Scrofula, like other complaints, has been said to have been communicated by vaccination ; but that the disease possesses any specific morbid matter which is capable of being conveyed from one child to another by inocula tion is a doctrine which has now been proved to be destitute of any foun dation.
Morbid Anatol?? y.—The structural lesions induced by the scrofulous diathesis consist in various chronic inflammations with'their consequences. These have nothing special in their anatomical characters to distinguish them from the same lesions occurring in non-scrofulous children. They need not, therefore, be further referred to in this place.
The affection of the lymphatic glands, which is so characteristic a part of the disease, differs from the ordinary hyperplasia induced in a healthy child by neighbouring inflammation in the fact that the swelling does not subside when the irritant which has given rise to it has passed away, but continues as a chronic condition. In the case of a healthy child the gland becomes more vascular, and swells up by an increase in its corpuscular elements.
These rapidly increase, multiply, and enlarge, and acquire many nuclei which fill their interior. This is the first step. In the second, one of two things may take place. If the irritation subsides and cell-production is checked bef ire the nutrition of the gland is interfered with, a fatty degen eration takes place in the new cells which reduces them to a milky fluid. They are then absorbed and the gland resumes its former size. If, on the contrary, the irritation persist, the proliferation of cells continues ; they crowd together, destroying the reticulum and the capillary network of the gland, arrest nutrition by their pressure, and lead to rapid disintegration and suppuration. This, then, is an active process conducted rapidly. In the scrofulous child the course is much more protracted. The glands are apt to take on a chronic inflammatory process. They increase slowly in size, and remain a long time as indolent lumps, apparently incapable of fur ther change ; or, if the swelling have been originally acute, no diminution in size takes place when the inflammatory process is at an end. In either
case the gland is filled with proliferating cells, which by their pressure hinder nutrition, and induce an imperfect fatty degeneration, so that the gland is converted either wholly or in part into a mass of cheesy matter.
Glands so affected have a spongy feel, unless there is much hypertrophy of the connective tissue, in which case they become hard. Their section is pale red, passing into a dirty white or yellowish colour. After a time the whole gland becomes thick, tough, anmilic-looking, and dry, and is then quickly converted into an opaque, yellow, caseous mass. Disease in the glands is unequally distributed. Some are unaltered, and even of those affected there is great variety in the degree to which the process extends, for some remain small while others enlarge considerably. After remaining for a long time inactive one of two changes may take place. Either the gland softens, sets up inflammation around, and evacuates its contents ;. or the fluid part of the gland is absorbed, and the gland dwindles into a fibrous mass, or is hardened by the deposition of earthy salts. The cervi cal glands often suppurate ; the bronchial glands occasionally do so, but in the mesenteric glands such a termination is very rare.
Softening and suppuration constitute a chief danger of caseous glands. In the glands of the neck this is of less moment than in those of the closed cavities, for their contents are discharged externally, and are thus removed from the body. Even in these cases secondary consequences may ensue. The existence of a chronic discharging sore, such as often results from the suppuration of these glands, is very apt to induce arnyloid degeneration of the liver, kidney, and spleen. Therefore these organs are frequently diseased in scrofulous children. Besides, there is always danger that soften ing cheesy matter may give rise to an explosion of acute tuberculosis ; and many scrofulous children fall victims to this fatal disorder. In the case of the bronchial and mesenteric glands softening and suppuration are still more serious, on account of the effect upon neighbouring organs. This subject will be referred to afterwards.