Notes on a rare case of essential osteolysis.

In 1944 a schoolboy, then aged thirteen, was wounded slightly in the right foot by a nail, which caused a moderate lymphangitis of the leg. A month before, while running, he had felt his right leg give way momentarily. A few days after the injury to his foot, while he was bathing in the sea and already recovered from the trauma, he suffered a sudden pain in the right groin which increased rapidly and became very severe a few hours later. There was marked pyrexia, with rigors, and examination showed a diffuse tender swelling of the right thigh and limitation of hip movements. Under sulphonamide treatment the fever and pain subsided and full hip movement was regained within a week. However, from that time, whenever the patient walked his leg would become affected with oedema of the thigh and knee, which would disappear with rest. A few days later the same clinical picture of pyrexia preceded by rigors recurred; hip and knee movements were greatly impaired, and there was lymphadenitis in the groin. Sulphonamide treatment was resumed and the patient felt well after three days, with disappearance of the