To investigate rates and risk factors for incident and recurrent psoriasis in rheumatoid arthritis (RA) patients treated with different biologic (b) and conventional synthetic (cs) disease-modifying antirheumatic drugs (DMARDs).
RA patients enrolled in the German biologics register RABBIT without (n = 14,525) or with a history of psoriasis (n = 375) were analyzed separately. All first events of psoriasis reported until October 2017 were assigned to the treatments prescribed in the previous 3 months. Crude incidence rates (IR) of psoriasis were calculated per 1000 patient-years. To investigate risk factors for psoriasis, cox regressions with and without inverse probability weights were applied to adjust for confounding by indication.
117 incident and 37 recurrent psoriatic events were reported. Patients exposed to TNFi had a significantly higher incidence rate (IR = 3.04/1,000 PY) than those exposed to csDMARDs only (IR = 0.65), whereas IRs for abatacept, rituximab and tocilizumab did not differ significantly from csDMARDs. Adjusted Cox regression confirmed a higher risk for TNFi. Female sex (HR: 1.7) and smoking (HR: 2.1) were significantly associated with incident psoriasis while methotrexate decreased the risk (HR: 0.5). For recurrent psoriasis, IRs for TNFi, abatacept and rituximab were significantly higher than for csDMARDs.
Our data confirm a previously observed increased risk of incident psoriasis in patients exposed to TNFi compared to csDMARDs. However, the overall risk is low and the event is usually non-serious. Comedication of TNFi with methotrexate seems to lower the risk of incident psoriasis. In patients with a history of psoriasis, recurrence as adverse event is rare.