be inflammatory by F. A. Walter.[2] Renard looked for that inflammation
in the periosteum. Guérin emphasizes the vascular increase in
periosteum, bone, and marrow; Trousseau and Lasègue the congestive
character of the local tumefaction, besides fever and pain. Virchow
also[3] inclines to the opinion that the rachitical process is of an
inflammatory nature, though it be impossible to state the exact cause
of the process. Still, he claims that we are no better off in regard to
other inflammations of unknown character--for instance, those of the
skin--and that we have to look for a future increase of our knowledge
of such constitutional predisposition of the organism and of such
specific qualities of the blood as will produce the local irritation of
the osseous tissue in rachitis. Last, and mainly, it is Kassowitz who
seeks the {138} essence of the rachitical process in a chronic
inflammation originating in the points of apposition of the growing
bones of the foetus or infant. During the chronic inflammation
blood-vessels are formed in large numbers, and a morbid congestion
takes place in all blood-vessels, but mainly in those of the localities
in which new bone is forming; thus in the chondro-epiphyses, in the
perichondrium and periosteum, and the sutural substances. Faulty
introduction or elimination of lime has nothing to do with this
process. It cannot be deposited in the current of a copious
circulation; in fact, it is not deposited in the immediate neighborhood
of blood-vessels to any extent. Even in otherwise normal bone hyperæmia
produced by the experimenter softens the bone, which was fully formed
before. If the relative percentage of lime were of any account in the
etiology of rachitis, the periosteal and cartilaginous proliferations
would find no explanation. But why is it that this peculiar process
takes place at an early age only? and in the bone only? Kassowitz urges
the fact that the growth of the bone differs in this from the
development of all other tissues: that the latter grow uniformly
through their whole mass; that the circulation in them is more uniform
and carries material through and into every particle simultaneously,
while in the bones the only places in which the whole circulation can
contribute to their growth--the few blood-vessels distributed in the
interior not adding to their growth at all--are the periosteum and the
places of apposition between epiphysis and diaphysis. Every morbid
irritation, whether resulting from bad air, habitation, and food, or
from either chronic or acute ailment, acts on the whole mass of other
tissues and organs, but in the bones only on the growing ends or
surface.
[Footnote 2: _Anatom. Museum_, Berlin, 1796, vol. ii.]
[Footnote 3: _Arch. f. Path. Anat._, vol. v.]
The results of the pathologists and experimenters are confirmed by
chemical analyses. Fat has been generally found somewhat increased in
the rachitical bones, and water largely so; chondrin is diminished
according to Marchand and Lehmann, but was found unaltered in the later
analyses of A. Baginsky. The latter found, after having deprived the
bone of fat, the organic and inorganic material to be in a proportion
of 100 to 563 in the normal, and of 100 to 160 in the rachitical
osseous tissue; and in 100 parts of dry bone, Gorup-Besanez found in
the
Ossein. Phosphoric Acid. Lime. Manganese Oxide.
Healthy adult 34 26 34 0.3
Infant of six months 34.9 27 35 0.5
Rachitical femur 72 7 9 0.3
" tibia 60 12.9 17 0.3
Defective calcification of the forming bone is one of the principal
characteristics of rachitis. In it lime cannot either enter into the
composition of the osseous tissue or remain in it. Its elimination must
take place either through the kidneys or the intestinal tract. In the
feces Ad. Baginsky, and many before him, have found an abnormal
quantity. In regard to the urine, modern investigations do not agree
with former analyses. Thus, Baginsky concludes that there is no
increase of lime in the urine of rachitical as compared with that of
healthy children; Seemann found even a diminution of the percentage of
lime. Amongst modern writers only Rehn found an occasional increase of
lime in the urine of rachitis.
{139} In regard to the elimination of phosphoric acid, the analyses of
different periods do not agree any better. The conclusions of previous
researches, pointing to a quadruple elimination of phosphoric acid in
the urine of rachitis, are refuted by Seemann, who found no increase,
and by Baginsky, according to whose researches the phosphoric acid of
the healthy urine compares with that of rachitical urine as 40:12-37.
