Background: Few systematic data on sex-related treatment responses exist for psoriasis.

Objectives: To evaluate sex differences with respect to systemic antipsoriatic treatment.

Methods: Data from patients with moderate-to-severe psoriasis in the PsoBest or Swiss Dermatology Network of Targeted Therapies (SDNTT) registries were analysed. Treatment response was defined as achieving a ≥ 75% reduction in Psoriasis Area and Severity Index (PASI 75) or PASI ≤ 3 at treatment months 3, 6 and 12, supplemented by patient-reported outcomes [i.e. Dermatology Life Quality Index (DLQI) ≤ 1 and delta DLQI ≥ 4].

Results: In total, 5346 patients registered between 2007 and 2016 were included (PsoBest, n = 4896; SDNTT, n = 450). The majority received nonbiological treatment (67·3% male, 69·8% female). Women showed slightly higher PASI response rates after 3 (54·8% vs. 47·2%; P ≤ 0·001), 6 (70·8% vs. 63·8%; P ≤ 0·001) and 12 months (72·3% vs. 66·1%; P ≤ 0·004). A significantly higher proportion of women achieved a reduction in DLQI ≥ 4 [month 3: 61·4% vs 54·8% (P ≤ 0·001); month 6: 69·6% vs. 62·4% (P ≤ 0·001); month 12: 70·7% vs. 64·4% (P ≤ 0·002)]. Regarding PASI ≤ 3, women on biologics showed a significantly superior treatment response compared with men at 3 (57·8% vs. 48·5%; P ≤ 0·004) and 6 months (69·2% vs. 60·9%; P ≤ 0·018). Women in the nonbiological treatment group had a significantly better treatment response (PASI response, PASI 75 and PASI ≤ 3) over 12 months compared with men.

Conclusions: We provide evidence that women experience better treatment outcomes with systemic antipsoriatic therapy than men.