B VITAMIN DEFICIENCY STATES 409 



lagra. Sunlight in some manner and to an unknown extent plays an 

 important role in the disease. 85 With the exception of the characteristic 

 vaginal and scrotal lesions, the early skin lesions generally follow exposed 

 parts of the body, and it has been suggested that some photodynamic 

 action at the site of the chromatophores may promote this pathological 

 characteristic. Strong sunlight is also known to cause relapse in patients 

 in remission. It has further been suggested that the characteristic out- 

 break of the disease in the spring may involve sunlight, although it seems 

 more likely that this is due to the accumulated effects of the nutritional 

 deficiency acquired during the winter months. 



A number of factors combine to make pellagra particularly perni- 

 cious. Pellagragenic diets are generally deficient in thiamine, riboflavin, 

 and pantothenic acid, and perhaps still other factors, and the mul- 

 tiple nature of the avitaminosis has a weakening effect on the body 

 which leaves it poorly able to withstand the most pronounced deficiency 

 of niacin. Disturbed gastrointestinal function also plays a major role in 

 the etiology of niacin deficiency. Dysentery, colitis, intestinal parasitism, 

 and surgery are all known to be strong predisposing factors toward 

 pellagra, as they are toward beriberi. It would seem that in these 

 deficiencies there is a strong probability of the creation of a vicious cycle, 

 the deficiency leading to further gastrointestinal disturbances which in 

 turn encourage the avitaminosis. The exact manner in which such organic 

 afflictions promote deficiency is unknown, although faulty digestion and 

 absorption seem likely. It is of considerable interest that gastric prepara- 

 tions have been successfully used for many years in the treatment of 

 pellagra, and there is at least some evidence to indicate that their efficacy 

 may not be due to the niacin content. 86 (Certain liver fractions which 

 have a low niacin content are similarly quite active) . 



In its essence, as Goldberger pointed out, the major causes of pellagra 

 seem to involve first dietary factors, and secondly factors that prevent 

 the normal utilization of the diet by the individual. 87 The disease is com- 

 mon in children and persons of all ages and racial stocks, being most 

 pronounced in adult married women. Finally, when all the known etio- 

 logical factors are taken into consideration, it is still difficult to explain 

 the fact that in both man and experimental animals and without any 

 dietary change, there is a frequent spontaneous remission of niacin 

 deficiency which, however, is seldom long-lasting. 



As previously stated, pellagra characteristically develops in the early 

 months of the year. In some acute cases the symptoms become progres- 

 sively worse and death ensues. In the majority, however, the symptoms 

 develop for only a few months and then disappear for the most part and 

 in some cases never return. Generally there is an annual recurrence 



