DUDLEY, UK—Cutaneous abnormalities are more common in patients with rheumatoid arthritis (RA) than in those with noninflammatory rheumatic problems, and RA patients often blame their skin problems on RA treatment drugs. George D. Kitas, MD, PhD, FRCP, and colleagues from the Department of Rheumatology at Dudley Group of Hospitals NHS Trust in the West Midlands, UK, checked this with dermatology consults and found that, apart from steroid-related bruising, the drugs were rarely to blame. The investigators did find that athlete's foot is more common in RA patients. The study is published in the October issue of Annals of the Rheumatic Diseases.¹

"Skin rashes are common in RA patients and may be completely independent of the disease or relate to the disease itself or its treatment." Dr. Kitas told CIAOMed. "Deciding what the problem is and what it is due to is important for the continuing management of these patients. Discontinuation of effective drugs on the suspicion that they are causing skin problems should only be carried out after very careful consideration and, if possible, an assessment by a dermatologist."

The observational study of 205 RA patients and 144 patients at the same clinic with noninflammatory rheumatic conditions (primarily osteoarthritis) that both self-reported and clinically verified skin abnormalities were more common in the RA (61% vs. 47%, P <.05, and 76% vs 60%, P <.05, respectively. In particular, bruising, athlete's foot, scars, rheumatoid nodules and vasculitic lesions were more common in RA patients.

The researchers conclude that skin abnormalities associated with RA should not be ignored. "Dermatological disease affects the perception of a patient's body, and when it occurs in people who are already experiencing changes in body image because of their RA, it may put additional strain on their coping mechanisms," the team reports, calling for greater attention to skin problems and better education to help patients cope.

Rheumatoid nodules were present in 19% of RA patients and in none of the controls. Interestingly, the researchers note that many RA patients do not think of these as skin problems and so did not report them. Those with nodules were more likely to be taking methotrexate: but it was unclear whether the nodules were the result of the treatment "or simply reflected the fact that rheumatoid nodules are a confounder for aggressive disease, for which the preferred treatment is methotrexate." 

Nail signs, including ridging and onycholysis, as well as skin atrophy, were more common in RA patients, but the study was too small to support strong conclusions about these conditions.

Athlete's foot, not previously seen as being related to RA, was found to be 'considerably' more common in RA patients than in controls (7.3% vs 2.1%, P <.05). The investigators suggest that this may be related to immunosuppressant therapy or to the fact that RA patients "may be sufficiently disabled to prevent adequate foot hygiene, particularly in deformed feet with over-riding toes."  This latter problem could be serious, the researchers warn, as skin breaks due to fungal infection may "act as a point of entry for infection and thus predispose patients to cellulites or more sinister effects".

None of the patients in this study were taking TNF inhibitors or other biologicals, and Dr. Kitas said similar studies in larger cohorts of patients would allow a more accurate identification of predictors of skin problems in patients with RA. "Longitudinal, long-term observational studies may be able to address the effects of specific therapies, for example the anti-TNFs," he told CIAOMed.

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Reference

1. Douglas KMJ, Ladoyanni E, Treharne GJ et al.  Cutaneous abnormalities in rheumatoid arthritis compared with non-inflammatory rheumatic conditions. Ann Rheum Dis. 2006;65:1341-1345.