B VITAMIN DEFICIENCY STATES 407 



cent of the cases are under two years of age is known as Kwashiorkor, 

 or "infantile pellagra," and is thought to be a compound deficiency in 

 which ariboflavinosis is predominant. 07 - 68 A recent case of ariboflavinosis 

 in India was characterized by vulval pathology, a symptom not generally 

 seen in cases reported from other areas, 09 and still other atypical forms 

 may arise among different population groups. 



Riboflavin deficiency was first studied in the rat (in 1926) and termed 

 "rat pellagra," and the curative agent was termed the "pellagra-preven- 

 tive factor," although it is now known that the symptoms studied were 

 those of ariboflavinosis, and that the factor involved was riboflavin and 

 not the main curative agent for human pellagra. The first symptoms in 

 the rat are a cessation of growth, and this fact has long been used as the 

 basis for a riboflavin assay technique. Shortly thereafter there is a general 

 loss of fur and a characteristic symmetrical dermatitis of the ears, upper 

 chest, and extremities. The tail becomes dry and scabby, the eyeballs 

 sunken and lids swollen; corneal vascularization occurs as in man, and 

 is among the most striking characteristics. Cataract has been reported by 

 some workers, but there is much disagreement as to its general occur- 

 rence. 70 Granulocytopenia and anemia also occur in severe cases 71 of 

 ariboflavinosis in rats, dogs, swine, and monkeys, although in some cases 

 folic acid deficiency seems to be involved in an unclear manner with this 

 symptom. Swine are said to develop cataracts when suffering from aribo- 

 flavinosis, but there is apparently no corneal vascularization. 



In young chicks on a prolonged mild deficiency there is a highly 

 characteristic "curled toe paralysis." On a completely deficient diet chicks 

 exhibit an acute paralysis and dystonia, rapidly followed by death. 

 Dermatitis is rare but does occur in turkeys. Eggs from hens on a low 

 riboflavin diet fail to hatch, although injection of riboflavin into the egg 

 on the first day of incubation remedies this defect. 72 



Riboflavin deficiency has been extensively studied in dogs. These 

 animals rapidly become weak, reluctant to walk, and exhibit an ataxia. 

 Vomiting and occasional convulsion also occur. After some time in this 

 unhealthy stage the animals develop a diarrhea, followed suddenly by 

 collapse, coma, and death within a few hours. This rather dramatic rapid 

 terminal stage is not seen in rats, and only in chicks on a completely 

 deficient diet. 73 



The biochemical changes occurring in ariboflavinosis have not been 

 well studied, although a number of pertinent observations have been 

 made. There is of course a diminished level of riboflavin and its adenine 

 dinucleotide in the body and urine under deficiency conditions. The 

 xanthine ovidase (p. 148) activity of deficient rat liver, as measured by 

 oxygen consumption rates, is very low. 74 Liver slices from deficient rats 



