PTGS2 and blood coagulation disease: Our patient reported no trauma, renal disease or coagulation disorder but had a history of ankylosing spondylitis for which he had received various courses of methylprednisolone and non-steroidal anti-inflammatory agents (NSAIDs) in the past; at the time of presentation our patient was on nimesulide, a selective cyclooxygenase-2 (COX-2) inhibitor.