Synonyms.—Lepra; Elephantiasis Graecorum; Leontiasis.

Definition.—A chronic infectious disease, caused by the bacillus leprae, and characterized by cutaneous pigment alterations, tuberculous growths in the skin and mucous membranes, and by degenerative changes in the nerves, with implication of the lymphatic ganglia and internal viscera, and the ultimate production of a cachexia, which usually terminates fatally.

History.—Leprosy existed in Egypt 3500 B. C., and the clear-cut and well-defined description of the disease and the methods of dealing with it, as found in the thirteenth and fourteenth chapters of Leviticus, show that the writer was as familiar with it as the authors of modern times. Lucretius says, "Leprosy is a disease born in Egypt along the waters of the Nile, and nowhere else." The Hebrews brought it with them from the land of bondage, and to be a leper was worse than death.

India, Arabia, Palestine, and China have also been its home from the earliest times. During the decline of the Roman Empire, when Europe was overrun with immigration, leprosy increased to an alarming extent. Rev. L. W. Mulhane, in a little work on "Leprosy and the Charity of the Church," says: "In the thirteenth and fourteenth centuries, the awful disease had made such headway that leper institutions might be said to cover the face of Europe, and at one time there was scarcely a town in France but had its leper asylum, and in the kingdom of France alone there were two thousand leproseries—hospitals for lepers.

"In England one hundred and ten leper-houses existed from the twelfth to the sixteenth century."

The twentieth century finds the disease intrenched in Norway, Egypt, Syria, India, China, Japan, the West Indies, South America, the Philippines, and the Sandwich Islands. Not a single country in Europe is free from it, and in the United States there are more than five hundred cases.

The importation of leprosy into the United States may be traced to several distinct sources. Dr. Prince Morrow in "The Twentieth Century Practice," says:

"1. It was introduced into the Atlantic Coast cities and the countries along the Atlantic seaboard from the West Indies, and probably Africa, through the importation of slaves, and intercourse through travel and trade with the neighboring West India Islands.

"2. By leprous immigrants from Norway and Sweden into the Scandinavian colonies of Minnesota, Wisconsin, Iowa, and Dakota.

"3. By the Acadian refugees from the British Provinces of New Brunswick into Louisiana.

"4. By lepers from Mexico into Texas and States bordering the Gulf of Mexico and the Rio Grande.

"5. By Chinese immigrants into San Francisco and elsewhere on the Pacific Coast.

"6. By Hawaiian lepers into California, Utah, and other parts of the country."

Etiology.—While all ages, conditions, and sexes are susceptible to the disease, the period between twenty and thirty years of age is the most liable to attack, and must be given as among the predisposing causes. It is somewhat more common in men than in women, and while all classes of society are susceptible, squalor and overcrowding, which give greater exposure to contagion, favor the disease. Heredity has also undoubtedly some influence.

The specific cause, the bacillus leprae, discovered by Hansen in 1874, resembles the tubercle bacillus, though it may be distinguished from it by "differential stains," by their great number, and by their tendency to form colonies, and to the fact that as yet it has failed to propagate in inoculation tests.

Pathology.—The tubercles of leprosy are made up of granulomatous tissue, and consist principally of round cells, in and between which are found the bacilli in large numbers. These tubercular masses involve the skin, and, pushing outward, form nodular masses, between which are seen areas of ulceration and cicatrization, which, in the face, distort the features, and give rise to the so-called facies leonina.

These tubercular masses caseate, soften, and discharge a thick purulent material, or partial organization may take place, staying the further progress of the disease.

The destruction of tissue proceeds gradually, years being occupied in destroying the patient. The deep, ulcerative process may amputate fingers and toes in its progressive march—lepra mutilans. When the bacilli develop in the nerve fibers and their sheaths, a peripheral neuritis results, with local anesthesia.

Symptoms.—This is a chronic disease, lasting from five to twenty years before death finally ends what has been, for years, a living death. Indefinite prodromal symptoms, such as malaise, general depression, loss of appetite, gastro-intestinal disturbance, may appear months before the outbreak. Two distinct forms are seen: 1. The nodular, or tubercular; 2. The anesthetic.

Tubercular Form.—This is the most common form, embracing from sixty to seventy per cent of all cases. The first suspicious or positive evidence is the appearance of irregular spots or patches of erythema, more or less clearly defined and slightly hyperesthetic. These always appear on the face, though other portions of the body may be involved. After a time, these may partially or wholly disappear for a season, but always reappear, generally as circumscribed infiltrated spots. Gradually these develop into leprous nodules. The nose and lips become thickened and stiff.

