Case 1.—A girl, 5 years of age, was brought to the Mayo Clinic because she limped. She had had no trouble with her extremities until she was 4½ years old. Then, without apparent cause, a transitory swelling with redness appeared on the dorsum of the right foot. This was said to have lasted only twelve hours One month after the appearance of these signs of inflammation, the child began to limp. She was taken to a physician, who made an examination without finding any explanation of the limp. The parents were reassured. The limp persisted, however, and the child was brought for further examination
On examination, the inner side of the dorsum of the right foot was tender. There was no redness, swelling or local heat. The Pirquet reaction was definitely positive. The examination of the chest, both clinical and roentgenologic, revealed negative results. The leukocyte count was 8,000. The