Erythrodermic psoriasis with early diagnostic uncertainty requiring multidisciplinary rheumatological management: A case report.

Erythrodermic psoriasis is a rare and potentially life-threatening variant of psoriasis characterized by diffuse erythema and scaling involving the majority of body surface area. The clinical presentation may overlap with severe cutaneous adverse reactions, such as Stevens-Johnson syndrome and toxic epidermal necrolysis (TEN), creating diagnostic uncertainty and therapeutic challenges. Standard treatment includes cyclosporine or biological therapy, whereas intravenous immunoglobulin (IVIG) is traditionally reserved for TEN. The present case report describes the case of a 42-year-old woman with biopsy-proven psoriasis and polycythemia vera who presented with rapidly progressive erythroderma involving ~90% of her body surface area following cyclosporine dose escalation. Marked systemic inflammation and TEN-like features prompted treatment with IVIG at 400 mg/kg/day for 5 consecutive days, resulting in a marked clinical improvement. She was subsequently transitioned to secukinumab for maintenance therapy. The present case report highlights IVIG as a potential rescue therapy in severe erythrodermic psoriasis when diagnostic overlap with TEN exists and rapid disease control is required.