Definition:—A chronic disease, infectious in character, caused by the bacillus leprae, a micro-organism of great vitality and persistence, but of feeble activity, discovered by Hansen in 1871. The disease is characterized by the appearance in the skin, mucous membranes, and occasionally in the viscera, of tubercular masses (tubercular leprosy), or by a similar involvement of the structure of the nerves (anaesthetic leprosy). The changes in the nerves and in other structures are at first separate, but ultimately they intermingle until no distinction can be made.

Symptomatology:—The disease attacks all alike who have been brought persistently into contact with the infection. It seldom occurs in patients under six years of age and is most common in individuals between the ages of twenty and forty years. The course of the development is protracted usually three or four years. At first there are symptoms of acute illness, as chilliness, fever, anorexia, general depression, dulness or drowsiness and feebleness, resembling the symptoms that occur in syphilis preceding the eruption.

With malaise there are severe aching pains in the head and also in the joints, with epistaxis and occasionally exhausting sweats. This condition may continue irregularly for months before eruption appears. In the tubercular form, which attacks the skin and mucous membranes, at first there are patches or macules, which are hyperaesthetic and pigmented. Ultimately the sensitiveness disappears, as well as the color, the skin assuming the appearance of distinctly circumscribed white patches. The nodules appear on the face and in the structure of the ears, as hard, flattened masses, movable and distinct, without sensitiveness. There is an increase in the growth of the skin, which ultimately forms into folds or masses, which has classed the disease in the past as one form of elephantiasis. The nodules increase until the entire surface of the body may be covered. The space between the nodules may be white and smooth, while the nodules themselves will break down and ulcerate, producing an offensive distortion, characteristic of this disease.

During the development of the macular stage of this disease, a neuritis develops, which, at first, produces extreme sensitiveness. Ultimately the nerve function is destroyed and sensation is absent. Eruptions occur along the course of the nerves, which result in extensive destruction of tissue, and final loss of the smaller extremities, beginning with the tips of the fingers and toes. Atrophy of both the muscles and skin occurs, later on producing much deformity and mutilation.

Prognosis:—This disease has always been considered incurable. Notwithstanding the persistent study during the last few years but little advancement has been made in a knowledge of the methods of cure; however, there are cases which have recovered. Spontanous recovery has been known to occur among those who were isolated, and, more recently, positive claims have been made by experimenters to cures of a satisfactory and permanent character. Many cases develop so slowly that the patient enjoys reasonable health, and is able to accomplish an average amount of work for a number of years before sufficient deformity or mutilation occurs to effectually incapacitate him.

Treatment:—The systematic isolation or segregation of lepers has been practiced in many countries for years. The object has been the prevention of the spread of the disease, more than the cure of those segregated. In many countries no measures are taken for the improvement of these patients, they being left to care for themselves. In other cases they are provided with comfortable and hygienic surroundings and with proper food, after they become unable to care for themselves.

In 1888 Unna published articles advising a method of cure, which received his name. This consisted of painting the affected parts with pyrogallic and chrysarobic acids, and applying a plaster-mull which is composed of a combination of creosote and salicylic acid. The patient was given ichthyol internally. The same year extensive observations were made concerning the use of chaulmoogra oil. This was given internally in dram doses, and very satisfactory results were said to have been obtained. In some cases it was administered hypodermically. Gurjun balsam was also used about the same time, and good results were claimed. The use of gynocardic acid externally and the internal use of the oil of gynocardium have produced satisfactory results in a few cases. We would advise that the persistent external and internal use of echinacea be made in order to observe its influence. It should be beneficial. Claims of benefit from the use of calotropis gigantea in this disease, and also for hoang nan and kava kava have been made but are not substantiated.

The Eclectic Practice of Medicine with especial reference to the Treatment of Disease, 1910, was written by Finley Ellingwood, M.D.