SCURVY, BERIBERI, AND PELLAGRA Scurvy is an acute or chronic disease char acterized by debility, mental apathy and anemia, with spongi ness of the gums and ulcerations of the mouth, manifesting a tendency to hemorrhages into the subcutaneous tissues and from the mucous surface.
(b) Beriberi is an acute or chronic disease characterized by changes in the nervous system, and particularly by a multiple peripheral neuritis, with an especial tendency to attack the nerves of the limbs, the pneumogastrics and the phrenics, with varying degrees of cardiac disturbances, oedema, serous effu sions and gastro-intestinal derangements.
(c) Pellagra is an acute or chronic disease characterized by a peculiar erythema and dermatitis on those parts of the body exposed to the sun's rays, by salivation, dyspepsia, and diarr hoea, and by nervous manifestations which may terminate in mental disturbances and paralysis.
Geographic general one may say that they are world wide, though varying in their relative prevalence, as shown in the following table which indicates their greatest in cidence.
Incidence.—They may occur either as sporadic cases or in a wholesale prevalence simulating epidemic or endemic distribu tion. Such latter instances usually occur among closely cir cumscribed groups of people, such as soldiers at military posts or on campaigns, laborers at labor camps, exploring parties, sailors on long cruises, inmates of jails, penitentaries, insane hospitals and other similar institutions.
Past Ideas of Etiology.—Widely different theories of their etiology have been held until recently and these we shall briefly review before passing to current knowledge.
(a) Scurvy has been variously ascribed to : (1) a deficiency of potassium in the blood; (2) a decreased alkalinity of the blood, i.e., an acidosis; (3) to ptomaine poisoning; and (4) to a specific infection.
(b) Beriberi has been ascribed to; (t) poisoning by arsenic or by oxalates; (2) to a deficiency of nitrogen, fat or phos phorous; (3) a specific infection; or (4) as an unknown intoxica tion.
(c) Pellagra has been-variously regarded as: (1) an intoxica tion due to the consumption of spoiled corn; (2) as a specific infection, either transmitted by contact or by the agency of the small black flies of the genus Simu/ium; or as an intoxication due to colloidal silica.
Some few perhaps still adhere to some of the foregoing views, but in general we believe that the majority of scientific men regard these diseases as having the following etiology.
Present Views of Etiology.—(a) Scurvy (Hoist and Frolich) is found to be due to a deficiency of some essential constituent from preserved foods but which is present in all kinds of fresh food, both animal and vegetable.
(b) Beriberi (Fraser and Stanton, Vedder, et al) is due to the removal in the process of milling and polishing rice or wheat, of certain substances present in the pericarp of the grain, which are necessary to life (Figs. 95, 96, 97, 98). About i gm. of this substance is present in one kilogram of rice and it may be extracted from rice millings by alcohol. By its employment dry beriberi and experimental polyneuritis of fowls may be cured.
(c) Pellagra (Goldberger and Wheeler) is due to a diet devoid of meats or vegetable fats. It has been produced in 6 of II convicts by a five months diet of biscuits, cornbread, collards, grits, rice, fried mush, brown gravy, sweet potatoes, cabbage and cane syrup. Some are inclined to dispute the correctness of the diagnosis of pellagra among the subjects in this experi ment.
Vitamins or Accessory Food Factors.—Based upon the dis covery of the therapeutic value of rice milling extracts in the cure of beriberi, these diseases have been ascribed to the ab sence of minute quantities of certain substances from the diet. Recent researches by Funk, McCallum and others have so far resulted in the recognition of two of these substances in food stuffs, one of which is soluble in water, the other in fats. Their chemical nature is unknown. These are also designated fac tors B and A respectively. The beriberi vitamin or antineuritic factor is identified with the water soluble factor B. Both of these are experimentally found to be essential for growth and maintenance. From the known relationship of scurvy to preserved foods, a third vitamin, an antiscorbutic factor, is assumed to exist in fresh vegetable food. To fat soluble A are attributed antirachitic properties. Thus in addition to possessing a knowledge of the protein, carbohydrate and fat content of a dietary, it is also necessary to consider its content of vitamines or accessory food factors. The utilization of these substances in the body is not certainly known, but Green con siders their main functions concern the gross metabolism of food, probably principally in oxidative catabolism.