Leprosy

by G. Armauer Hansen; Carl Looft

Danielssen states that he has seen, at the very beginning of the disease, a slight vaso-motor disturbance, which is indicated by a bluish-red reticular appearance, which is evident most clearly on changes of temperature. These vaso-motor disturbances, which appear as slight patches which can be induced by friction, are chiefly characteristic of the maculo-anæsthetic, though they may appear during the earliest stage of the tuberous, form.

In fact, our view is that the so-called prodromal symptoms are nothing more than the earliest, indefinite, undiagnosable phenomena of infection.

One or more eruptions of pemphigoid bullæ may occur in the commencing stage, but we have more often seen them later, both accompanying the patches and in the stage of anæsthesia and mutilation.

After a longer or shorter period the typical picture of the maculo-anæsthetic form develops; the spots either appear stealthily or they may appear all at once with marked fever. Several forms of the eruption are described by investigators; in our patients usually only the erythematous and the yellowish or brownish pigmented ones have been noted. Usually both forms are seen on the same patient, for the simple erythematous spots become in time more and more pigmented—usually only at the periphery, where a bluish-red play of colours is often seen. Those eruptions which are all along pigmented and which develop very gradually, we have particularly noted in the intercostal spaces. Various forms—round, oval, gyrate—have been observed. The patches may be perfectly flat, or slightly elevated. The size varies from that of a pea up to that of the palm of the hand, and they may be even larger. At the commencement, we have usually found these patches hyperæsthetic; anæsthesia is only found in the older patches. They do not always at once attain their full size; we can often observe their growth; one may run into another, and then the initial form is lost. The number and extent of these patches are very varied; some patients present great map-like eruptions on the face, back and extremities; in others the patches are few and scattered. The seat of these patches corresponds in general to that of the nodules, but the back and the intercostal spaces are frequently the seat of patches, while on these areas nodules are only rarely, if ever, present. [Plate IV] gives a good picture of the patches in the maculo-anæsthetic form—duration, two years. The white centres and the slightly elevated reddish edges are very well shown. A symmetrical distribution of the patches strikes one, and has been regarded as indicative of a central localisation of the leprous poisons of which the patches are a tropho-neurotic vaso-motor symptom; but in many cases there is absolutely no symmetry, and the discovery of bacilli in the patches themselves proves them to be the direct result of the action of the lepra poison. The lymphatic glands corresponding to the position of the patches are always swollen, and the swelling may persist long after the disappearance of the patches. The duration is very varied; some are gone in a few days or even less, others may last for years. Pigmentation of the periphery and pallor of the centre indicate that the patch is already old, and the pallid centre is always anæsthetic, the anæsthesia affecting all, or only some perceptions. The signs which Hillis indicated, as diagnostic of the patches of the anæsthetic from those of the tuberous form, we cannot recognise. The patches of the tuberous form are certainly usually thicker, indicating a greater degree of infiltration, than the anæsthetic; but as both are caused by the lepra bacillus it is evident that they may be absolutely similar.

PLATE IV.

The longer the disease lasts the more does the neuritis predominate; the ulnar and peroneal trunks may be felt to be thickened, they are sensitive to pressure, and, if carefully felt for, the peripheral finer branches may be felt as delicate thickened cords. In one case we were able to feel the cutaneous nerve branches in a patch, growing daily more and more thickened, in contrast to the large not especially affected nerve trunk. The large palpable nerve trunks are not equally thickened in their whole length, but the thickening appears about the joints where the nerves run across bone.

The symptoms of this neuritis are various; at first neuralgia, and later, widespread anæsthesia, with trophic disturbances, such as the formation of pemphigoid bullæ; we have often seen hydrarthrus and pains in the joints. Motor pareses and paralyses are never absent, but they are not, as Neisser argues, due to a leprous affection of the muscles, but are a secondary neuritic symptom, as we have discovered from anatomical examination of the muscles. As the neuritis especially affects the peripheral nerve trunks, we find the secondary symptoms in the peripheral regions, usually only in the extremities and on the face. We will now more closely consider the various nervous symptoms.

Neuralgia is usually present in the extremities, in the ulnar and peroneal regions. The anæsthesia relates to the different qualities of sensation, and is not only present in the patches, but progresses gradually from the periphery toward the centre, so that at last the whole extremity, and often also parts of the trunk, become anæsthetic; the face is always more or less anæsthetic. We have often found thermal anæsthesia present alone, or accompanied by anæsthesia or analgesia. The anæsthesia may become more and more extensive, or it may very gradually disappear, indicating that the neuritis of the affected nerve has disappeared.

Trophic and vaso-motor disturbances are never absent if the neuritis is pronounced and lasts for any time; the skin may become œdematous, or it becomes thin, shiny, and slightly scaly (glossy skin). We have often seen, especially if the neuritis has lasted long, and the later symptoms such as mutilation have commenced, dark-coloured hyperkeratoses, usually symmetrical on the front of the leg, or on the dorsal surface of the hands. In one patient we observed on the toes horny, thick (1.5 cm.) symmetrically placed formations, which when thrown off left a new-formed rosy-red skin, with intact sensibility; the patient had on the front of the leg the appearances of ichthyosis.