As far as the elimination of nitrogen is concerned, there appears to be
but little difference between normal and rachitical urine. Chlorine was
found to be diminished in rachitis by Baginsky. Lehmann and Von Gorup
found lactic acid several times. Several times albumen was met with; in
a case of Ritchie's, blood; in one of Von Gorup's, fat.[4]
[Footnote 4: E. Salkowski und W. Leube, _Die Lehre vom Harn_, 1882, p.
536.]
The etiology of rachitis must be studied from two points of view. It
has its predisposition and its direct and proximate causes. The former
has been studied by F. W. Beneke[5] upon an anatomical basis. He finds
that the arteries of rachitical patients are large all through the
body. This is so particularly in the carotids; it seems probable that
the changes taking place in the head are due to this anomaly in the
size of the arteries. Three cases in which the width of the arteries of
the neck was unusually large terminated fatally--one by hydrocephalus,
one with a very large skull, and one suddenly. This width of the
arteries is most marked, under ordinary circumstances, from the second
to the fourth year; that is, the exact time in which (except the cases
of early rachitis) the rachitical process is at its height. It is
considered by Beneke to be the cause of the local increase of vascular
irritation, particularly in the epiphyses with their retarded
circulation; and also of the increase of nutritive development which is
so often noticed during recovery from rachitis; and, finally, of the
many pulmonary complications of an inflammatory nature.
[Footnote 5: _Die Anatomischen Grundlagen der Constitutions Anomalien
des Menschen_, 1878, p. 75, etc.]
There is another interesting consideration in regard to the effect of
wide arteries on the relations between the blood and tissues. A great
many more blood-cells are required to fill the arteries when wide than
when narrow. Now, the formation of blood-cells is hindered by any
disease of the digestive and blood-preparing organs, so that the
tissues are liable to show the relative increase in the percentage of
water, which is uniformly confirmed for rachitis by the biochemists.
The pulmonary artery of the healthy infant is larger than the aorta by
not more than four millimeters. In the majority of cases of rachitis
examined by Beneke this difference in size was very much more favorable
to the pulmonary artery; it is abnormally large in rachitis. This
anatomical fact is suggestive of the pathological processes so
frequently found in the lungs and in the neighboring lymphatic and
large abdominal glands. For, while the amount of blood introduced into
the lungs through its wide artery is unusually large, particularly so
in a chest which is contracted in consequence of the rachitical process
in the bones, the exit from the lungs is relatively impeded. Not only,
however, the narrowness of the chest is a cause of this disproportion.
For even in rather normal chests the lungs of rachitical children are
relatively small.
The liver of almost all rachitical children is large. In but one-half
{140} of the cases this enlargement is accompanied with a large heart.
In pure cases of scrofula, on the contrary, Beneke found a small heart,
rather narrow arteries, and usually a small liver, the size of the
lungs offering but few anomalies.
The spleen also is large in the majority of cases. Its size is not
dependent on the large size of the liver or the small size of the
lungs. For these conditions are found in the majority of cases only,
not in all of them, and the large spleen is not always found with a
large liver and small lungs. The variability of the anatomical
conditions permits of various degrees of combination; so that varying
combinations of rachitis with other constitutional disorders may
correspond with the different sizes of the principal organs. After all,
as there is a great deal of independence of these organs, as to size,
of each other, the conclusion is justified that those differences are
not the result of the disease, but that they are congenital and stand
in some causal relation with it.
The kidneys are large in the majority of cases, like the spleen and
liver, while the lungs are small. This disproportion is apt to result
in a hyperæmic condition of all the organs of the abdominal cavity, and
especially of the kidneys. To what extent this undue amount of volume
interferes with, or increases, renal secretion, it is difficult to say.
