Poster Session : PS 0694 ; Rheumatology ; Appearance of Psoriasis after TNF-a Blocker and Use of Ustekinumab or Tocilizumab for Refractory Monoarthritis

Nowadays, tumor necrosis factor-a (TNF-a) blockers are used for the treatment of RA, infi ammatory bowel diseases (IBD), ankylosing spondylitis (AS), psoriatic arthritis (PsA), and psoriasis. Paradoxically, there are some reports of appearance of psoriasis after TNF-a blockers. We report a patient who have seronegative mono-rheumatoid arthritis (mono-RA) on knee joint that experienced psoriasis after TNF-a blocker therapy (adalimumab and etanercept). For the patient, oral medication is not available due to intolerance; thus, we tried ustekinumab which is an anti-IL-12/23 monoclonal antibody that has been used to treat psoriasis. After ustekinumab injection, psoriatic skin lesions and joint symptoms were much improved in the patient. But in the following period, joint pain and swelling aggravated and synovial fi uid cytokine levels such as IL-6 and IL-17 were elevated. Treatment was changed to tocilizumab, humanized monoclonal antibody against IL-6 receptor. After injection, knee joint swelling rapidly subsided without worsening of psoriatic skin lesion.