Acute periostitis frequently occurs in children in close proximity either to one joint, or less frequently to more than one, and may readily be confounded with acute articular rheumatism. But the constitutional disturbance in acute periostitis is prompt and severe at the outset; the swelling increases rapidly, is firmer than that of arthritis, does not involve the joint proper and its capsule, but, like the tenderness on pressure, exists above or below the articulations, especially around the head of the bone; there are no visceral complications, provided pyæmia has not supervened; the constitutional symptoms early assume a typhoid character, and unless an early incision be made a fatal issue soon ensues. The enlarged ends of the long bones and the pains in the limbs of rickets might lead to a suspicion of acute articular rheumatism, but the early age of such children, the absence of pain and swelling in the joints, the beaded condition of the sternal ends of the ribs, the late dentition and locomotion, the peculiarly shaped head, and other evidences of that affection, would prevent a careful observer from making a mistake. Inherited syphilis in infants, like rickets, may produce fusiform swelling and thickening at the ends of the long bones, especially the humerus and femur, and sometimes pain in the joints on movement; but at first the swelling {49} is confined to the epiphyseal line, and only later extends to the joint; there is a pseudo-paralysis of the limb, and but little pain or fever; bony osteophytes may often be felt under the skin at the line of union of the epiphysis with the shaft; the epiphysis often becomes separated from the shaft, and suppuration may ensue around the bone and in the articulation; sometimes adhesions and perforation of the integument take place, allowing of the escape of disintegrating osseous and cartilaginous tissue; and there will coexist either on the skin or mucous membrane some of the ordinary evidences of inherited syphilis.[120] The acute and subacute articular inflammations occasionally observed in cerebral softening and hemorrhage, in injuries and inflammation of the spinal cord and caries of the vertebræ, may be distinguished from acute and subacute articular rheumatism by the following circumstances: the existence of some one of these diseases of the brain or cord, the articular affection being usually confined to the paralyzed limbs; its invasion about the time of the setting in of the late rigidity, or even still later; the absence of cardiac complications and the presence of other trophic or neuro-paralytic lesions, such as acute sloughings, rapid atrophy of the palsied muscles, cystitis, ammoniacal urine, etc.[121] [Footnote 120: Vide Parrot, _Archives de Physiol. Norm. et Path._, 1872 and 1876; R. W. Taylor, _Bone Syphilis in Children_, New York, 1875.]