DIFFERENTIAL DIAGNOSIS— PROGNOSIS 



1731 



mentioned above, by the presence of the line of demarcation. In 

 biotripsis the skin is dry and wrinkled, and may be thickened 

 in places with dark-coloured patches, alternating wiih shining, 

 smooth, inelastic, atrophic areas; but this condition is by no means 

 limited to the hands or feet, but spreads up the arms and legs, and 

 is not visible on the face. 



It is hardly possible that Kaposi's disease (xerodermia pigment csa) 

 could be mistaken for pellagra, nor is ichthyosis likely to be con 

 founded with it. 



The wrinkled skin of the washerwoman's fingers is hardly hkely 

 to be confused with the chronic thickening found in pellagra, 

 though this disease is often found in women who wash clothes, and 

 who explain their own dermal condition in this way. 



Gastro-Intestinal Diseases.- — Of all the gastro-intestirial 

 diseases, sprue is the only one which in any way resembles pellagra, 

 which can be readily distinguished therefrom by the presence of 

 the skin eruption. It must, however, be remembered that the 

 psilosis linguae pigmentosse of West Indian writers is really pellagra. 



Attacks of diarrhoea or dysenteric-like attacks can only be recog- 

 nized as belonging to the syndrome of pellagra if the dermal signs 

 are present at the same time, or if they can be produced by exposure 

 to the sun, or if there is a very definite history of their previous 

 occurrence; unless, indeed, they are associated with marked 

 ptyalism or bilateral swelling of the parotid glands, or some other 

 symptom tending to indicate that pellagra was the cause. The 

 special cases in which diarrhoea and dysentery require careful 

 diagnosis are those in which they occur in lunatics. 



Typho-Pellagra. — In this disease the dermal signs of pellagra 

 are sufficiently evident to enable its diagnosis to be made, as a rule, 

 without difficulty, while the diagnosis of typhoid fever can be made 

 by the methods already described on pp. 1389-1394. 



Nervous Diseases. — Melancholia, dementia, mania, etc., can 

 only be diagnosed as pellagrous when associated with its skin 

 lesions; but here care must be taken not to mistake the dermal 

 signs of pellagra for chronic eczema, etc.; but this point, having 

 been already discussed above, need not again be argued. 



Prognosis. — ^This would appear to be good in early cases, in mild 

 cases, and even in moderately severe cases, if the patient can be 

 removed from the pellagrous area and placed in good condition of 

 food and hygiene in a non-pellagrous area. 



But predictions as to a cure must be guarded, and it must be 

 remembered that cases have relapsed after two, five, and even 

 fifteen, years' intervals. 



In severe cases the prognosis must be guarded, and the low blood- 

 pressure remembered, as well as the possibility of sudden death 

 from exertion after lying down. 



Cases of typho-pellagra have [a high mortality, and here the 

 prognosis is obviously bad. 



Complication with ankylostomiasis, tuberculosis, etc., also 



