2242 



DYSIDROSES AND DYSTROPHIES 



plantar fold, which deepens and extends until it encircles the toe, 

 which is finally severed from the foot. 



History. — The disease was first described by Da Silva Lima in 1852. 

 Clarke, in i860, in his description of the Gold Coast, drew attention 

 to a dry gangrene of the little toe found in negroes in that region, 

 and considered it to be a manifestation of yaws. In 1867 Da Silva 

 Lima further studied the disease, and with Wucherer described 

 fifty cases of it in Brazil, and introduced the term ' ainhum ' ; in the 

 same year CoUas wrote an account of the disease. Da Silva Lipia 

 ventured no explanation of the disease. In 1873 Crombie described 

 the disease as occurring in India; in 1876 Pirovano found it in 

 Buenos Ayres; and in 1877 Corre mentions it in Reunion. 



It is reported in the West Indies by Potoppidian in 1879; in 

 North Carohna by Hornaday and Pitman in 1881; in Nossi-Be by 

 Deblenne in 1883; in Western Virginia by Duhring in 1884. This 

 last observer, along with Wile, studied the disease microscopically, 

 considering the essential pathological feature to be an inflammatory 

 oedema of the hypodermis. In 1886 Eyles wrote an excellent 

 account of the pathological histology of the disease as seen in the 

 Gold Coast, concluding that irritation caused an internal prolifera- 

 tion of the epithelium, which, extending into the cutis, damaged 

 the vasomotor nerves, leading to a spasm of the vessels, endarteritis 

 obliterans, fibrosis of the cutis, and rarefying osteitis, whereby the 

 digit is separated from the foot. After this date there are a number 

 of papers, among which may be specially mentioned those by 

 Moriera, Dalgetty, and Maxwell in 1900, Muir in 1903, Ashley- 

 Emile in 1905, and Egas Moniz de Aragao in 1910. 



Climatology.- — The disease is known in South America, espe- 

 cially in Brazil and the Argentina, and also in British Guiana; in 

 North America, especially in the Southern United States, but also," 

 though rarely, in the Northern, and in Canada. It also occurs in 

 the West Indies. In Africa it is especially well known on the West 

 Coast, and particularly in the Gold Coast, but it also occurs in 

 Algeria, Egypt, Sudan, East Africa, Madagascar, and the Transvaal. 

 In Asia it is known in India, China (?), and Ceylon. It also occurs 

 in Polynesia. We have seen a case in an Italian peasant. 



etiology. — The causation of the disease is not known. The 

 theories suggesting that the disease is due to leprosy, wearing rings, 

 or other tight bands, self-mutilation, may be dismissed at once, as 

 there is nothing to support them. .j 



According to some authorities — Le Dantec, Da Silva Lima, etc. 

 — the hereditary factor has a certain importance. Da Silva Lima 

 quotes the example of a negro family all the members of which 

 presented the condition. 



The racial factor has also been given much prominence, for the 

 condition practically occurs only among natives and mulattoes. 



Zambacho Pasha, Eyles, and Moreira, are, in our opinion, correct 

 in their view that the reason why the native races are attacked is 

 because they walk barefoot, and that irritation or injury to the 



