Greater Prevalence in Women.—Now that we attach no weight to insect transmission of pellagra we have only the debilitating effects of menstruation, pregnancy and lactation to explain the marked susceptibility shown by women of from seventeen to forty years of age. Before and beyond these ages the incidence in males and females is about the same.
Before Goldberger began his experiments he was struck by the relation poverty had to pellagra epidemiology, and as diet is the chief element differentiating poverty and affluence, he chose this line of research with the results recorded under etiology. His explanation of the greater incidence in adult females, especially wives and mothers, was their act of denying themselves the more desirable parts of the food.
Sandwith has noted the great frequency of pellagra in hookworm patients, thus of 300 such cases in Egypt, 46% had pellagra.
The Thompson-McFadden Commission was unable to note any evidence that would distinctly point to corn, good or bad, as giving rise to pellagra outbreaks. They did note, however, a very limited use of fresh meats.
Pathology and Morbid Anatomy
There is nothing very constant or characteristic in the pathological changes of pellagra. In the second stage the urine shows an indicanuria and the faeces an abundance of skatol. The examination of the gastric contents gives findings of anacidity and deficiency in pepsin. The HCl deficiency probably causes disturbance of pancreatic efficiency leading to mal-assimilation of fats and proteins.
The blood shows a moderate lymphocytosis but not an increase in the percentage of the large mononuclears as has been claimed by the adherents of the protozoon theory.
At autopsy we find rather marked emaciation. The wasting of all organs seems to be greater than in any other wasting disease. The skin lesions show degenerative changes in the corium with slight cellular infiltration. In the epidermis there is superficial atrophy but still some thickening in the stratum granulosum.
Warthin states that the lesions are those of a chronic intoxication. The spleen shows atrophy and in the follicles there is necrosis of germ cells as well as hyaline changes. The liver and kidneys often show fatty change. In general the changes are those of a senile character. There is atrophy of the mucosa of the small intestines and there may be small ulcers present.
The mesenteric glands are enlarged. Roaf has noted the presence of involvement of the adrenals and the Committee investigating pellagra in Turkish prisoners found a marked supra-renal inadequacy.