Acute erythrodermic psoriasis complicated by systemic capillary leak syndrome following secukinumab therapy: a case report.

A 66-year-old woman with a 6-month history of new-onset psoriasis after her first dose of COVID-19 vaccination recently progressed to acute erythroderma accompanied by fever and systemic inflammation. She was started on secukinumab for erythrodermic psoriasis (EP) after conventional therapies were contraindicated. On hospital day 6, her condition deteriorated with dyspnea, high fever, and edema. Laboratory evaluation revealed severe hypoalbuminemia and elevated inflammatory cytokines, with no evidence of infection. Imaging studies showed pulmonary edema and massive pleural effusions requiring therapeutic thoracentesis. After excluding sepsis, cardiogenic pulmonary edema, and allergic reactions, a diagnosis of systemic capillary leak syndrome (SCLS) complicating EP was established. Secukinumab was discontinued, and the patient received supportive care while being switched to apremilast. Her condition improved rapidly, with resolution of fever, reduction in pleural effusions, and significant diminishment of skin erythema. This case highlights a rare but life-threatening complication of severe acute EP, as both conditions are driven by a systemic cytokine storm. A single loading dose of secukinumab failed to effectively control the systemic cytokine storm in this patient, and the potential association between secukinumab administration and disease progression requires further investigation. We review the pathogenesis of EP, differentiate it from plaque psoriasis, identify the risk factors for SCLS, and discuss therapeutic considerations. Clinicians managing patients with severe psoriasis should remain vigilant for the potential occurrence of SCLS, particularly in those presenting with acute EP. Additionally, careful consideration should be given to the selection of biologic agents in high-risk patients.