Leprosy

by G. Armauer Hansen; Carl Looft

The lymphatic glands (cervical, axillary and inguinal) in relation to the affected skin and mucous membrane are always swollen: this leprous swelling is always indolent, and never goes on to suppuration. Sometimes the glandular swelling may aid in the diagnosis, if the skin affection is not absolutely characteristic, though this is most rarely the case.

The nodules are almost always seated in the cutis, but they may, though rarely, be placed deeper in the subcutaneous connective tissue; they form then no projections, but the skin over them is almost always somewhat hyperæmic and bluish-red, and, if the finger is passed over the place, the thickening or the nodule may be felt in the deeper parts. It is in our experience that a patient who had only this form of nodules was regarded by a colleague, well acquainted with the disease, as free from Leprosy, probably because he did not use his fingers.

From the symptoms described above, the diagnosis is almost always very easy, and we ourselves know of no disease of the skin which can be confounded with nodular leprosy. If necessary a piece of skin may be removed and examined for the presence of bacilli, which, at least in the nodular form of the disease, are never absent. This, we have once had occasion to do.

In addition to the skin the nerves are also affected, not always at the commencement, but always in the later stages. Whether all peripheral nerves are affected we cannot say—certainly the facial, radial, ulnar, median and peroneal are always diseased. According to our investigation the nerves of the extremities are affected throughout their whole length, but the affection is severe only at certain places, viz., where the nerves run superficially over bones or joints, as the median at the wrist, the ulnar at the elbow, and the peroneal where it crosses the fibula. As a result of this nerve affection we have pain followed by anæsthesia. The pains in the arms, hands, feet and calves are sometimes very severe and persistent. The affection at first causes pain, by pressure on the nerves, and later—when the pressure has led to atrophy—anæsthesia. Now since, as we shall later clearly demonstrate, leprous affections tend to heal, it is not infrequently the case that nerve affections, when slight, pass off without having specially injured the nerves, and these nerves may be the seat of fresh infections, and thus the patient suffers from repeated painful attacks through a course of years. This is particularly the case where there is general infiltration of the legs, and is either the result of repeated attacks of the same, or of the implication of different nerve branches. The nodules are often painful when first developed, but later on sensation is deadened.

Of internal organs, the testicle, liver, and spleen, are always affected in this form, but we shall consider them later in the description of the pathological anatomy.

Before we more closely describe the course of the disease, we shall first briefly discuss the fate of the nodules. These usually remain for years unchanged, growing very little or not at all. The skin over and around them, or rather its vascular supply, is very sensitive to changes of temperature, so that the skin, as we have already indicated, changes its colour with change of temperature from dilatation of the blood vessels. The vessels evidently suffer from the invasion of the leprous poison. New outbreaks have often the appearance of an “erythema nodosum,” with great hyperæmia. We had once the opportunity of examining a piece cut out of such an erythema-like eruption, and found dilated vessels and round cells, and only after long search a few bacilli. One must conjecture that there is deposited with the bacilli a chemical poison which affects the vessels, or that the bacilli produce the poison, and that this poison has its action only in its immediate neighbourhood.

But occasionally the nodules grow so luxuriantly that the epidermis develops furrows and clefts which may reach down to the nodules, and then a bloody fluid comes out of them which dries up on the surface to a reddish brown scab. Or it may happen that the upper horny layers of epithelium disappear, and that only a few rows of cells of the rete Malpighii remain. In this case the exuded fluid less often dries, the surface is usually blood-red and moist, and appears like an ulceration, though it is not really one. When this takes place on the face, particularly on the lips, or on the backs of the fingers, the sufferings of the patient are very much increased. After several years the nodules usually soften about the middle of their base, and the nodule may sink in over the softened part; or they burst, the softened part is thrown off, and now is developed the true ulceration by which the nodule may be completely eliminated and sunken stellate scars alone remain.

The determination of the commencement of the disease is exceptionally difficult, indeed impossible, for it must always be founded on the statements of the patient, and the patients either observe themselves insufficiently, as may frequently be noted, or they conceal many facts. As a matter of fact we do not know the earliest symptoms of the disease. According to Danielssen and Boeck, the patients often suffer long and repeatedly, before the outbreak of the disease, from weakness, with rheumatoid pains and fever. This the patients frequently corroborate. But we are inclined to regard these attacks of fever as indications of the already existing disease. It appears to us more probable that the disease begins with some form of local affection which is so indistinct that the patient himself does not notice it, or at least lays no weight upon it, and that these local affections are analogous to others with which we are familiar, namely, the nodules which may last for years before new and such definite eruptions appear, that the disease cannot any longer be ignored or kept secret. We believe therefore, that the patients do not really know when they commence to be ill, and that they date the beginning of the disease from a later eruption. If at the commencement only the extremities are affected the patients may conceal their condition for years, and through this concealment become so accustomed to lie, that later it is impossible to receive from them correct information.

The cases are very frequent in which the patients have for several years only scattered nodules, and then suddenly a fresh outbreak of numerous nodules. The disease always advances by outbreaks of eruptions which repeat themselves at longer or shorter intervals. It is very often the case that the older nodules soften during a fresh outbreak, and completely or partly disappear; and these outbreaks are always accompanied by fever, the temperature rising to 39° or 40° Cent. Now we know that the nodules, if the patient is affected by another febrile disease, may disappear. It is, therefore, difficult to decide whether the disappearance of the nodules is the cause or the result of the eruptive fever. But we possess certain observations in which the disappearance of the nodules has begun before the onset of the fever, and in which, therefore, the fever and the later eruption appear to be caused by the softening of the nodules. Supported by these observations we regard the eruptions as auto-infections, in which bacilli (or poison) from the older lepromata pass into the blood, and thus new areas of the skin or other organs are affected. We have often observed that an irido-cyclitis, or an affection of the throat, arises during an eruption, and also that the nerves beneath the nodules become swollen and painful, and once we have seen the testicle become swollen and painful during an eruption. As to the affections of the liver and spleen we have no clinical observations; they appear to cause no clinical symptoms, or at all events, such indefinite ones that, although our attention has been directed to them, they have escaped observation.

The eruptions are of the most varied duration. Some last only a few days and cause so little fever that the patients experience no particular disturbance to health; they only know that a few new nodules appear, or that they are sore about the throat. Others last for weeks, indeed, months, with remittent fever, the temperature rising to 40°. Quinine has no effect. During such eruptions the strength of the patients is of course distinctly diminished, but when the eruption is over they recover rapidly and feel themselves all right again; only they are more leprous than before, or at least have more leprous manifestations. The number of eruptions varies greatly in different cases. Sometimes the patient has, for several years, several eruptions every year; in other cases the eruptions appear only very rarely—one or two in the whole course of the disease, and they may be very slight. It appears as if the bacilli in different cases were of varying virulence, or possibly the structural conditions are different in different individuals, so that in some the bacilli (or the poison) reach the blood more easily than in others.