Pellagra is a disease of obscure origin, associated with faulty nutrition, which involves the nervous and digestive systems and the skin. Usually one of the first symptoms is soreness and inflammation of the mouth, then a remarkable, symmetrical eruption appears on parts of the body, which, with weakness, nervousness and indigestion form the most characteristic picture of the disease.
There are some indications that infection may be the immediate cause, but the strong evidence is that a faulty diet is the chief predisposing cause of the disease. Certain it is that pellagra is both prevented and cured by a diet containing liberal amounts of milk, eggs and leafy vegetables. On the other hand, those who live during the winter months on a diet chiefly derived from bolted white flour, degerminated cornmeal, polished rice, starch, sugar, molasses and fat pork, furnish the victims of this dreaded disease in the spring.
Pellagra was discovered in Northern Spain, by Cassal, in 1735, but for many years it had been of common occurrence in parts of Italy, and during the last century has been prevalent in parts of France, the Balkans, especially Roumania, and for a lesser time, in Egypt. In America the disease was not recognized with certainty until 1908, but from that year its incidence apparently increased, until by 1917 there were 170,000 cases of pellagra recorded in the United States, principally located in the Southern States.
In 1914, Dr. Joseph Goldberger, of the United States Public Health Service, began an investigation of the factors concerned in causing pellagra. After he had studied its prevalence in various orphanages in the South, and had relieved the situation by improving the diet with milk, fresh vegetables and meat, he was anxious to know whether the disease could be produced by a faulty dietary, of the type common among pellagrins. He planned an experiment to this end, which would restrict men to a diet similar to that which had been supplied in the institutions where pellagra had been endemic, and where it had been relieved by the improvements in the food supply which have been mentioned. This type of diet was also very characteristic of that used in the homes of the cotton mill workers throughout the South, where pellagra was so common. The Governor of Mississippi offered pardon to any of the healthy white men in the state prison who would submit themselves as subjects for the experiment, and eleven actually underwent the test.
The men were put upon a diet consisting of articles made from white, wheat flour, degerminated cornmeal (maize), polished rice, starch, sugar, molasses, pork fat, sweet potatoes, coffee and very small quantities of collards and turnip greens—so small as to furnish inadequate protection against a certain degree of undernourishment. At the end of five and a half months six of the eleven men developed the skin lesions characteristic of incipient pellagra.
As a result of his investigations, Dr. Goldberger points out the important fact that when milk, eggs, meat, fresh fruit and vegetables are included in the diet, pellagra does not develop, also that the disease may be cured by giving these articles of food to the afflicted person.
Fig. 141.—Rachitic baby and normal baby of the same age, showing dwarfism and deformities caused by rickets. (By courtesy of Dr. Leonard Findlay, Glasgow, Scotland.)
Rickets. The actual cause of rickets is not definitely known, but the disease apparently results from wrong proportions between calcium and phosphorus, and to unfavorable amounts of these two substances in the food. Accordingly, it may be said to be due to a faulty diet—one which is rich in carbohydrates and poor in fats and possibly some substance as yet unrecognized—and it may be both prevented and cured by what is now regarded as suitable feeding.
The chief characteristics of the disease are arrested growth and softening of the bones, with dwarfism and deformities as a result. (Fig. [141].) It is essentially a disease of infancy, occurring as a rule, between the fourth and eighteenth months but some of its unfavorable effects, such as bone deformities and poor resistance to disease, may persist throughout life.