Figure l pphenylamine diamine hair dye dermatitis

SKIN REACTIONS TO COSMETIC PREPARATIONS their hair at the temples, the only common factor being the use of a detergent shampoo. Some time after shampooing, the hair can suffer abnormal moisture-loss probably because the shampoo has removed hygroscopic nitrogenous material. It has also been shown that detergents can aid the penetration of various chemical agents. Kligmann has claimed that human sebum has no function except as a protective to the hair whereas a fatty- coated hair floats on water, a defatted one will sink. The harmful effect that may result from excessive detergency may also be due to denaturation of keratin, for it has been shown that an increase in the number of sulphydryl groups is demonstrable. •IR. A. W. POND: I should like your comments on the possible relationship between degreasing by shampoos and increased skin-shedding from the scalp, which may be regarded as dandruff although not micro- biological in origin. T•E LECTURER: Detergents do seem to increase the scaling process. Dandruff often appears as a mixture of sebum and scale packed together. The right way of coping with the hair is to brush it frequently with a soft bristle brush so as to distribute the sebum down the hair and keep it pliable, rather than washing it too often. MR. N.J. VAN ABBE: In my laboratory, we have tried to find the reasons for embrittlement of the hair, but have been unable to show any connection with shampooing under reasonable conditions. Hair damage could only be demonstrated with vigorous mechanical treatment, such as many women do, in fact, employ. My question relates to your views on the relative importance of the incidence of reactions to cosmetics, and the severity of the responses en- countered how should one decide whether it is justifiable to use a particular ingredient ? T•E LECTURER: This is a calculated risk though we may see one or two cases of sensitivity, we generally have no idea of the number of people exposed to the risk, especially as formulae are seldom published. If it is a question of causing a little mild dermatitis, one need not worry too much. If the result is more serious, such as causing nephritis or even death, then the problem demands more attention. Usually, however, there is no such danger and a calculated risk is permissible. DR. H. W. HIBBOTT: IS there any evidence that cosmetics can block the pilosebaceous orifices, despite the positive pressure tending to exude aqueous and oily secretions. Are such effects, if any, mechanical, physical or chemical ? TeE LECTURER: On the skin, the hair follicles bear small hairs but