PELLAGRA 329 



DISEASES OF UNCERTAIN ^ETIOLOGY. 



PELLAGRA. 



(Pellagra — rough skin; " pelle," the Italian word for skin, " agra " 

 meaning rough.) 



DEFINITION. 



A chronic endemic disease of unknown causation with cutaneous, 

 gastro-intestinal and nervous symptoms which usually recur in the 

 spring and autumn. 



DISTRIBUTION. 



Perhaps Francis of Assisi suffered from it. 



It was well known by medical men to be widespread in Italy at the 

 beginning of the eighteenth century. 



Casal discovered it in Spain in 1735. 



Also present in Portugal and France. 



Some of Napoleon's soldiers became infected in Italy. 



It is still very prevalent in Austria and Hungary. 



Roumania has 200,000 cases (Babes). 



Reported in the British Isles in i860. In Scotland and the Shet- 

 lands in 1909. 



It is also found in Egypt, West Indies, Mexico, North American 

 Indians, India, Straits Settlements, Philippine and Sandwich Islands; 

 Africa, Europe, Asia, Oceania, America, and perhaps is world-wide. 



It is found chieflv in country places and along- certain streams, less 

 seldom in towns. 



Attacks most frequently appear during the late springtime and the 

 autumn. It tends to disappear in the winter. 



None are exempt. Females are attacked to males as two is to five. 



Jews are rarely affected. 



It is tO' be noted that those engaged in agriculture appear to be 

 affected most. 



ETIOLOGY. 



The chief theories are : — 

 (i) The Deficiency Theory. 



(2) The Maize Theory. 



(3) The Parasitic Theory. 



(4) The Mineral Acidosis Theory. 



(1) The Deficiency Theory. 



The lack of some nitrogenous complex in the food. 



When steam-milled mealie bread alone w^as supplied to prisoners 



