Abstract
BACKGROUND: Little is known about treatment survival in patients with plaque psoriasis who have received phototherapy. OBJECTIVES: to analyse treatment survival in patients with plaque psoriasis who had received photother-apy, irrespective of the number of sessions and type of phototherapy, and to identify factors that influence the risk of treatment discontinuation. METHODS: Data from the Psoriasis Registry Austria and the phototherapy registry of the Centre of Phototherapy at the Department of Dermatology and Venereology, Medical University of Graz, were retrospectively analysed using Kaplan-Meier curves (logrank test) and a Cox (proportional hazards) regression analysis, irrespective of the number of phototherapy sessions or type of phototherapy. RESULTS: The analysis revealed an overall treatment survival rate of 70% and 66% after 1 and 3 years, respectively, with a median treatment survival of 5.5 years. However, treatment survival rates have significantly decreased compared with the rates reported in the prebiologic era [hazard ratio (HR) 1.98, P < 0.001]. While female sex did not influence overall treatment survival (HR 0.87, P = 0.28), the risk of treatment discontinuation was significantly lower in women aged ≥ 60 years (HR 0.49, P = 0.009). Moreover, patients with arthritis had an increased risk of treatment discontinuation (HR 1.69, P = 0.003). The involvement of high-impact body areas (including scalp, nail, or inverse and/or genital body areas) did not alter treatment survival; however, palmar and/or plantar involvement increased the risk of treatment discontinuation (HR 1.48, P = 0.006), especially in men (HR 2.19, P < 0.001). No significant differences in the treatment survival of phototherapy in patients were observed regarding the duration of the psoriasis. CONCLUSION: Male patients with psoriasis with palmar and/or plantar involvement have the highest risk of treatment discontinuation, whereas women aged ≥ 60 years at treatment start have the lowest risk. Therefore, early treatment escalation should be considered in men with palmar and/or plantar involvement and treatment-resistance disease forms. However, the current treatment survival rates reported for patients with psoriasis treated with phototherapy (median survival 30 months) are similar to the treatment survival rates reported for patients receiving tumour necrosis factor inhibitors.