DIAGNOSIS AND PROGNOSIS.
DIAGNOSIS.--In view of the description which we have given of the two
forms of the disease, the diagnosis is usually accompanied by little
difficulty. We have, however, noted above how a case of tubercular
Leprosy, with subcutaneous nodules only, was overlooked by a doctor
well acquainted with the disease; and we have occasionally seen, in
the country, people described by the doctors as leprous who were not
so. And, on the other hand, we ourselves were once in doubt as to the
diagnosis in a tuberous case, since all the nodules were exceptionally
small, and presented no characteristic appearance. But the doubt was
readily dispelled by the excision of a nodule and the recognition
of the bacillus. In the diagnosis of the maculo-anæsthetic cases,
one is more frequently in doubt, since the maculæ have not always a
characteristic appearance; sometimes they closely resemble psoriasis,
and in such cases the excision and microscopical examination of a
portion might clear away doubt. This we have never needed to do, since
the swelling of the lymphatic glands, or a thorough investigation
of the sense of touch, have always been sufficient to establish a
diagnosis. Even in comparatively, recent cases there may almost always
be detected some loss of sensation in the fingers and toes; sometimes
it is first evident on the wrists or back of the feet. For this
investigation one must either use callipers, or very slight stroking,
since deeper _pressure_ can be at once perceived. As a rule, the
maculæ themselves are somewhat anæsthetic. We recollect once seeing a
syphilitic eruption exactly resembling the leprous maculæ, but here the
history cleared up the diagnosis.
Maculo-anæsthetic Leprosy may in its later stages be confounded with
syringo-myelia, as Charcot has already noted in giving the points of
distinction between the two conditions. If the maculæ are no longer
present, careful investigation will often enable one to recognise their
previous presence by finding areas of skin, especially on the upper
arms, the back, the thighs and calves, which are somewhat paler than
the surrounding skin, and in which sensation is somewhat blunted. We
have thus frequently recognised the previous presence of maculæ in
patients who themselves knew nothing of them. Zambaco Pasha has stated
that certainly many of the cases described in France as syringo-myelia
and Morvan’s disease are cases of Leprosy; that Leprosy in this form
still exists in Brittany; and further, that he has there found some
cases of nodular Leprosy. It is remarkable that in these last cases,
where the proof would have been so easy, he has not demonstrated the
Lepra bacillus. From the drawings which he gives in the _Annales de
Dermatol. et de Syphil._ (T. III., Nr. 12), some of the cases can
scarcely be regarded as Leprosy, since on the hands with mutilated
fingers, no muscular atrophy can be noted; but in others there is
distinct atrophy, and these may very well be leprous, the more as
Pitres has published in the _Gaz. des hôp._ 1892, a case diagnosed as
syringo-myelia in which Lepra bacilli were demonstrated in an excised
portion of the ulnar nerve. It is unfortunate that Zambaco Pasha did
not demonstrate the remains of previous maculæ, which would probably
have been possible in some cases, were they really cases of Leprosy.
According to the rich experience of Dr. Danielssen and our own, it
must be admitted that a skin eruption is never absent in true cases of
Leprosy. With multiple neuritis from some other cause, it is, with a
good history and careful examination, not possible to confuse Leprosy;
and the same is true of progressive spinal muscular atrophy, where
there is no disturbance of sensation.
PROGNOSIS.--The prognosis is very different in the two forms. As
we have already stated, both forms may recover, since all leprous
products may disappear without any fresh ones appearing. _In nodular
cases this is a very rare exception, while it is the rule in the
maculo-anæsthetic._ Recurrent outbreaks are almost invariable in
nodular cases, and in them, too, nephritis is an almost constant
occurrence. Patients rarely live more than eight or nine years after
the definite outbreak of the disease. As already remarked, we cannot
state that Leprosy of itself is responsible for the end; we are rather
inclined to regard the nephritis and other complications as the direct
cause of death. The patients usually die long before the disease has
run its course. But in the maculo-anæsthetic form the cure of the
Leprosy is almost invariably the result. What remains, however, after
the cure of the leprosy, is very different. We have occasionally a
complete subject with vigour and good health, but usually only a
miserable rudiment of a human being, with more or less paralysed and
deformed hands and feet, with unclosable eyes, of which the lower part
of the cornea is opaque, and from which the tears run down over the
cheeks, and with paralysed facial muscles unable to close the mouth, so
that the saliva constantly dribbles from it. Such cases may, however,
live long and reach great ages, if under such circumstances this can be
looked upon as any advantage. They die usually from some intercurrent
disease.