CHAPTER XI. 

 LEPROSY. 



Leprosy is a disease of great interest, alike in its clinical and 

 pathological aspects; whilst from the bacteriological point of 

 view also, it presents some striking peculiarities. The invariable 

 association of large numbers of characteristic bacilli with all 

 leprous lesions is a well-established fact, and yet, so far, at- 

 tempts to cultivate the bacilli outside the body, or to produce 

 the disease experimentally in animals, have been attended with 

 failure. Leprosy, so far as is known, is a disease which is con- 

 fined to the human subject, but it has a very wide geographical 

 distribution. It occurs in certain parts of Europe — Norway, 

 Russia, Greece, etc., but is commonest in Asia, occurring in 

 Syria, Persia, etc. It is prevalent in Africa, being especially 

 found along the coast, in the Pacific Islands, in the warmer 

 parts of North and South America, and also to a small extent 

 in the northern part of North America. In all these various 

 regions the disease presents the same general features, and 

 the study of its pathological and bacteriological characters, 

 wherever such has been carried on, has yielded similar results. 



Pathological Changes. — Leprosyis characteristically a chronic 

 disease, in which there is a great amount of tissue change, with 

 comparatively little necessary impairment of the general health. 

 In other words, the local effects of the bacilli are well marked, 

 often extreme, whilst the toxic phenomena are proportionately at 

 a minimum. 



There are two chief forms of leprosy. The one, usually 

 called the tubercular form, — lepra tuberosa or tuberculosa, — is 

 characterised by the growth of granulation tissue in a nodular 

 form or as a diffuse infiltration in the skin, in mucous mem- 

 branes, etc., great disfigurement often resulting. In the other 

 form, the anaesthetic, — maculo-anaesthetic of Hansen and Looft, 

 — the outstanding changes are in the nerves, with consequent 

 anaesthesia, paralysis of muscles, and trophic disturbances. 



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