Effect of psoriatic arthritis on treatment response in patients with moderate to severe psoriasis

Background: Among patients with moderate-to-severe psoriasis, efficacy, and tolerability of available treatments based on psoriatic arthritis (PsA) history are not well-described. Objective: We evaluate disease characteristics and treatment response variation in the moderate-tosevere psoriasis population based on PsA history. Methods: Simple-measure for assessing psoriasis activity (S-MAPA) was used to retrospectively analyze treatment responses. Results: 191 moderate-to-severe psoriatic patients, 58 with and 133 without rheumatologist-diagnosed PsA were analyzed. Regardless of PsA history, S-MAPA improvement was similar with biologic monotherapy (46.2 versus 44.1; P=0.74), traditional systemic monotherapy (62.29 versus 38.12; P=0.22), and combination treatments (64.62 versus 52.71; P=0.40) after 12 weeks. PsA patients on biologic monotherapy experienced a higher infection rate than patients without PsA (0.57% versus 0.19%; P=0.01). PsA patients experienced more adverse events (AEs) associated with traditional systemic monotherapy than biologic monotherapy (3.25 versus 1.04; P=.001). Limitations: The relatively small PsA cohort was the primary limitation. Conclusions: Patients with moderate-to-severe psoriasis responded similarly to all treatments independent of PsA history. PsA patients received more overall treatments and more biologic monotherapy prescriptions. PsA patients had a greater infection risk on biologic monotherapy compared to those without PsA, and greater adverse events risk on traditional systemic monotherapy compared to biologic monotherapy.