“…In contrast, reports on arthritis induced or exacerbated by these agents are rare. Among a total of 988 Spanish patients with psoriasis treated with biologics, new‐onset PsA was observed in 5·8%, 0·55% and 0·45% of patients treated with efalizumab, infliximab and etanercept, respectively, while none of the patients on adalimumab developed arthritis . Three of 107 patients with rheumatoid arthritis receiving infliximab experienced exacerbation 3 months to 1 year after its initiation, and a dose increase resulted in deterioration .…”