The amount of urine secreted by rachitical children is about normal,
though, as already stated, the percentage of lime in it is rather
diminished, contrary to the opinions held formerly.
For the direct cause of rachitis Glisson looked to the inequality of
nutrition by the arterial blood, and for that of the curvature of the
long bones to their superabundant vascularization. He found the disease
mainly amongst the well-to-do classes, not unlike a modern American
writer, who declares infantile paralysis to be the result of the
nervousness of the better classes of the American people! John Mayow
(1761) held a disturbance of the innervation responsible; Zeviani (in
the same year), improper food in general, and particularly prolonged
lactation; and Selle (1791), a peculiar diathesis (acrimonia
rachitica). About that time a defective nutrition with abnormal
function of the lymph-ducts was looked upon as the cause of rachitis by
many--by others, an undue production of acid, and the softening of the
osseous tissue thereby. This result was attributed by some to the
influence of milk (Veirac, De Krzowitz). Attention was directed at an
early time to phosphoric acid and lime, with the view that variations
in the elimination of these substances might explain the occurrence of
rachitis. A large quantity of both was found in some urines (Malfatti);
a superabundance of phosphoric acid was presumed to prevail in the
whole system (Wendt, Fourcroy); while symptoms resembling rachitis were
found in animals fed upon small doses of phosphoric acid by Caspari
(1824). Chossat fed young animals on food deprived of lime, and claimed
to produce softening of the bones and death, a result which was denied
by Friedleben. Guérin claimed to produce rachitis by feeding young
animals on meat in place of their mother's milk, a result equally
denied by Tripier, who, like Friedleben, found the bones under such
circumstances more liable to fractures, but not rachitical. Wildt and
Weiske found the bones uninfluenced by withholding lime from food;
Forster, however, and Roloff claimed to notice a marked influence, and
the latter {141} stated that animals, after having been rendered sick
by depriving them of lime, recovered when they were again supplied with
it. Wegner, in his numerous experiments with phosphorus, found that in
growing animals it increases the growth and firmness of both long and
flat bones; after the growth of the animal has been completed it
renders epiphyses and vertebræ denser. There is no change, however, in
the relative chemical composition of those parts. He found at the same
time that results similar to those caused by the administration of
phosphorus were obtained when food deprived of its phosphate of lime
was given. But he met with no rachitical changes proper during these
several procedures. Teissier having found an increase in the urine of
rachitis after the administration of lactic acid, and lactic acid
having been frequently found in the urine of rachitical patients by
Ragsky, Morehead, Simon, and Lehmann, C. Heitzmann fed with lactic acid
both carnivorous and herbivorous animals, found the cortical layer of
the bones softened and the medullary substance hyperæmic, and claimed
to produce rachitis in the former and osteomalacia in the latter. Both
of these assertions were denied by Tripier and Toussaint, who insist
upon Heitzmann's having selected animals which have a peculiar
disposition to suffer from rachitis. Again, Milne Edwards and
Boussaingault found the bones softened when they withdrew both
phosphoric acid and lime from the food, without restoring the bone's
consistency by administering powdered bone. But, lately, Ad. Baginsky
states that he produced rachitis by withholding lime, and increased the
effect by introducing lactic acid. By so doing, however, he changed
only the relation of the mineral to the organic substances, without
interfering with the normal proportions to each other of the
constituents of the ashes. Beneke, finding oxalic acid in the urine in
many cases of rachitis, attributes to it the want of calcification in
rachitis, and Senator suggests that what impedes the deposition of bone
might be formic, acetic, and lactic acids, which are also found in the
young osseous tissue.[6]
[Footnote 6: L. Fürth, _Path u. Ther. d. Rachitis_, Wiener Klinik,
1882.]
Of these statements many are uniform, others contradictory. Thus far,
they are not convincing except in one way--viz. that both withholding
and introducing certain ingredients, mainly lime, influence the growth
of the bone considerably. This may prove nothing else but that lime is
of paramount importance in the building up of bone, and that bone in
the period of rapid development is amenable to a great many influences.
