[Footnote 18: _Trans._, xxxiv., 1883, pp. 203-208.]
PROGNOSIS.--The course and the prognosis of rachitis are, as a rule, favorable, but they change according to the degree and locality of the affection and the age of the patient. Generally there is neither fever nor rapid exhaustion. But the process lasts for months and even years. In favorable cases, when recovery takes place the teeth will grow faster, the bones become firmer, the epiphyses will diminish in relative size, the bowels become regular. But the length of the bones is, and remains, reduced, and the head remains large as compared with the length of the body. Not only are the bones of normal firmness, but the compact substance undergoes a process of hardening called eburnation by Guérin. The internal organs also become very active, perhaps because the total amount of blood has to supply only a body less extended in length. Nor does the brain suffer after complete recovery has taken place. On the contrary, it appears that the somewhat more than normal vascular dilatation, which under unfavorable circumstances leads to effusion, is { 158} frequently apt to nourish the organ of intellect up to a higher standard. In all cases of rachitis, however, the curvatures of the extremities will not disappear altogether, while mild ones, it is true, are hardly recognizable in advanced age. Curvature of the ribs and of the vertebral column, however, will remain, and interfere with the expansion and the normal functions of the lungs and heart. In regard to the lungs, it appears that in many cases they do not find sufficient space to expand. As far as the heart is concerned, it touches the flattened, no longer elliptic, chest-wall over a larger surface, and is very apt to give rise to the suspicion of enlargement in consequence of extended dulness on percussion. The rachitic pelvis is well known to the obstetrician for the difficulties it gives rise to during parturition.
Thus, the prognosis would, as a general thing, be sufficiently favorable if it were not for the number of complications or severe symptoms. The chronic catarrh of the lungs accompanying rachitis, the enlargement of the tracheal and bronchial glands and the lymphatic glands in general, are apt to lead to inflammatory disease of the lungs, which, after having returned several times, leads to infiltration of the lungs with caseous deposits, and not infrequently results in phthisis. The nervous symptoms accompanying craniotabes may prove very dangerous. Spasm of the larynx and laryngismus stridulus may prove fatal in a single attack by suffocation, or general convulsion may set in during an attack of laryngismus or without it, in which the child may perish. Therefore the prognosis in every case of laryngismus and in every case of craniotabes has to be very guarded. It is my rule to wait from six to eight weeks before giving expression to a decided prognosis, because during that time medicinal and dietetic treatment will probably have resulted in such an improvement of the symptoms and condition as to render the prognosis more favorable. Under no circumstances, however, ought we to lose sight of the fact that, though rachitis may disappear, the causes leading to it may still linger on. Defective nutrition, diseases of the lungs, and intestinal affections which gave rise to or accompanied rachitis will complicate the prognosis, though rachitis itself, as far as the bones were concerned, be no longer in existence.