Complex presentation of probable catastrophic antiphospholipid syndrome: diagnostic dilemmas and treatment strategies.

Catastrophic antiphospholipid syndrome (CAPS) is a rare and life-threatening clinical emergency with multiorgan involvement. CAPS presents a significant clinical challenge due to its heterogeneous presentation and can resemble many other systemic thrombotic disorders. Prompt and intensive treatment is essential for patient survival. However, due to its rarity and heterogeneity, evidence-based protocols are scarce, and as such, diagnosis and management rely on guidelines stemming from low-level evidence and expert opinion. We present a patient with antiphospholipid syndrome who developed multiorgan complications and was diagnosed with probable CAPS. Diagnosis was complicated due to thrombotic risk and the heterogeneous nature of CAPS, as well as his unresponsiveness to first-line therapy consisting of anticoagulation and corticosteroids. His treatment was then escalated with plasma exchange, rituximab and cyclophosphamide, to which he responded and improved clinically.