It is in the period of rapid development that rachitis is observed.
Thus it occurs in every stage of intra-uterine and infant life. It is
met with in the foetus in very early intra-uterine life; it is found as
a congenital affection, continuing to develop after birth when it has
originated in the latter half of foetal existence; there is, thirdly,
the rachitis of early infancy; and, lastly, that of advanced infancy
and childhood. Of 624 cases of rachitis enumerated by A. Baginsky,
there were 256 less than a year old, 313 in the second, and 63 in the
third year. After this time rachitis is rare, as far as the active
symptoms of the disease are concerned. But still, a retarded form of
rachitis (r. tardiva) has been described by some authors. It is said to
occur about puberty, and to exhibit local changes in the bones of
genuine rachitical character, but to be wanting in all the other
symptoms required for the diagnosis of general rachitis. Such cases
have been described {142} by C. Lucas.[7] He found it complicated, now
and then, with albuminuria. The occurrence of the latter at that time
of life had been referred to by Moxon.[8] The principal symptoms
described by Lucas are scoliosis, talipes valgus, and genu valgum. The
epiphyses were slightly thickened; there were pain in the limbs,
languor, and pallor. In some of the cases there were also rachitical
deformities dating from infancy. He believes rachitis of adolescence to
exhibit more symptoms belonging to relaxation of the ligaments than to
softening of the bones.
[Footnote 7: _Lancet_, June 9, 1883.]
[Footnote 8: _Guy's Hosp. Rep._, 1878.]
A case of rachitis of undoubtedly congenital nature has been reported
by Chiari. There were but twelve teeth. There were no other alveoli,
nor was there any intimation of the formation of alveoli in the shape
of the jaw, which resembled very much the usual senile form of
retrograde metamorphosis.
Twenty years ago I described the lesions in part of a rachitical
cranium removed from an infant who lived up to her eleventh day. She
was born at full term with hernia of the brain, about one-sixth of
which protruded through the small fontanel. Only the cranium could be
studied with regard to rachitis, and but small portions of the frontal
and the anterior half of the parietal bones surrounding the large
fontanel could be removed. In these few square inches of bone there
were between twenty-five and thirty openings of the usual craniotabic
nature, nothing but a transparent membrane being left. The bony edges
of these thin portions were partly sloping off gradually, partly very
steeply, and somewhat thickened. They were distributed over the whole
part of the skull removed; some were found in the immediate
neighborhood of the points of ossification. No recent deposits of soft
rachitical bone had taken place under the periosteum. Thus, evidently,
the process was of rather an early date of intra-uterine life, and had
at birth run the full course of its usual development without having
had an opportunity to terminate in the restitution of the normal
bone.[9]
[Footnote 9: _Amer. Jour. Obst._, Nov., 1870.]
In a case reported by Dr. F. A. Burrall[10] the infant (female) was
cyanosed at birth, and had a small head and feeble general development.
The respiration was shrill and piping from birth, as though from
congenital laryngismus; in a few days it became raucous. The
post-mortem examination proved the larynx normal, with no obstructive
growths. She was pigeon-breasted, and the last phalanx of her right
finger wanting.
[Footnote 10: _Trans. N.Y. Path. Soc._, vol. i. p. 81.]
In the meeting of June 27, 1883, of the Société de Chirurgie of Paris,
Guéniot presented a newly-born baby with well-pronounced rachitis of
the extremities which had healed at the time of birth. The bones had
recovered their firmness, and the characteristic deformities remained.
In the meeting of December 19th he could report that the child had
exhibited neither symptoms of rachitis nor of syphilis since. In regard
to the latter, a very rigorous examination of the baby's whole family,
made by Guéniot and Fournier, resulted in the existence of no trace of
syphilis.[11]
[Footnote 11: _Rev. Mens. des Mal. de l'Enfance_, Janv., 1884.]
