By Carroll Dunham, M.D., New York.

Dr. Copeland says that the ancients comprehended under the names “psora” and “scabies,” besides itch, properly so-called, eczema, prurigo, lichen, and ecthyma; and modern medical writers, up to the year 1834, have given nearly the same extent of application to the name Itch and its synonyms in the various languages of modern Europe. Thus, for example, we find Hahnemann including under the name “itch,” “tenia capitis, and all eruptions which become moist on being scratched ” (eczema, therefore, and impetigo) as instances of cutaneous affections originating in what he calls a “psoric miasm.”

It was not until the year 1834 that the presence of an insect in the vesicles of a certain cutaneous eruption was generally acknowledged. This fact became forthwith the basis of a new subdivision of vesicular eruptions by which the name“ itch” or “scabies,” was restricted to that form which was characterized by the presence of the “acarus scabiei” or “ itch-insect” in the vesicles. Itch, then, in this severe and restricted use of the name, is a disease our generally accepted knowledge of which dates from the year 1834. What is found respecting itch in medical works anterior to 1834 is to be understood as applying equally to eczema, lichen, prurigo, etc., and it must be borne in mind that, among all the cases described in many such works, there may not have been a single case of what we now call true itch, i. e., itch characterized by the presence of the acarus. We shall henceforth use the term “itch” in this restricted sense.

In the study of this, so to speak, new disease, many questions have had to be considered anew which had been already determined with greater or less certainty as regards the diseases formerly confounded with itch.

The first in importance, in its bearing both upon prognosis and upon treatment, was the question of the nature of itch, whether it were a local or a constitutional disease. And although, as Homoeopathicians, we have not so large a faith in the doctrine of purely local diseases as our brethren of the old school have, yet, in this case, the question has the greatest interest even in our eyes. For, a disease in which a parasitical insect plays so important a part as the acarus is by many assumed to play in itch, is just one of those very few affections which may be purely local, dependent solely upon the presence of the insect in the vesicles. In this case it would resemble those troublesome affections caused by the presence under the skin of the woodtick and “jigger” (chiggre, pulax penetrans) in the southern part of our country and of the Guinea worm in Africa, and for the cure of which, nothing further is needed than the expulsion or destruction of the insect.

The question is, then, does the continuance of itch in any case depend solely upon the continued life and activity of the insect? Or, what is the same thing will the destruction of the insect in every case ensure the disappearance of the disease?

For the solution of this question direct experiments have been made on a large scale; while at the same time the results of treatment offer a large mass of indirect evidence. It is the object of this paper to bring into view these classes of testimony and to consider their bearing on the question of the nature of itch.

The existence of the insect in itch vesicles was popularly known long before it was acknowledged as a constant fact by scientific men, and Sulphur was in high repute among the people as a remedy for itch. After the general recognition of the acarus as an essential element of the disease and the consequent establishment of a more stringent diagnosis, the experience of medical men in hospital practice soon justified this high regard in which Sulphur was held. The remedy was used both internally and, in the form of ointment, externally, and of its curative action no doubt was, or could be entertained.

When, however, the question of the nature of the disease, as to whether it were a constitutional or a purely local malady, came to be mooted, it was suggested that the Sulphur acted curatively only when externally applied, and that its action was limited to the destruction of the insects, upon the extermination of which, it was alleged, the disease of course disappeared.

Experiments were instituted to test this hypothesis. A number of acari being caught, were subjected to the action of Sulphur. They perished in the course of a few hours. Others, which were at the same time buried in Lycopodium powder or in flour, retained a vigorous vitality for more than a day. It was thus demonstrated that Sulphur has the power of speedily destroying the acarus, and this was held to account for the speedy cure of cases of itch in which Sulphur had been applied externally.

Hebra, of Vienna, carrying out these experiments more extensively and more rigorously, reasoned, that if the disease depend solely on the presence of the insect and disappear with the destruction of the insect, then a cure might be effected by the local application of any substance, even of a non-medicinal substance, which might possess the power of speedily killing the acarus. He therefore caught a number of insects, and, among other experiments, plunging several into lard and other kinds of grease, found that they perished in a very short time. He accordingly treated a very large number of patients by simple inunction with lard or oil, and with, as he reports, complete success.

