130 INANITION AND MALNUTRITION 



added to the diet and the color soon disappeared, on account of the resumption 

 of growth in the hairs as in other parts of the body. Drummond ('16), however, 

 noted continued growth in beak and feathers of chickens held at constant body 

 weight (100-150 g.) by rice diet (mixed deficiency) for periods of 20 — 80 days. 

 Zuntz ('20) concluded that the growth of the epidermal structures (including 

 hair and nails) may be restricted by lack of cystin, and he obtained increased 

 growth of hair in sheep and man by addition of hydrolized horn to the diet. 

 The literature on alopecia in animals on various artificial diets is reviewed by 

 Bruning ('14a). 



Malnutritional Edema. — As already mentioned, cutaneous edema (with or 

 without general anasarca and ascites) may be produced experimentally in rats 

 by diets deficient in protein or fats, and similar deficiencies may be responsible 

 for the edemic cachexia found in domestic animals and in conditions of human 

 famine. Many authors, however, consider that "famine edema" and allied 

 conditions are due to general inanition rather than to any specific deficiency. 

 Cutaneous edema is usually associated with atrophy of the adipose tissue. 

 Cramer ('23) found that in young rats on a diet deficient in tryptophan: " The 

 hair falls out in patches after 6 or 7 weeks of this diet, and after another 8 or 10 

 days there is an extensive oedematous condition extending over parts of the 

 trunk and stretching the skin." This cutaneous myxedema was ascribed to 

 hypothyroidism, due to extensive lesions in the thyroid gland. 



Cutaneous Lesions in Pellagra. — As previously mentioned, the exact etiology 

 of pellagra is yet somewhat uncertain, although it seems probable that protein 

 deficiency in the diet is at least an important factor. The cutaneous lesions are 

 variable according to the stage and severity of the disease, and are sometimes 

 absent ("pellagra sine pellagra"). While space does not permit the review in 

 detail of numerous observations on the cutaneous pathology in pellagra, the 

 more recent papers by Griffini ('70), Raymond ('89), Babes and Sion ('01), 

 v. Veress ('06), Gurd ('n), Roberts ('12), Fiocco ('12), Raubitschek ('15) and 

 MacNeal ('21) may be cited. It is of interest to note that in some preliminary 

 therapeutic trials by Goldberger and Tanner ('22), the dermal lesions in 2 cases 

 reacted favorably to cystin, and in a third case to cystin and tryptophan. 



In general, the human skin in pellagra shows an acute stage of erythema 

 (similar to that in sunburn), followed by a chronic stage of atrophy and pig- 

 mentation. The pigmentation usually affects the areas exposed to the sun, and 

 appears in patches symmetrically disposed on both sides of the body. 



The histological changes in the acute (erythematous) stage usually involve 

 inflammatory phenomena, with more or less edema in both epidermis and dermis. 

 The epidermis undergoes proliferation and desquamation, with degeneration 

 changes frequently forming blebs in the stratum germinativum (Malpighian 

 layer). The dermis shows congestion, with marked fibrosis and pigmen- 

 tation. Later the acute symptoms subside and a chronic condition of general 

 atrophy in all layers of the skin gradually supervenes. This atrophy resembles 

 that characteristic of old age, with hyalin degeneration and sclerosis in the 

 blood vessels. Marked cutaneous edema may be present, but this "wet form" 

 appears less frequently. 