These same tubercular masses appear in the nose, mouth, and throat; the voice becomes hoarse, and may finally disappear. The hair on the face, such as the eyelashes and eyebrows, drop out, the patient presenting a horrible appearance. Sometimes these infiltrated patches fail to develop into tubercular nodules, but gradually change to smooth, white patches—lepra alba.

The tubercular nodules, after developing gradually for years, undergo retrogressive changes, the tumors gradually melting away, leaving in their place dark, pigmented patches. In this way, bone and cartilage may be destroyed without ulceration.

Generally, however, indolent ulcers develop, which result in great destruction of tissue; the nose, fingers, toes, and sometimes an entire limb, are amputated by this method. Tubercles may develop on the cornea and iris, destroying the sight, and the patient, blind and with face horribly distorted, with nose, fingers, and toes rotting off, presents a condition unequaled in any other disease.

Anesthetic Form.—So different in character is this form of leprosy, that it is difficult to realize that it arises from the same specific cause.

The first evidence of the disease is the appearance, usually, of a local erythema, though in rare cases its first appearance is in the form of bullae; so constant are the macules in this variety that Hansen proposed the term "macular leprosy" for that of anesthetic leprosy.

This variety is characterized by nerve lesions and trophic changes in the skin. With the appearance of the macules, which may be of a coppery hue or a pale yellow, there is a stinging, burning, or painful sensation. These appear on the shoulders, back, buttocks, knees, face, and arms, and vary in size from a dime to quite a large patch.

At first painful, it soon loses its sensibility, which is characteristic of this form. The nerve trunks affected, if superficial, can be readily felt as hard, nodular substances. Bullae occasionally appear, leaving anesthetic patches behind; with these changes, go atrophy and contraction of the muscles.

The hands become clawed, there is wrist-drop, the face is deformed, the eyelids and mouth can not be closed, and the tears and saliva flow away; the nails split, change color, and fall off; the hair loses its gloss, and falls out; the strength gradually fails, and, after many long years, death, the leper's friend, comes to his relief.

Diagnosis.—In the early stages, the erythematous macule, with hyperesthesia, followed by anesthetic areas, is quite characteristic. In the advanced stage there would be little difficulty in recognizing either form. When there is doubt, a microscopic examination will reveal the bacillus lepra, if the disease be present, for it is known to be found in no other disease.

Prognosis.—The disease, though terminating fatally, may run for several years without very much suffering or discomfort. The profession has, as yet, looked in vain for a specific for this dread disease; hence the prognosis is almost certain death.

Treatment.—The experience of thirty-five centuries of treatment is not flattering to the profession. Of the large number of agents used, none have stood the test, and the physician of the twentieth century stands as helpless in its presence as the Egyptian healer, who practiced his art fifteen hundred years before Christ.

The medical world is anxiously awaiting the verdict of the latest remedies said to be curative; namely, chaulmoogra oil, expressed from the seeds of the Gynocardia odorata. Dr. Le Page, of Calcutta, was the first to use the remedy, which is given in doses of from five to eighty drops three times a day, either in capsules or in emulsion. The patients do better on the large dose; but, unfortunately, the agent is irritant to many stomachs, and even the minimum dose can not be retained. It is also used externally in the proportion of one part to five or ten parts of olive or cocoanut oil, or as an ointment of gynocardic acid.

Gurjun oil, derived from the Dipterocarpus turbinatus, is also another agent of which great things are expected. This is given in emulsion, equal parts of the oil and lime-water, the dose of which is from one to four drams; externally, one part to three of olive oil or lime-water.

Since the disease, when once contracted, is incurable, the greatest interest is attached to the problem of how to avoid getting the disease. This is of special interest to Americans in view of the recent acquisition of Hawaii, Puerto Rico, and the Philippines, each of which is the habitat of leprosy.

Isolation or segregation of lepers is perhaps the first and most important of all prophylactic means, and an "International Congress," such as met in Berlin in October, 1897, should receive the hearty co-operation of all medical men. The adoption of uniform laws among all the nations of the world, as to the establishment of lazarettos and the compulsory isolation of lepers, would go far to banishing the disease. To this should be added the improvement in the social and hygienic condition of the people.

The Eclectic Practice of Medicine, 1907, was written by Rolla L. Thomas, M. S., M. D.