Abstract: Erythrodermic psoriasis (EP) is characterized by intractable disease, a high recurrence rate and poor response to conventional therapies. Subcutaneous secukinumab represents an effective therapeutic option for EP, yet cases of exacerbated cutaneous lesions induced by this agent are rarely reported. Herein, we report a 79-year-old female patient with EP who failed to respond to acitretin and methotrexate. Progressive worsening of skin lesions and pruritus occurred following secukinumab administration, so the drug was discontinued and switched to oral upadacitinib. Marked relief of pruritus and darkening of lesions were observed 3 days after treatment initiation, and a 90% improvement in PASI score was achieved at week 4. This case suggests that JAK1 inhibitors may serve as an effective alternative for EP patients experiencing disease deterioration after treatment with IL-17 inhibitors.

Key words: erythrodermic psoriasis, upadacitinib, secukinumab, JAK1 inhibitors