Fatal allergic vasculitis associated with celecoxib.

We report on the occurrence of a rare and as yet unforseeable adverse reaction to treatment with celecoxib, a cyclooxygenase-2 (COX-2) selective, non-steroidal, anti-inflammatory drug. A previously healthy adult suffered fatal acute multiple organ failure presumably after diffuse allergic vasculitis with diffuse necrotic purpura. Although no conclusive proof is available, such a reaction could have been triggered by at least one of two mechanisms: an allergic reaction linked to the chemical structure of celecoxib; or an interaction of the drug with synthesis of endothelial eiconasoids leading to an imbalance between vasoactive end products, resulting in widespread rise to local thrombosis.