Popliteal Mycotic Aneurysm Presenting as Septic Arthritis and Purpura

A 44-year-old man, previously in excellent health, developed a mycotic aneurysm of his popliteal artery. Classic signs of arterial wall sepsis were preceded by septic arthritis in the great toe and knee joint on the affected side and diffuse purpura in the skin. The aneurysm was successfully resected and good arterial blood supply in the leg obtained by an autologous vein graft. We believe this is the first description of septic arthritis or purpura as presenting signs of a peripheral mycotic aneurysm.