LEPROSY:IN ITSCLINICAL AND PATHOLOGICAL ASPECTS.Chapter I.INTRODUCTORY.
LEPROSY:
IN ITS
CLINICAL AND PATHOLOGICAL ASPECTS.
The Bacillus Lepræ has now been recognised in all leprous products, and although the fact has not yet been experimentally demonstrated, we may practically say with confidence that Leprosy is a chronic disease caused by the Lepra bacillus.
Leprosy appears in two forms, which are clinically pretty sharply distinguishable, and were named by Danielssen and Boeck “nodular” and “anæsthetic.” This nomenclature, introduced by these authors in their pioneer work,Om Spedalskhed, Christiania, 1847,Traité de la Spedalskhed, Paris, 1848, is so far important as it characterizes the common and most prominent symptoms of the two forms, viz., in the one, the nodular eruption on the skin,in the other, the anæsthesia which results from the widespread affection of the nerves. On the other hand, regarded from a strictly scientific standpoint, the nomenclature is scarcely the happiest: firstly, because the one form is named from the eruption on the skin, and the other from the results of the affection of another organ, the nerves; and secondly, because the nerves are affected in the nodular as well as in the other form, though the result of the affection, the anæsthesia, does not so dominate the appearance of the disease.
As Danielssen and Boeck recognised, skin eruptions are present in both forms, and since, as we shall later point out, the eruptions differ both clinically, and also somewhat in their anatomical formation, it would perhaps be more strictly correct to describe the two forms as Lepra tuberosa (tuberculosa) and Lepra maculosa or lævis. But, in the first place, it is of questionable advantage to change a universally accepted nomenclature; and secondly, it is very frequently the case that one sees the patient for the first time after the disappearance of the macular eruption with anæsthesia only, so that the name Lepra anæsthetica exactly describes the case. But in order to give to the skin eruption in the anæsthetic form its proper place in the nomenclature we will describe the two forms of the disease asLepra tuberosa(tuberculosa), andLepra maculo-anæsthetica. And thus we hope to have done justice both to the founders of the scientific study of Leprosy, and to the clinical appearances of the disease.
Danielssen and Boeck have also described a mixed form of the disease, in which nodular Leprosy is combined with anæsthetic. Sometimes the skin eruption disappears and the nodular form passes into the anæsthetic, and sometimes, though much more rarely, the anæsthetic into the nodular; and since, further, the two forms are so different in their clinical appearances that they look almost like different diseases, the recognition of a mixed form might appear to be justified. But since every case of nodular Leprosy is accompanied by affection of the nerves and anæsthesia; and the natural termination of every case of nodular Leprosy is to pass into the anæsthetic form, if only, as occasionally happens, the patient live long enough; and since the skin eruptions of the maculo-anæsthetic form are characterized, just as those of the nodular form, by the presence of the leprosy bacillus, we regard the transformation of a case of maculo-anæsthetic into nodular Leprosy only as a sign of the unity of the two forms, and we delete altogether the name of mixed Leprosy. Otherwise every case of nodular Leprosy must, at all events after some years of existence, properly be called“mixed,” for in such cases anæsthesia is never absent.
It has been attempted to indicate as a special form of the disease a Nervous Leprosy, in which no characteristic skin affection is present.[1]In view of what we have noted above, that nerve Leprosy is present in both forms of the disease, and that an eruption may be noted at some period in all carefully observed cases of the disease, this attempt to indicate a special nerve Leprosy is evidently wrong.
We will first of all discuss separately the two forms of the disease, the nodular and the maculo-anæsthetic, and then proceed to demonstrate the unity of the disease in spite of the differences in form.