WASHINGTON – Ulcers of the lower leg and foot occurred at an incidence of 1% per year among people with rheumatoid arthritis, with the rate having doubled over the last few years, according to findings from a retrospective assessment of a population-based incidence cohort in Olmstead County, Minn.
Eric L. Matteson
The study cohort all met the 1987 American College of Rheumatology criteria for rheumatoid arthritis (RA) in 1980-2007. The cohort included 813 people with RA, said Dr. Adlene Jebakumar during her presentation at the annual meeting of the American College of Rheumatology. Of these, 66% were positive for rheumatoid factor, 53% had erosive joint disease, and 33% had rheumatoid nodules, all markers of severe disease.
During 9,771 total person-years of follow-up, there were 171 episodes of leg and/or foot ulcers in 125 of these people. These cases did not include ulcers resulting from animal bites, surgery, burns, biopsy, cellulitis, ingrown toenails, toenail removal, abrasion, foreign body, or herpes zoster.
Patients’ mean age at first ulcer onset was 73.5 years, and 74% were female.
The area between the ankle and knee was the most common location for ulcers (58 ulcers, 34%), followed by the tips of the toes (46 ulcers, 27%).
The major etiology was pressure (62 ulcers, 36%) or trauma (49 ulcers, 27%). Another 22 ulcers (13%) were ischemic, and 2 (1%) were vasculitic, reported Dr. Jebakumar of the division of rheumatology at the Mayo Clinic in Rochester, Minn.
The incidence of lower leg and foot ulcers was higher among patients diagnosed with RA in 1995-2007, compared with those diagnosed in 1980-1994 (hazard ratio, 2.03; P less than .001). The median time for the lower leg and foot ulcers to heal was 30 days. Ten (6%) of 171 episodes led to amputation. Lower leg and foot ulcers in RA were associated with increased mortality (HR, 2.42; P less than .001), adjusted for age, sex, and calendar year.
The risk factors for lower extremity ulcers in RA were age (HR, 1.90/10-year increase; P less than .001); current smoking (HR, 1.51; P = .048); diabetes mellitus (HR, 1.65; P =.015); coronary heart disease or heart failure (HR, 1.56; P less than .035); presence of rheumatoid nodules (HR, 1.64; P = .010); ESR of 60 mm/hr or greater on three occasions (HR, 1.78; P = .022); venous thromboembolism (HR, 2.08; P = .014); and severe extra-articular manifestations (HR, 1.67; P = .048). The patients on corticosteroid therapy accounted for 79 (46%) of 171 ulcer episodes.
Dr. Eric L. Matteson said in an interview that the incidence of leg and foot ulcers in RA patients should not come as a surprise. "Leg ulcers are a real big problem in RA because these patients have increased cardiovascular disease and peripheral artery disease. Lots of ulcers are due to poor circulation. And long-term high-dose steroids sometimes used to treat RA patients may contribute to that."
The situation is made worse in elderly patients who become sedentary in response to lower-extremity RA-related pain, he added.
"The best prevention of lower extremity ulcers is to have RA under control," said Dr. Matteson, chair of the department of rheumatology at the Mayo Clinic. And treat ulcers early in their course, when they are small, he noted, adding that patients need to be told to seek care early rather than wait until the ulcers have become large and harder to heal.
Another important aspect of prevention is harder to do than it sounds: "Keep patients active," Dr. Matteson advised.
Dr. Jebakumar and Dr. Matteson reported having no relevant financial conflicts of interest