Researchers in the Netherlands examined 289 rheumatoid arthritis patients being treated with TNF-alpha blocking drugs for one to 10 years. The drugs taken included two anti-TNF alpha antibodies, infliximab and adalimumab, and TNF-alpha receptors, etanercept and lenercept.

Results show 25 percent of patients taking TNF-alpha blocking drugs developed skin conditions such as infections, eczema and drug eruptions. Drug eruptions occurred mainly at the start of drug therapy. Also, 12 patients developed skin tumors and nine developed an ulcer.

According to the study, more than a quarter of the patients who developed skin problems stopped taking the TNF-alpha blocking drugs. In a control group of patients not on TNF-alpha blocking drugs and who had less severe rheumatoid arthritis, 13 percent complained of skin problems.

Skin problems such as skin infections are common in rheumatoid arthritis patients, say researchers, but TNF-alpha blocking drugs can increase this susceptibility because TNF-alpha plays a key role in the immune response to infections. Eczema however, also caused by this class of drugs, is not common in rheumatoid arthritis patients

Authors conclude, "Dermatological problems are a significant and clinically important problem in [rheumatoid arthritis] patients receiving TNF-alpha blocking therapy."