232 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS evaluating the sensitizing effects of materials by relying on the reac- tions of two hundred subjects to patch tests dictates caution in formulating conclusions based upon such a number of patch tests alone. More recent methods, some of which have been adopted in this study, yield results affording greater precision in their interpretation. For example, (1) the routine use of adequate numbers of paired patch tests (equivalents to four or the usual single patch tests) (2) the retesting within two to four weeks of each individual in order to deter- mine any development of sensitiza- tion and (3) most important of all, an adequate experience over a prolonged period of time under conditions of actual use, are the innovations which have been adopted. These have strengthened the validity of conclusions based upon the relation between actual us- age and the incidence of positive skin patch tests, on the one hand, and the occurrence of dermatitis from contact with cold wave lotions, on the other. Whereas the adequacy of patch testing when used alone as a measure of irritancy and al- lergenicity may be reasonably open to question, the authors believe that the experimental procedure in each case must be subjected to in- dividual considerations. In this connection, a recent publication (6) from our service at Bellevue Hos- pital may be cited. Patch test reactions to a mild fungicide were compared with the incidence of reactions occurring under actual usage conditions. It was found that patch tests gave reactions which were much more frequent and severe than the incidence of dermatitis when the material was in actual use. A number of subjects who were tested by standard patch test meth- ods responded to the chemical with moderate to severe reactions. These same subjects were subsequently subjected to the daily therapeutic use of the identical chemicals with- out eliciting any cutaneous reac- tions, even after prolonged use. A possible interpretation for these findings is that in actual use the composition of the reactive chemi- cals may have been altered by such factors as volatility, 5nstability and reactivity with the air, the skin and with any other materials. A substance should be rejected as an irritant or accepted as inert only when the results of patch tests are confirmed by actual use. In this investigation of cold hair waving lotions, over 1200 persons in varying degree of contact with such preparations were used as sub- jects. The first phase of these studies dealt with the primary irritancy of ammonium thioglycol- ate. It was shown to be of a low order, even when the concentration was triple that of the solution in common use. Paired patch tests using the solutions employed in the cold wave process were performed on several hundred subjects with various skin diseases. These tests showed that the cutaneous reac- tions from contact with or exposure to. these materials were of a neg-

COLD WAVE LOTIONS CUTANEOUS AND SYSTEMIC EFFECTS 233 ligible incidence and sensitizing po- tential. In addition to the lotion, a lock of the subject's hair was in- cluded under the patch, in testing some of the subjects. This was done in order to determine the re- activity of any chemical product which may have been formed by the action of the waving lotion upon the hair. No skin reactions oc- curred. Neither the size nor the de- gree of saturation of the patch in- duced any reactions, when tests were performed with a wide varia- tion in these factors. Patch tests and physical examinations were also performed on 931 individuals, many of whom were factory employees engaged in the manufacture of, and in constant or frequent contact with, cold wave preparations. Not one of these individuals gave evi- dence of any skin condition or of systemic disease in any way refer-. able to intimate contact with the lotions. A preliminary study of employment statistics had shown this group to be a representative cross section of the population and not a selected, immune or "hard- ened" group. When 863 individuals of the group were patch tested, 16 showed weakly positive reactions. Upon retesting 15 of them, only two were again positive. One of the latter had been intimately and frequently exposed to the cold wave !otio_n_s for over two years without any evidence of adverse effects. The other individual had five cold permanent waves without any cu- taneous reactions. Examinations made of the scalps of 174 women undergoing actual waves with the waving materials showed no ad- verse effects. Each of these women previously had from one to twenty cold waves. These subjects were patch tested immediately before the administration of a cold wave and read 24 and 48 hours thereafter. A weakly positive reaction occurred in but one individual. It is of interest that this individual was then undergoing her fourth cold permanent wave. No untoward ef- fects resulted from either the present applications or from her three pre- ceding cold waves. The beauty parlor operator had been instructed to bathe the scalp with the lotion, in order to obviate the criticism that unusual care had been employed in giving the permanent wave. The data obtained from this study em- phasizes anew the precept that 'skin reactivity to patch testing should be evaluated only in con- junction with actual usage experi- ence. Thorough physical and laboratory examinations of 226 individuals ex- posed in varying degrees to cold wave lotions failed to disclose evi- dence of any acute or chronic condi- tion which might indicate the pres- ence of disease of the liver, the kidneys, or the hematopoietic sys- tem. The results of complete blood studies followed a standard distribution curve similar to that seen in general clinical practice. Urinalyses were considered to be within a normal range. In view of previous reports of liver damage due to contact with cold wave lotions,