PHILADELPHIA PEDIATRIC SOCIETY

Abstract

long bones in three cases of chronic lead poisoning. We do not know as yet whether the shadow is cast by the metal in the newly formed trabeculae (in the way in which Aub and his collaborators think occurs in lead poisoning), or whether, as in the case of phosphorus, the formation of trabeculae has been brought about by the lead, and the shadow is caused by a more dense formation of bone. Perhaps other heavy metals will produce intensification of shadows at the growing ends of long bones. It is true that cupping occurs less commonly in congenital syphilis than in rickets. But the formation of spurs which prolong the line of the cortex at the ends of the bone is very common in that disease. Often a spur is present in the x-ray plate, at one or both sides of the end of a long bone, but the end of the bone continues to present a normal flat contour in contrast to the curved contour seen in advanced rickets. If time were not lacking, I should like to discuss the differential diagnosis between healing rickets and scurvy and congenital syphilis. It is often exceedingly difficult to be certain from the x-ray plate from which of these three diseases the infant suffers, and one is often forced to rely on knowledge other than that furnished by the x-ray plate to establish a diagnosis of congenital syphilis.