Clinical Experience of Risankizumab in Patients With a History of Erythrodermic Psoriasis

Erythrodermic psoriasis (EP) is a severe and challenging variant of psoriasis that often shows poor drug survival. While risankizumab, an IL-23 inhibitor, has demonstrated efficacy in patients with moderate-to-severe plaque psoriasis, its effectiveness in patients with a history of EP is less explored. This study aimed to evaluate treatment response to risankizumab and identify potential predictors influencing the treatment response. In this single-center, longitudinal retrospective study, we included 56 patients treated with risankizumab between August 1, 2016, and June 1, 2023, of whom 22 had a history of EP. Treatment response was assessed using the Psoriasis Area and Severity Index (PASI), and the impact of patient characteristics, including prior biologic exposure and HLA-Cw genotypes, on treatment response was analysed using the Mann–Whitney U test. Throughout the 100-week follow-up, patients with a history of EP exhibited a poorer treatment response compared to those without such a history. Among patients with a history of EP, those with prior exposure to guselkumab and those treated with more than five biologics demonstrated a decreased response to risankizumab. Additionally, there was a non-significant trend indicating that HLA-Cw1–negative patients responded better to risankizumab. This case series indicated that risankizumab might be an effective and sustainable treatment option for most patients with a history of EP. However, prior exposure to multiple biologics, particularly those with a similar mode of action targeting IL-23, may reduce its effectiveness. The potential association between HLA-Cw1 genotype and treatment response warrants further investigation.