These experiments made on an extensive scale and corroborated by the reports of other observers, seem to demonstrate the fact that itch is a local disease, originating in, and depending solely upon the presence of a parasitical insect, and requiring therefore for its cure, simply the extermination of this insect.

There are, however, certain incontestable facts which cannot be accounted for by this simple view of the disease.

1st. Itch may be cured, as has been proved again and again, by both Allopaths and Homoeopathicians, by the internal use alone, of Sulphur; but this treatment, as a general rule, requires a considerably longer time, than when external applications are conjoined with it, or are used alone. A disease, however, which thus yields to a purely internal treatment, can scarcely be deemed a local disease. An hypothesis it is true has been advanced to account for these cures and at the same time to avoid admitting the constitutionality of the disease, viz., that the Sulphur, absorbed into the circulation, is deposited in the vesicles, and thus, by a species of local application, kills the acarus and cures the disease. But this is an untenable over-refinement and will certainly not hold good with reference to those cases which are cured by Homoeopathicians with infinitesimal doses of Sulphur.

2nd. Devergie affirms that in those cases of itch which have been “cured,” so to speak, by the simple inunction of lard or analogous substances, the eruption reappears after a time more or less brief, while this is not the case where patients have been treated with Sulphur, either internally or externally. Yet the inunction of lard undoubtedly kills the acarus, and, if this be all that is needed for the cure of the disease, we are at a loss to account for its reappearance after the one treatment and not after the other.

Hebra is silent respecting the reappearance of the disease in the numerous cases reported by him as treated by simple inunction; indeed, from the nature of his hospital practice, we know that he must have lost sight of almost all of his patients very soon after his treatment ceased. Devergie, on the contrary, has very great opportunities for observing the secondary results of treatment, the Hospital St. Louis being a kind of winter poorhouse.

3rd. Devergie, moreover, warns his pupils emphatically against the treatment of itch by the external application alone of either Sulphur or simple lard - assuring them that serious lesions of internal organs not unfrequently follow these speedy cures.

Now it is pretty generally admitted, that the sudden suppression of eczema and analogous eruptions by external applications, is attended with considerable danger, and this is accounted for by the assumption that these are constitutional diseases; and they are so considered on this very account, namely, because a local treatment fails to eradicate them but merely changes their seat in the organism. But, according to Devergie and other medical writers, itch when locally treated manifests the same phenomena of lesions of internal organs. By parity or reasoning therefore, itch is to be adjudged a constitutional disease.

4th. Finally, Hebra relates that, in order to solve the question of the propagation of itch, he inoculated himself and some of his friends with the fluid discharged from the itch vesicles but without effect. He then placed acari in an active state upon his hands and the hands of his friends, but without any result. He finally inserted several of them beneath the skin of his hand and left them there. For several successive days he looked in vain for traces of them. On the sixth day, after considerable febrile symptoms and other signs of constitutional disturbance, he noticed in his groin vesicles resembling itch-vesicles, but not containing acari. On the eighth day vesicles containing acari were first discovered on the hands.

A more perfect picture of the onset and development of a constitutional disease could scarcely be imagined than this history furnishes. Were this disease simply the presence of a parasite beneath the skin, its inconvenient symptoms would have appeared as soon as the acarus was introduced under the skin by Hebra. If one walk with unprotected ankles in a southern wood and thus expose himself to the “jigger,” not a single hour elapses before he feels the tingling smarting which ceases only when the insect has been removed or destroyed. With the itch, on the contrary, eight days passed away before local signs were observed, and the first indications of disease were fever and an eruption on a distant part of the body.

With the evidence thus cited before us, we are in a position to assume that itch is a constitutional disease. The manner of its onset, with constitutional disturbance, several days after the inoculation of the insect, all traces of the inoculated insect being meanwhile lost, these facts together with the effects of its too speedy suppression, compel us to this conclusion.

