an eruption which differs markedly according to the type of
disease. In the nodular form dark red or coppery patches appear
on the face, backs of the hands, and feet or on the body; they
are generally symmetrical, and vary from the size of a shilling
upwards. They come with one of the feverish attacks and fade
away when it has gone, but only to return. After a time infiltration
and thickening of the skin become noticeable, and the
nodules appear. They are lumpy excrescences, at first pink but
changing to brown. Thickening of the skin of the face produces
a highly characteristic appearance, recalling the aspect of a lion.
The tissues of the eye undergo degenerative changes; the
mucous membrane of the nose and throat is thickened, impairing
the breathing and the voice; the eyebrows fall off; the ears and
nose become thickened and enlarged. As the disease progresses
the nodules tend to break down and ulcerate, leaving open sores.
The patient, whose condition is extremely wretched, gradually
becomes weaker, and eventually succumbs to exhaustion or is
carried off by some intercurrent disease, usually inflammation
of the kidneys or tuberculosis. A severe case may end fatally
in two years, but, as a rule, when patients are well cared for the
illness lasts several years. There is often temporary improvement,
but complete recovery from this form of leprosy rarely
or never occurs. The smooth type is less severe and more
chronic. The eruption consists of patches of dry, slightly discoloured
skin, not elevated above the surface. These patches
are the result of morbid changes affecting the cutaneous nerves,
and are accompanied by diminished sensibility over the areas of
skin affected. At the same time certain nerve trunks in the
arm and leg, and particularly the ulnar nerve, are found to be
thickened. In the further stages the symptoms are those of
increasing degeneration of the nerves. Bullae form on the skin,
and the discoloured patches become enlarged; sensation is lost,
muscular power diminished, with wasting, contraction of tendons,
and all the signs of impaired nutrition. The nails become hard
and clawed; perforating ulcers of the feet are common; portions
of the extremities, including whole fingers and toes, die and drop
off. Later, paralysis becomes more marked, affecting the
muscles of the face and limbs. The disease runs a very chronic
course, and may last twenty or thirty years. Recovery occasionally
occurs. In the mixed form, which is probably the most
common, the symptoms described are combined in varying
degrees. Leprosy may be mistaken for syphilis, tuberculosis,
ainhum (an obscure disease affecting negroes, in which the little
toe drops off), and several affections of the skin. Diagnosis is
established by the presence of the bacillus leprae in the nodules
or bullae, and by the signs of nerve degeneration exhibited in
the anaesthetic patches of skin and the thickened nerve trunks.
In former times leprosy was often confounded with other skin diseases, especially psoriasis and leucoderma; the white leprosy of the Old Testament was probably a form of the latter. But there is no doubt that true leprosy has existed from time immemorial. Prescriptions for treating it have been found in Egypt, to which a date of about 4600 B.C. is assigned. The disease is described by Aristotle and by later Greek writers, but not by Hippocrates, though leprosy derives its name from his “lepra” or “scaly” disease, which was no doubt psoriasis. In ancient times it was widely prevalent throughout Asia as well as in Egypt, and among the Greeks and Romans. In the middle ages it became extensively diffused in Europe, and in some countries—France, England, Germany and Spain—every considerable town had its leper-house, in which the patients were segregated. The total number of such houses has been reckoned at 19,000. The earliest one in England was established at Canterbury in 1096, and the latest at Highgate in 1472. At one time there were at least 95 religious hospitals for lepers in Great Britain and 14 in Ireland (Sir James Simpson). During the 15th century the disease underwent a remarkable diminution. It practically disappeared in the civilized parts of Europe, and the leper-houses were given up. It is a singular fact that this diminution was coincident with the great extension of syphilis (see Prostitution). The general disappearance of leprosy at this time is the more unintelligible because it did not take effect everywhere. In Scotland the disease lingered until the 19th century, and in some other parts it has never died out at all. At the present time it still exists in Norway, Iceland, along the shores of the Baltic, in South Russia, Greece, Turkey, several Mediterranean islands, the Riviera, Spain and Portugal. Isolated cases occasionally occur elsewhere, but they are usually imported. The Teutonic races seem to be especially free from the taint. Leper asylums are maintained in Norway and at two or three places in the Baltic, San Remo, Cyprus, Constantinople, Alicante and Lisbon. Except in Spain, where some increase has taken place, the disease is dying out. The number of lepers in Norway was 3000 in 1856, but has now dwindled to a few hundreds. They are no longer numerous in any part of Europe. On the other hand, leprosy prevails extensively throughout Asia, from the Mediterranean to Japan, and from Arabia to Siberia. It is also found in nearly all parts of Africa, particularly on the east and west coasts near the equator. In South Africa it has greatly increased, and attacks the Dutch as well as natives. Leper asylums have been established at Robben Island near Cape Town, and in Tembuland. In Australia, where it was introduced by Chinese, it has also spread to Europeans. In New Zealand the Maoris are affected; but the amount of leprosy is not large in either country. A much more remarkable case is that of the Hawaiian Islands, where the disease is believed to have been imported by Chinese. It was unknown before 1848, but in 1866 the number of lepers had risen to 230 and in 1882 to 4000 (Liveing). All attempts to stop it by segregating lepers in the settlement of Molokai appear to have been fruitless. In the West Indies and on the American continent, again, leprosy has a wide distribution. It is found in nearly all parts of South and Central America, and in certain parts of North America—namely, Louisiana, California (among Chinese), Minnesota, Wisconsin and North and South Dakota (Norwegians), New Brunswick (French Canadians).
It is difficult to find any explanation of the geographical distribution and behaviour of leprosy. It seems to affect islands and the sea-coast more than the interior, and to some extent this gives colour to the old belief that it is caused or fostered by a fish diet, which has been revived by Mr Jonathan Hutchinson, but is not generally accepted. Leprosy is found in interiors where fish is not an article of diet. Climate, again, has obviously little, if any, influence. The theory of heredity is equally at fault, whether it be applied to account for the spread of the disease by transmission or for its disappearance by the elimination of susceptible persons. The latter is the manner in which heredity might be expected to act, if at all, for lepers are remarkably sterile. But we see the disease persisting among the Eastern races, who have been continuously exposed to its selective influence from the earliest times, while it has disappeared among the Europeans, who were affected very much later. The opposite theory of hereditary transmission from parents to offspring is also at variance with many observed facts. Leprosy is very rarely congenital, and no cases have occurred among the descendants to the third generation of 160 Norwegian lepers settled in the United States. Again, if hereditary transmission were an effective influence, the disease could hardly have died down so rapidly as it did in Europe in the 15th century. Then we have the theory of contagion. There is no doubt that human beings are inoculable with leprosy, and that the disease may be communicated by close contact. Cases have been recorded which prove it conclusively; for instance, that of a man who had never been out of the British islands, but developed leprosy after sharing for a time the bed and clothes of his brother, who had contracted the disease in the West Indies. Some of the facts noted, such as the extensive dissemination of the disease in Europe during the middle ages, and its subsequent rapid decline, suggest the existence of some unknown epidemic factor. Poverty and insanitation are said to go with the prevalence of leprosy, but they go with every malady, and there is nothing to show that they have any special influence. Vaccination has been blamed for spreading it, and a few cases of communication by arm-to-arm inoculation are recorded. The influence of this
