Rickets (according to Skeat, akin to A.S. wringan, 'to wring'), or RACHITIS (Dr Glisson's pseudo-Greek coinage in 1650 from Gr. rhachis, 'the spine,' because a peculiar form of spinal curvature results therefrom), is a disease of children, chiefly characterised by the imperfect development, softness, and consequent distortion of some or many of the bones. The bones thus affected consist of a sort of gelatinous tissue, which will bend without breaking; and they are so soft that they may be bent with the knife. Though so soft, they are thickened, especially at the parts where growth normally takes place most rapidly; the enlargement of the wrists, ankles, &c. which results has led to the term 'double-jointed,' often applied to those suffering from the disease. The weight of the body and the traction of the muscles acting on bones thus constructed cause them to bend, and the thighs or shins are abnormally arched, or the spine is curved, or, in slighter cases, only the normal form of the ankle is modified. In aggravated cases the chest is so affected as to give rise to the condition known as 'pigeon-breasted;' the lower jaw is imperfectly developed, and the teeth project; and the pelvis becomes so altered in form as, in the case of girls, to render future childbearing in the highest degree perilous. Rickets is exclusively a disease of childhood, and rarely begins later than the second year. It appears to be caused by unhealthy surroundings, particularly defective or improper food, and insufficient light and air. It is therefore much more common among the poorer classes, and in towns. It is not due in most cases to the want of lime-salts in the food, but to the want of power in the child's system to assimilate them. In some of the large cities of Europe one-third or even a larger proportion of the children brought to the out-patient departments of hospitals are more or less affected. It is a very chronic disease, and if at all severe leaves its mark on the bones for life. It is very rarely fatal of itself; but affected children are much less able than others to resist attacks of other diseases (bronchitis, diarrhoea, hooping-cough, measles, &c.). In Germany this malady is, under an old misapprehension, called the 'English disease.'
The treatment must be mainly directed to the improvement of the general health. Free exposure to pure bracing air, sponging with sea-water, or sea-bathing if the little patient can bear it, an abundance of suitable and nourishing food, cod-liver oil, iron, and quinia include all that need be said about general treatment. The administration of lime-salts seems to do little good, though it might naturally be thought the one thing needful. While the bones are still soft great care must be taken to keep the child in such attitudes as will cause the least possible strain upon the affected parts. When the bones have become ossified in faulty positions surgical interference may often be useful in producing amelioration of the condition.