Rachitis

(ra-ki'-tis). I. Rickets, the " English disease" a constitutional disease of infancy, characterized by impaired nutrition and changes in the bones. Rachitis was first accurately described by Gli on, in the seven teeth century, The' disease comes on insidiously at about the period of dentition, and three general symptoms are usually present— a diffuse sorene of the body, slight fever, and profuse sweating about the head and neck. Coincident with these the skeletal lesions appear, the chief of which are the bending of the ribs, the arching of the long bones, with thickening at the junction of the shaft and the epiphysis, and the development of hyperostoses on the frontal and parietal eminences, producing the caput quadratum. Dentition is delayed, nervous symptoms are marked, as peevishne and sleeple ne , and in some cases convulsions and laryngismus stridulus; and all the manifestations are accompanied by a state of general weakne . The cartilage between the shaft and the epiphysis of the long bones is greatly thickened, the line of o ification is irregular and more spongy and vascular than normal, and beneath the periosteum, which strips off easily, there is spongioid ti ue resembling decalcified bone. Chemic analysis shows a marked diminution in the lime-salts. Ka owitz regards the hyperemia of the bone, the marrow, the cartilage, and the periosteum as the primary lesion, on which all the others depend. 2. In biology, a disease causing abortion of the fruit or seed. R. adultorum, osteomalacia; mollities o ium. R. annular is, congenital rachitis characterized by the production, after birth, of furrows of the bones and fractures (Winckler). R. micro melic a, intrauterine rachitis, characterized by shortening of the limbs and thickening of the diaphyses (Winckler). R. senilis. See R. adultorum.