This section is from the book "A Treatise On The Materia Medica And Therapeutics Of The Skin", by Henry G. Piffard. Also available from Amazon: A Treatise On The Materia Medica And Therapeutics Of The Skin.
Leprosy is a constitutional affection characterized by marked and peculiar changes in the skin and other organs of the body. It presents three principal forms, known as the macular, tubercular, and anaesthetic. These are usually associated together in varying degree in each case, although one of them, as a rule, predominates over the others.
Before the disease becomes sufficiently advanced to present distinct and characteristic symptoms, there usually exists a prodromal stage, of greater or less, often of years, duration. During this period there may be nothing to particularly attract the attention to leprosy, and the only evidence of ill-health may be a feeling of languor or loss of force, with sometimes mental depression. Occasionally a brownish discoloration (macule), or an isolated bulla, may appear from time to time, the first usually healing before the second makes its appearance. Later, the macules become more numerous and larger, from the size of a coin to that of the hand, but it is difficult to appreciate with the fingers any thickening or infiltration. The patches at first are of a reddish brown, and as they increase peripherally their advancing border maintains this color, while the central portions gradually lose it, and fade into a dirty gray, and sometimes to a dead white. Occasionally the macules disappear entirely without leaving any mark. When the patches first appear they are commonly hyper-aesthetic, but as the disease advances, this condition gradually disappears, and ultimately the white patch becomes anaesthetic.
In company with the macules, or independently, tubercles may arise. These are thickened elevations of the skin, sometimes quite circumscribed, at other times more diffuse. The tubercles at first may be hyperaesthetic, later becoming anaesthetic. They may appear on any part of the body, but very frequently make the face their favorite seat, locating themselves above the eyebrows, and on the nose, lips, and ears. When they are developed to any great extent, they render the features extremely repulsive and disgusting. The tubercles may persist throughout the whole course of the disease, or, on the other hand, undergo ulceration, or disappear interstitial absorption. Coincidently with these changes, or later, the mucous membranes of the buccal cavity, nares, pharynx, etc., may present similar lesions.
The anaesthetic form of Leprosy may arise as a late stage in the course of a case that at the beginning had exhibited macular or tubercular features only, or it may appear without such tubercular development. The principal cutaneous lesions met with at the commencement of this form are bailae. These vary in size, and persist for a short time only. Commonly they rupture, and leave a stained surface which in time becomes the seat of anaesthesia. Hyperaesthetic patches may appear from time to time, and persist for mouths or longer, and be ultimately succeeded by anaesthesia The anaesthetic portions of skin may also undergo a certain degree of atrophy, which process may involve the subcutaneous tissues, and result in ulceration. and if situated upon the hands or feet, to caries of the bones of these parts. The distal phalanges are the first to suffer, later the others, so that in time all of the fingers and toes may drop off. In this form, especially, changes in the ulnar nerve, at and just above the elbow, can usually be appreciated with ease, the nerve becoming swollen and tender.
The course of Leprosy is chronic, five, ten, or fifteen years elapsing before the patient falls a victim to the disease, usually through medium of some intercurrent affections.
In advanced cases, the diagnosis presents no difficult, as the features of the disease are exceedingly characteristic. I can im-agine, however, that it might be mistaken for syphilis, by those who are in the habit of calling every severe case of skin disease, that they do not know the name of, Syphilis. In the earlier stages, before the cutaneous lesions appear, great difficulty might be experienced, especially in countries where the disease is not of frequent occurrence. Even here, however, it is possible that early changes about the ulnar nerve might give a clue to the nature of the disease, which inquiry into the patient's history, former places of residence, etc., might confirm. The macular form might be mistaken for vitiligo, but a careful comparison of the two diseases need not leave the inquirer long in doubt.
The prognosis of Leprosy is, without question, very unfavorable. So far as it is possible to get at the facts, a few cases of Leprosy appear to have been cured, a larger proportion have been benefited, but in a still larger portion, the progress of the disease has not been stayed
Further than the fact that Leprosy is frequent in some parts of the world,* and rare in others, we know very little regarding the immediate causes that tend to produce the disease. Hygienic and climatic influences have been supposed to be potent in the production of the disease, but it has been found that these influences are not identical in character in the different localities where this disease is most prevalent, as the disease appears to flourish as freely in Norway and Iceland, as in tropical and equatorial latitudes. Hereditary influence is an important and acknowledged factor, though many cases are met with which cannot be attributed to this influence. The question, however, as to the transmissibility of Leprosy from one person to another, is of vital importance.+ In other words, is the disease contagious or infectious in any degree or manner. In the opinion of the majority of East Indian medical officers, ++ the disease is not contagious. As further negative evidence it may be stated that for several years (from 1864 to 1869), there was a leper patient in the Bellevue Hospital. During a portion of this period another leper acted as nurse in one of the wards. These lepers were of course in contact with many hundreds of persons, and yet from that to the present time, there has not been a single case of leprosy observed in this city in persons who were, during the years mentioned, residents of the city. Per contra, we know that whop Leprosy has once gained a decided foothold in any locality, it is apt to spread with great rapidity thereafter. A recent writer, ** moreover, takes very strong ground, and brings much evidence in support of the view that the disease is, in some way, transmissible. A careful review of the evidence presented on both sides, leads me to the conclusion that probably Leprosy, like Syphilis, is not transmissible by ordinary contact and association, but if the blood or secretions of a leper gain access to the system of a healthy person, the latter may, in this way, contract the disease.