lower on quality of life metrics . This outcome is similar to other assessments of SLE patients who have central nervous system involvement.
Peripheral neuropathy is a serious condition; when it appears with SLE it may be overlooked or misdiagnosed. Sometimes PN may be the first noticeable symptom of SLE. Because the research on the relationship between PN and SLE is relatively recent, some doctors may not be alert to the issue.
The bottom line is this: if you have SLE and unexplained pain, PN is a possibility–one of many possibilities. In the past, rheumatologists believed this disorder was not likely to be seen in SLE patients; research is disproving this perception.
For most people with SLE, pain is simply a fact of life. But pain can be an important symptom and if there is a change in how it is experienced, then that should be noted. Perhaps the source of pain will not be discovered; perhaps the pain will not be alleviated. This may be a reality that a patient has to accept. However, one reality no one ever should accept is that pain, when reported, is disregarded. That course is irresponsible and even dangerous