New onset or exacerbation of psoriatic skin lesions in patients with definite rheumatoid arthritis receiving tumour necrosis factor α antagonists

Background: Blockage of tumour necrosis factor alpha (TNF alpha) is highly effective in rheumatic diseases, especially in rheumatoid arthritis (RA), ankylosing spondylitis, and psoriatic arthritis. Furthermore, TNF alpha antagonists have also been shown to significantly reduce psoriatic skin lesions. Case reports: A series of nine patients with RA who were treated with different types of TNF alpha antagonists and who unexpectedly developed either a new onset or an exacerbation of psoriatic skin lesions are reported.