On the other hand we are constrained to concede to the acarus an important part in the disease. It is admitted on all sides that he is the sole agent in its propagation from one individual to another. And it is also proved that his destruction in the vesicles greatly facilitates the radical cure, and in every case causes at least the temporary disappearance of the eruption.

These facts, most important in a practical point of view, have seemed to me to present a basis for a satisfactory theory of the disease which shall acknowledge the important functions exercised by the insect and shall at the same time affirm the constitutionality of the disease.

And in this connection, a reference to the morbus pedicularis may not be inappropriate, at least, to that variety in which the parasite is the pediculus corporis.

So persistent is this disease, in some cases, in spite of the utmost cleanliness and care, and so speedily, in the course even of a few hours, do the patient's body and its surroundings swarm with incredible numbers of the vermin, after so thorough a cleansing that not one had been discoverable, that authorities so recent and so eminent as Rayer and Devergie have felt constrained to admit the doctrine of spontaneous generation in the case, at least, of these parasites and to assume that they were generated in or upon the bodies of certain persons by virtue of a constitutional taint or miasm.

Erasmus Wilson does not admit the doctrine of spontaneous generation. He thinks that if due allowance be made for the “prodigious fecundity,” of these insects, their speedy reappearance in the innumerable hosts referred to, may be understood. But when called upon to account for their persistent reproduction on certain persons while others quite as likely to come within reach of their ova are not infested at all, he is obliged to assume that the skin and excretions of certain persons, by reason of some constitutional peculiarities of those persons, furnish a favorable nidus for the development of the ova and of the resultant insects. He says,

“It is difficult to understand the extraordinary increase of these creatures on the skin, in certain cases, even among persons of cleanly habits and we cannot but come to the conclusion that certain states of the fluids of the body are peculiarly favorable to their nourishment. Then, they are sometimes found to be produced during an illness and, in some families, have been known to invade the body shortly before death, and so become an admonition of the approach of death.” And, speaking of the treatment of this affection, Serrurier, after dwelling on the advantages of cleanliness and of diverse external applications which kill the insect, says, “When, as is most often the case, the phthiriasis depends or seems to depend on some constitutional disease, the local treatment will be but palliative and no cure can be effected without combating the constitutional disease by constitutional means.”

And, passing for a moment, to still another variety of parasites, the opinion is gaining ground, among students of Natural History, that the ova or the lower forms of intestinal worms are very generally diffused and that very few human beings are not continually receiving them into the system; but that these ova, in the majority of individuals, perish and that they develop only in the bodies of those persons in whom the fluids and secretions are of such a character as to favor their development and that, furthermore, the fluids and secretions are in such a state as to favor the development of the worms only when the individual is in a diseased condition. It follows from this that there is a diseased condition, which precedes and prepares the way for the development of worms; there is, so to speak, a stage of helminthiasis in which, as yet, no worms exist as such. This explains the not unfrequent removal of what are known as “worm symptoms,” while yet no worms are evacuated. If this be the true view, it would follow that drugs, if there be any which merely kill the worms, without affecting the patient, would be only palliatives. They would not change that morbid state of the patient which favors the development of the omnipresent ova and there would be a speedy relapse.

Just so, it may well be that the ova of the acarus scabiei and of the pediculus corporis respectively develop only on the body of a patient whose fluids are so changed, under the influence of some diseased state, as to be favorable to their development. If this be so no external local treatment, addressed chiefly to the destruction of the insect, could be other than palliative. The ova being almost universally diffused would soon develop again in this favorable nidus. However such external destructive means might seem to expedite a cure, the only radical curative would be a constitutional treatment which should make the body unfit for the development of the vermin.

Recurring now to the subject of the morbus pedicularis, we observe that Attomyr states that in proving Psorinum he witnessed the production of body lice. This statement was called in question by many of his colleagues, among others most vehemently by Griesselich, the authority of whose criticism however, is weakened by the consideration that he doubted and denied everything. But Attomyr affirms that he cured several cases of morbus pedicularis with Psorinum. This too was doubted. It is remarkable, however, that the elder Rapou of Lyons, without knowing Attomyr's clinical experience, gave Psorinum successfully in a very obstinate and strongly marked case of the disease and subsequently treated a large number with it with uniform success.