Although the main reliance in the recognition of the disease, the eruption of pellagra, not infrequently is very tardy in making its appearance, while, until it appears, it is ordinarily impossible to determine the presence or absence of the disease with certainty, a shrewd suspicion may, nevertheless, be formed from a careful consideration of the other symptoms. This applies only to a limited extent to children, in most of whom the manifestations of the disease, other than the eruption, are slight and frequently difficult or impossible to make out. It has happened more than once that the liveliest of a group of children was found with a well-developed eruption. Notwithstanding this, however, careful questioning of the mother, if she be observant, not infrequently develops the fact that the child seems to her less active than common; in some cases it is evidently listless and fretful and the mother may also recognise that it has fallen off in weight. In older individuals a complaint of loss of strength with indigestion or nervousness, or both, coming on or made worse in the spring or summer and improving in the fall and winter, are very frequently met with.

The patient will complain of being " worked out," of having "blind staggers" (disriness, vertigo), of discomfort or pain in the pit of the stomach, frequently of headache, sometimes of wakefulness, frequently also of sluggishness of the bowels, requiring the habitual use of medicine to move them. Although, as has already been said, these symptoms alone or even with the addition of such symptoms as a burning or scalded feeling of the mouth, reddened tongue, burning of the hands or feet and loose bowels are not enough to distinguish pellagra from other conditions, they are ample to justify a suspicion of the disease, especially if such individual is known to be finicky or a nibbler about food, or has been living on a diet made up largely of biscuits, corn bread, grits, gravy, and sirup, with little or no milk or lean meat; in other words, on a diet mainly of cereals, starches, and fat, with but little, if any, of the animal flesh (protein) foods.

As the disease progresses the patient loses strength and flesh, the skin shrivels and the bones become prominent. The muscles waste and the movements are slow and languid. The nervous symptoms consist first in a melancholia, later the delirium may become maniacal in character; twitchings, tremors or epileptic seisures are frequently seen.

Boyd,5 discussing the disease as it appeared among the Turkish prisoners in Egypt, states that the first symptoms appeared to be loss of appetite, followed by failure of hydrochloric acid, failure of pancreatic juice, failure to assimilate, decomposition of protein, and finally excretion of indican. There was also severe loss by diarrhoea. Metabolic observations were made upon Turks who did not show these symptoms, and it was found that their excretion of fat and protein were both well above the normal, showing that they were already in what might be called a pre-pellagrous state.5a.

5 Boyd, Roy. Soc. Med. Sec. Ther. and Parm. Nov. 1910, Lane. 1919, ii, 979.

Lewis6 reports that the chemical composition of the blood of pellagrins shows no abnormal deviations, but degenerative changes have been observed in the tissue7 and in the cells of the sympathetic nervous system.8

According to Nicolaidi,9 a comparison of analyses of feces, urine, and food of pellagra patients shows that considerable demineralisation occurs in the organism; there is a pronounced decrease in the amount of nitrogen, phosphates, magnesia, lime, and potash excreted in the urine and a surprising increase in the amount eliminated in the feces. Comparative experiments with patients suffering from other similar affections showed that this derangement of absorption is quite characteristic for pellagra. Hunter, Givens and Lewis10 found, however, that pellagrins have no difficulty in maintaining nitrogen balance even on moderate amounts of protein in the food.

Sullivan, Stanton, and Dawson11 state that the mineral metabolism of pellagrins seems to be abnormal, especially in the actively pellagrous state, as instanced by the low phosphorus excretion, despite the fact that the diet taken at the tiqie of the observations was generally one with abundance of milk. There were indications of heightened putrefaction in the intestines, and casts or albumen or both in the urine gave evidence of more or less kidney change in about 50 per cent of the cases, although marked pellagra can occur with no evidence of kidney change. They observed low excretion of total nitrogen and ordinary urinary constituents. The urea ration in general was low, and in certain cases with fair total nitrogen the urea ratio was lower than should be expected, a finding which suggests liver insufficiency. The low excretion of uric acid and creatinin during the active stages of the disease shows a low level of metabolism. The utilization of protein was found to be subnormal, even after several weeks of remedial diet.

5a Various theories regarding the cause of pellagra are reviewed by Vi-swalingam (J. Trop. Med. Hyg. ax, 153, 1918; 33, 46, 1020; Expt. Sta. Record 43, 263). Further evidence is given in confirmation of the view that both the deficiency and the parasite theory hold good in the etiology of the disease among the Chinese in the Malay States. The freedom of the Malay and Tamil laborers from the disease is thought to be due chiefly to the better quality of their diet, which includes a variety of fresh vegetables and more or less meat. That faulty diet is not solely responsible for the disease is shown by the seasonal recurrences of symptoms in patients placed in a hospital with adequate diets for considerable periods of time. " Whether the infecting agent is an organism which enters the gastro-intestinal system and produces a toxin which gets absorbed into the system and produces the varied symptomatology, or whether owing to a deficiency in the vitamins some deleterious products are created in the intestines and give rise to an intoxication of the system, it if difficult to say at present".

6 Lewis, Hyg. Lab. Bull. 116, p. 37, 1920.

7 Sundwall, U. 8. Pub. Health Bull. 106, 5, 1917.

8 Roof, Roy. 80c. Med. Sect. Ther. and Pharm. Nov. 1919; Lane. 1919, ii, 979. See also Vedder, 3rd Rep. Thompson, Pell. Com. p. 340; Roberts, Pellagra, St. Louis, 1912; Wood, Treatise on Pellagra, New York, 1912; Pollock and Singer, Arch. Int. Med. 11, 565, 1913.

9 Nicolaidi, Zentr. Bioch. Biophys. 15, 815; 16, 676. 10 Hunter, Givens, and Lewis, Hyg. Lab. Bull. 102.

11 Sullivan, Stanton, and Dawson, Arch. Int. Med 27, 387, 1921.