136 CAROTIXOIDS AND RELATED PIGMENTS 



due to a carrot diet. Carotin was inferred, not demonstrated, in these 

 cases, although Salomon measured the extent of the "xanthemia" in 

 certain individuals by determining the extinction coefficient of the 

 absorption bands of the ether extract of the blood. 



Von Noorden (1904) first called attention to a frequent yellow skin 

 coloration in diabetics, which was not due to jaundice. He proposed 

 for it the name Xanthosis Diabetica. Van den Bergh and Snapper 

 (1913) also called attention to the phenomenon and showed in addition 

 that it was accompanied by an increased lipochrome content of the 

 blood serum, which they regarded as the cause. Umber (1916) noticed 

 the same correlation in cases of Xanthosis Diabetica. Burger and 

 Reinhart (1918) first suggested an exogenous origin of the pathological 

 phenomenon, for which they later (1910), as well as Salomon (1919), 

 offered proof. Hess and Myers (1919) saw the correlation between 

 the pathological and normal skin colorations on carotinoid rich diets, 

 and van den Bergh and Muller (1920) and van den Bergh, Muller and 

 Broekmeyer (1920) have presented such extensive data on the pres- 

 ence of carotinoids in the human organism that their conclusion seems 

 entirely justified that the skin colorations of diabetics is due pri- 

 marily to the vegetarian character of the diet of persons afflicted with 

 this disease. It is not to be inferred, however, that carotin is always 

 the cause of the skin coloration. Head and Johnson (1921) with the 

 assistance of the writer have demonstrated carotin as the sole cause 

 of one case where the diet of the diabetic was rich in carotin (the 

 patient ate heavily of -carrots), the skin clearing up when the source 

 was removed. On the other hand another case of skin coloration of 

 a diabetic has come under the observation of the writer which was 

 evidently due largely, is not entirely, to xanthophylls. The diet was 

 rich in xanthophylls (eggs and green beans), and the blood serum 

 showed much xanthophyll with little carotin. The skin in this case 

 was also cleared up by removing the source of the pigment. 



In view of the fact that carotinoids have been found in the skin of 

 both normal and diseased persons, it seems doubtful whether any 

 pathological significance can be attached to its appearance in the skin. 

 Van den Bergh, Muller and Broekmeyer (1920), who have studied 

 this question extensively, were unable to note any correlations between 

 the pigmentation of various tissues and tfye character of the disease. 

 The difficulty, of course, is that the pigments must be of dietary origin. 

 Even a diabetic could not show a xanthosis unless his diet contained 

 carotinoids. On the other hand the more frequent observation of an 



