People with Rheumatoid Arthritis Have More Infections

A recent study published in the September issue of Arthritis and Rheumatism confirmed a long-held belief that people with rheumatoid arthritis have a higher rate infection than those without the disease. Rheumatoid arthritis is a condition that causes the immune system to attack the joints, which leads to swelling, inflammation, and pain. Physicians use medications that suppress the immune system to treat the disease.

Researchers compared the frequency of infection in a population of patients with rheumatoid arthritis to individuals in the same population with out the disease. The researchers studied a geographic population in Rochester, Minn, and found that those with rheumatoid arthritis were 70% more likely to acquire an infection during the study period. Sites of infection with the highest risk ratios were bone, joints, skin, soft tissues, and the respiratory tract

Source: M F Doran et al, "Frequency of infection in patients with rheumatoid arthritis compared with controls: A population-based study," Arthritis and Rheumatism 46 (September 2002) 2287-2293.

Editor's note:
Pain affects the immune system, purportedly by its effects of chronic stress and depression. So do the steroids and other medications used to treat arthritis. Would better pain management reduce the rate of infection in this common and debilitating illness? It would be interesting to re-look at their data to see if these effects could be analyzed.
RM Gallagher, MD, MPH

Diabetic Foot Pain May be Relieved by Medicated Spray

Researchers in the United Kingdom recently published results of a small study that suggests patients with diabetes-related nerve damage may find temporary relief of pain in their feet by using a medicated spray commonly used to treat chest pain.

People with diabetes are at risk of developing neuropathy associated with their disease that causes nerve damage that leads to pain in the legs and feet. Some researchers believe that the neuropathy is related to decreased nitric oxide generation. Nitric oxide aids blood vessels in dilating, which allows blood to flow normally.

The researchers examined the effects of isosorbide dinitrate spray in a double-blind randomized, placebo-controlled study of 22 patients with diabetic-related neuropathy. The isosorbide dinitrate spray imparts nitric oxide and causes blood vessels to widen. At the end of the study, 50% of patients reported that the spray reduced overall neuropathic pain and the burning sensation associated with nerve damage. The researchers conclude that the potential of the spray in alleviating symptoms associated with diabetic peripheral neuropathy should be studied further.

Source: K C Yuen, N R Baker, G Rayman, "Treatment of chronic painful diabetic neuropathy with isosorbide dinitrate spray: A double-blind placebo-controlled cross-over study," Diabetes Care 25 (October 2002) 1699-1703.

Editor's note:
The results of this well-designed study demonstrate once again that there are many new treatments under investigation that can provide relief to persons with chronic pain disorders. People with pain should never give up, and should look for treatments that are demonstrated by good research to be effective.
RM Gallagher, MD, MPH

Reports from the 10th Annual World Congress on Pain

Leading researchers, physicians, health care providers and pain experts from around the world met in San Diego in August to present results of research related to pain and learn from their colleagues' work. Following are just a few highlights from the hundreds of presentations.

Work-related Cost of Pain Estimated at $80 Billion per Year

Researchers from the Center for Work and Health, AdvancePCS, presented results of an audit that estimates the indirect and social costs of common pain conditions in the United States. The researchers interviewed a random sample of 13,254 employed and 856 unemployed adults, ages 18 to 65, to determine the cost of work absence and reduced performance at work as it relates to arthritis, back pain, headache, and other musculoskeletal pain. Using self-reported annual salary, the researchers converted workers' lost productive time to dollars per worker per week.

The researchers concluded that pain from these conditions costs US employers approximately $80 billion per year in lost productivity. Approximately $64 billion of this occurs when workers are on the job but in too much pain to perform adequately, not because they are not at work.

Editor's note:
This extremely valuable study documents once again the severe public cost of chronic pain. From an employer's point-of-view, this study mandates that more is done to help workers control their pain. Other research has shown that more satisfied workers are more likely to return to work after an injury. So job satisfaction is also important in preventing the negative effects of injury and pain on worker productivity.
RM Gallagher, MD, MPH

Lumbar Sympathetic Nerve Blocks May Not Help Back Pain

A researcher from the Center for Pain Rehabilitation, Siskin Hospital, Chattanooga, Tenn, reports that lumbar sympathetic nerve blocks do not reduce pain, improve work and life function, or reduce the use of other medications in patients with chronic low back pain. The researcher evaluated 30 patients with chronic low back pain who received nerve blocks and 30 patients with chronic low back pain who did not. Patients were matched on age, sex, treatment, pain duration, back surgeries and presence and type of pain in the legs. Except for the nerve blocks, both groups underwent the same treatment plan, which included physical therapy and psychological visits.

The researcher concluded that lumbar sympathetic nerve blocks had no significant clinical effect on treatment outcome for chronic low back pain, but such treatment did significantly increase the cost of treatment.

Editor's note:
This study is on a small number of patients, and reports presented at professional meetings have not necessarily been officially peer-reviewed for publication in the medical literature. Nevertheless, this is the kind of research (ie, comparing the outcome of one group of patients who are similar to another group of patients in all ways, including treatments, except that one group receives a certain additional treatment, in this case sympathetic nerve blocks, and the other group does not) that has been sorely lacking for most interventional pain treatments. Given the enormity of the public health problem of low back pain (documented in the audit by AdvancePCS mentioned above), this is the kind of research that demands replication by funding of much larger controlled studies.
RM Gallagher, MD, MPH

Parents' Perception of Children's Pain Varies According to Gender

Finnish researchers conducted a study of gender differences in parents' perceptions of children's pain to determine how gender affects perception of pain. The researchers examined 201 mothers' and 114 fathers' perception of pain in their children underwent a minor surgery. The boys and girls were ages 1 to 6 years old. The results indicate that fathers, more often than mothers, stated that their child was capable of pretending to have pain, that their child should learn to tolerate pain, and that pain is a normal part of a child's life. Furthermore, boys were expected to tolerate pain more than girls and parents may not give their children the pain medication prescribed.