Successful treatment with deucravacitinib following secondary failure of risankizumab in a patient with severe plaque psoriasis

We report a case of severe plaque psoriasis in a 49-year-old woman with schizophrenia and depression, who had suffered from widespread pruritic psoriatic plaques for over 20 years.The patient had a habitual tendency to rub and scratch the lesions, which aggravated the disease.She initially showed a complete response (Psoriasis Area and Severity Index, PASI 0) to risankizumab, an IL-23p19 monoclonal antibody.However, three years later, she experienced secondary failure characterized by rapid lesion recurrence and severe pruritus.As the underlying cause of treatment failure was unclear, therapy was switched to deucravacitinib, a selective oral TYK2 inhibitor.Within two months, the patient exhibited significant clinical improvement, with near-complete clearance of plaques and relief of pruritus.This case highlights the potential of TYK2 inhibition as an effective alternative in patients who experience secondary loss of efficacy with IL-23 inhibitors.