BACTERIOSTATIC SOAP 165 rash. In the cases of the five categories, the numerical coding (0-7) was used as the dependent variable. In such an analysis the "level of significance" is an indicator of the likelihood that there is a difference among the categories within each factor. The higher the level of significance the more likely a difference exists among the categories. For values less than 90 it is customary to consider the results not significant (N.S.). Values greater than 99 are considered highly significant. Table II lists the analysis of variance of incidence and severity of erythema. Table II Analysis of Variance of Incidence and Severity of Erythema Degrees of Level of Source of Variation Freedom Square Value Significance Change with Soap A vs. change with Soap B 1 Soap 1 Time 4 Sex 1 Age 1 Soap X time 4 Soap X sex 1 Soap X age 1 Time X age 4 Time X sex 4 Sex X age 1 Soap X time X sex 4 Soap X time X age 4 Soap X sex X age 1 Time X sex X age 4 Soap X time X sex X age 4 Error 460 17.113 26. 450 90. 254 19 602 0 162 5 386 1 682 5 618 1 308 0. 378 3. 042 1. 386 1.212 4. 802 0. 496 1. 788 1. 339 12. 19. 67. 14. O. 4. 1 4 0 0 2 1 0 3 0 1 78 99.9 75 99.9 40 99.9 64 99.9 12 N.$. 02 99.5 26 N.S. 20 95 0 98 N.S. 28 N.S. 27 N.S. O4 N.S. 91 N.S. 59 90.0 37 N.S. 34 N.S. ß . . Table III Significance Level of Change in Symptoms, Soap A w. Soap B Symptom Level of Significance Erythema 99.9 Scaly dermatitis 99.0 Eczematold derlnatitis N.S. Ulcerative dermatitis N.S. Vesicular dermatitis N.S. Total diameter of rash 99.5 The other symptoms were subjected to a similar analysis, The level of significance for the change with Soap A vs. change with Soap B for the various types of dermatitis is summarized in Table III.

166 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS •)ISCUSSION AND CONCLUSIONS The nature of the experimental setup (the examination of the inci- dence and severity of diaper rash during a four week period immediately following a time when all symptoms were absent and its comparison with a previous score reflecting the most severe episode in the past) accounts for the improvement noted with "time" and "soap" (both kinds) and their highly statistical significance. Of practical and paramount impor- tance in the present study is the high statistical significance of the "change with Soap A vs. change with Soap B" for the categories: Erythema, scaly dermatitis, and diameter of the rash. The lower occurrence of statistically significant results for the more serious categories (and, in particular, the absence of a significant differ- ence between the two soaps) reflects the paucity of data in these cate- gories due to the very low incidence of these symptoms. The finding in this study of a highly significant age and sex depend- ence of incidence and severity of diaper dermatitis corroborates pre- viously reported results. SummARY The severity and incidence of diaper dermatitis during the use of germicidal commercial soap (A) was investigated over a period of 28 days and compared with those during the use of a nonmedicated soap. For the relatively common varieties of diaper dermatitis symptoms (erythema and scaly dermatitis) and the over-all diameter of the rash there was a significant reduction in the average severity and incidence when Soap A was used. For the less common and more serious varieties of symptoms (eczema- toid dermatitis, ulcerative dermatitis, and vesicular dermatitis) the reduction in average severity and incidence by the medicated soap was not significantly different from the comparable reduction with ordinary soap. The average severity and incidence of all varieties of diaper derma- titis is significantly higher in males than in females and, among both males and females, among the older (9 months and over) infants. (Received September 20, 1966) BIBLIOGRAPHY (1) Dubow, E., Ammoniacal dermatitis in infants, Arch. Pediat., 71,323-20 (1054). (2) Fijan, K. J., Jolliff, C. R., and Engelhard, W. E., Treatment of diaper rash with an aerosol product, Clin. Med., 71, 1335-42 (1004).