SYMPTOM A TO LOGY 



1721 



may be intact, those passing through the cells disappear. A perivascular 

 infiltration around the vessels of the brain has been described by sortie authors, 

 but was not present in our specimens nor in those described by Mott. There 

 is also an increase in the neuroglia tissue in our specimens, but there is 

 no cellular infiltration into grey or white matter, or any sign of acute 

 inflammation. 



The cerebro -spinal fluid is usually present in considerable quantity, and 

 exhibits a medium amount of tension. It is alkaline, specific gravity varying 

 from about 1004 to 1007; it generally gives reactions indicating the presence 

 of some protein and butyric acid, and it generally reduces copper sulphate. 

 The number of cells per cubic millimetre varies, but is about thirty-five, 

 according to Hindman, whose differential count is: Small lymphocytes, 

 36'3 per cent.; polymorphonuclears, i8'6 per cent.; large mononuclears, 

 19*2 per cent.; plasma cells, 7 per cent.; lymphocytes, 5'i per cent. The 

 liquor is sterile, and injections into rabbits have been negative. 



The skin has been reinvestigated by the Illinois Commission, who find 

 that the changes can be described as due to an angio-neurotic process. 

 There is infiltration of the true skin, and especially the pars papillaris, and 

 oedema of the connective tissue. The rete Malpighii is infiltrated with cells, 

 but otherwise normal. The stratum granulosum is normal, but the stratum 

 corneum is thickened, and shows parakeratosis. 



In the blood there is a reduction in the numbers of the red cells, which 

 usually appear quite normal. There is mononucleosis, and Low has described 

 granules in the mononuclear leucocytes, which, however, he has also found in 

 other diseases. Fatty degeneration and cloudy swelling have been recorded 

 in the liver, but no constant changes have so far been found in the spleen. 



Symptomatology. — The incubation period of pellagra is unknown, 

 but it cannot be of long duration, as we have known it to occur in 

 a child three months of age, and, as we have already advanced 

 arguments against heredity, this case is in favour of a short incubation 

 period. We have also met with a case in which the skin symptoms 

 are said to have appeared about two weeks after return from a 

 visit to a pellagrous area in a person who was said to have always 

 lived in a non-pellagrous area. We are always very sceptical of 

 these histories, and should not have mentioned it if it had not 

 curiously coincided with the case recorded by Sambon, where he 

 states that a child born in an Italian gaol was nursed by its own 

 mother in gaol until five months old, and then sent to some peasants 

 living in a pellagrous area, when it developed pellagra in two 

 weeks. 



The description of a typical case is something of this nature: — 

 A person, male or female, young or old, in apparently excellent 

 health or in bad health, living or working in the sunshine of a 

 spring day, notices that a sunburn appears on the backs of his 

 hands, and perhaps the dorsa of his feet, if bare, and more rarely, 

 also, on his face or neck. He thinks little of it, though the in- 

 flamed area burns, and may even blister. Perhaps he has a sore 

 mouth, and perhaps he has a little diarrhoea or constipation. 

 Perhaps he feels a little giddy in the morning, and perhaps he is 

 easily tired. In a week or so the redness dies down, and the 

 affected area is seen to be pigmented, and perhaps to have the skin 

 thickened in places. In the course of a few days, or a week or 

 so, these thickened areas desquamate, and the skin underneath 



