THE DERMATOLOGIST LOOKS AT THE HAIR PROBLEM 133 hilarators, hair restorers, and hair dressings on the market, it is start- ling that we have absolutely no definite proof as to whether any external application made to the skin or hair, has any effect on hair growth. In fact, the most careful experiments that have been done to date, and there are not many recent ones, indicate that nothing that we apply to the skin or hair appears to have any appreciable effect on the rate of hair growth and that any of the apparently bene- ficial effects noted, may be due to the massage, hyperemia, or in- creased vascularity brought about in their application. But even the question of whether beneficial effect ensues from massage in humans has not been proved. Animal ex- periments indicate that it is the massage and not the local applica- tions that are beneficial in increas- ing rate of hair regrowth. In this field alone, it would seem to me that research should be undertaken to establish once and for all, the role of local application and massage. Furthermore, studies shoald be done to determine which vehicles are best suited, physiologically and chemi- cally, and what 'types of stimulants or irritants could best be added to them to benefit the vascularity of the papilla, follicle, and hair in its life cycle. The exact shape of the hair in different races and individuals is also not entirely settled. In some races, the hairs are oval or ribbon shaped, while in others there is a tendency for the hair to approach a rectangular form, smooth ellipse, circular form, etc. It is difficult to discover this without having the hairs arranged for examination so they can be rotated under the microscope. Also just what causes naturally curly or wavy hair is not known. 'Fritsch (5) says that while curly hair behaves in general as a dominent trait, there is no definite sign of Mendelian segregation in future generations. It is possible that the characteristic bend of the follicle immediately above the ß papilla is the point where the tend- ency to curl is really imparted. Supposition but not facts! Even the pigmentation of the hair is not too well understood. Rothman and Flesch (6) reported on the isolation of a red iron pigment from human red hair. The pre- sented data indicated that it may be a complex phenolic iron compound in which the phenolic OH group is attached to a heterocyclic ring con- taining nitrogen. This pigment was not obtainable from red hair of ani- mals or from any human hair ex- cept bright red. The literature on the darkening of hair with age is meager, general, and as far as known to Steggerda (7) never quantita- tive. Two hundred and twenty males and one hundred and ninety- four females ranging in age from 6 to 18 were measured annually for 10 years in Holland, Michigan. The study showed that the head hair becomes darker by almost one unit on the Fischer-Saller hair scale with each year of age for the ages 6 to 18. No significant sex differ-

134 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS ences were to be noted. Changes of color are brought about by many factors and the natural and sudden graying of 'the hair are explained by many theories that have not been at all proved. Probably the greatest amount of recently recorded work done on any phase of the hair prob- lem has been done on the effect of vitamins, etc., on the graying of the hair. In a recent summary in the Nutritional Review (8), it was noted that the causes of achromo- trichia are not well understood. Both dietary deficiencies and hor- monal disturbances have been im- plicated. A deficiency of panto- thenic acid is known to result in graying of the hair in rats and other experimental animals and there is evidence that additional factors in- cluding para-aminobenzoic acid may at times be involved. On the other hand, the many studies that have been made, give us little reason to believe that human achromotrichia is caused by a dietary deficiency. In man, the process of graying and of aging are frequently associated and there is a popular belief that graying may b• accelerated by emotional stress. It is not sur- prising therefore, that hormonal control of the graying process should have been suspected even though direct experimental evidence has in a large measure been lacking. This confused picture has been somewhat clarified by Ralli, et al., who have shown that even in experimental animals rendered gray by a defi- ciency in pantothenic acid, adrenal- ectomy will bring about the restora- tion of the original color of the hair. It appears that hormone balance, dietary deficiency, and possibly mineral and water balances may in- fluence the production of melanin or its deposition in the l•air and skin. The hormonal control must be particularly strong since =drenal- ectomy overcomes the effect of a pantothenic acid deficient diet. It is not yet clear, however, whether the various factors operate through single or separate mechanisms and the nature of these processes is not well defined. The tendency to production of hairs of a finer, more silky character in advanced life, is caused by sebor- rhea according to Sabouraud (Sa) and is not a natural phenomenon of normal hair growth as was once supposed. This is explained as being due to a mechanical plugging of the follicles. The matter of pre- mature alopecia, therefore is a very complicated one in which probably many factors come in to plash. Studying the fundamentals and going back to the mechanism of the replacement of the hairs which are constantly being shed, therefore, would seem to be the logical ap- proach to the solution of this prob- lem. The question whether the vascular supply controls this me- chanism and the factors that might influence or control the vascular supply is therefore of the utmost interest and importance. Wright, et al. (Sb) studied seborrheic der- matiris and found the administra- tion of vitamin B0 (pyridoxine) re- suited in definite impro.vement and