Kassowitz has examined many still-born infants, and also children dying
at an early age, at the foundling hospital of Vienna. In a large
majority of the cases he found rachitical changes in the ends of the
bones. In {143} many of those who lived several weeks he found rachitis
developed to such an extent that the presumption of its intra-uterine
origin became conclusive. Here nothing is left but the conclusion that
the cause of congenital rachitis has to be looked for in the condition
of the maternal blood.
Thus, the foetal and congenital occurrence of rachitis cannot be
doubted. Both forms are represented in literature. Neither requires the
presence of rachitis in one or both of the parents. But the cause of
the intra-uterine disease has not been found. Perhaps a disease of the
mother with considerable nutritive disorders or a defective placentar
supply may be found responsible. The foetal form runs its course long
before the normal termination of pregnancy; the congenital may have run
its full course at birth or complete it afterward. The bones are found
of characteristic nature, the diaphyses suffering more than the
epiphyses; even a rachitical pelvis has been met with by Fischer. Early
foetal rachitis is probably dependent upon a defective development of
the very first cartilaginous deposits and the first osseous nuclei;
thus, many of the congenital synostoses find a ready explanation.
Besides these, abnormal circulation is accounted for. For periosteal
proliferation at that early period contracts the foramina carrying the
blood-vessels, and, while interfering with the size of the bones, the
foramen magnum also. Thus, a certain class of cretinism appears to be
due to foetal rachitis, mainly of the base of the cranium, which
results in early ossification of the synchondroses, particularly of the
sphenoid bone. But lately I have seen a case of this description,
which, however, had not terminated at the time of birth. For after
birth the rachitical process developed further, and in addition to the
rachitical deformity of the base of the cranium there were afterward
thickening of the epiphyses, pigeon breast, and thoracic grooving and
flattening.
Rachitis is found in city and country, less on mountains than in
valleys. Still, it is met with at elevations of two thousand feet. In
the tropical regions it is almost unknown. Why it should have been
considered quite a new disease in England but a few centuries ago, or
whether it did not exist before that time, it is difficult to say. It
is certain, however, that deformities have been described in antiquity
which we are accustomed to attribute to rachitis.
As the disease is one that occurs during the period of rapid growth,
and is a developmental disease, everything that interferes with normal
growth and development is apt to change physiological functions into
pathological conditions and to produce rachitis. In the pregnant mother
her ill-nutrition and the defective cell-material used in the building
up of the embryo and foetus, or a defective placenta, may come in for
the explanation of foetal and congenital rachitis, although the case of
Klein's, who reports twins, of which one was normal and one rachitic,
is rather difficult to explain on that basis only. Even rachitis of
early infancy is not easily accounted for otherwise, for its first
symptoms show themselves at a very early period; thus constipation,
adiposity, and afterward craniotabes and thoracic grooving.
The common form, and that which is the usual subject of the text-books
and monographs, has, however, in most cases a well-marked preparatory
stage in the shape of diseases or ailments reducing sanguification
{144} and nutrition. Some cases are ushered in by, or follow the course
of, acute exanthems or acute gastric disorders or the presence of
entozoa. A larger number appear to result from insufficient oxygenation
resulting from lung diseases, with a long chronic ailment following the
acute stage. Even acute pneumonia, with its direct influence on general
nutrition, stands often for the proximate cause of rachitis. Bad air
alone, even swamp air, does not appear to be a sufficient cause. When
it seems so, it is complicated with the main cause of rachitis; that
is, bad, insufficient, improper food, with its immediate result--viz.
intestinal catarrh. Cow's milk, particularly when acid, starchy food
administered too early or in too large quantity or too exclusively,
early weaning followed by improper artificial food, insufficient
mother's milk or such as is either too thin or too caseinous, lactation
protracted beyond the normal limit,--may all alike be causes of
intestinal disturbances and rachitis.