Cleansing trends promise freshness, sensory and health benefits but may also be accompanied by an increase in
soap-induced skin irritation. The aim of this study was to evaluate the
irritant effect of 31 cleansers (28 bar
soaps and 3 liquid cleansers) available in the Indian market. Eight percent w/v solutions of the
soaps/cleansers were made and 30 microL of each of the solutions were applied to Finn chambers and occluded for 24 h along with distilled water (negative control) and 20%
sodium dodecyl sulphate (SDS) as positive control. The sites were graded for
erythema and scaling 30 min after removing the patches. The pH of each of the
soap solutions was determined. Mean with SD and ANOVA (F-value) was computed separately for each
soap/cleanser with respect to the two parameters,
erythema and scaling. The total of the means for both the parameters,
erythema and scaling was also computed. The cleansers were listed based on this total from the least
irritant to the most
irritant. The differences between
soaps (F-value) was significant for
erythema and scaling [
erythema = 4.106 (P = 0.000); scaling = 6.006 (P = 0.000)].
Cetaphil cleansing lotion had the lowest
erythema score of 0.25. Lowest scaling score of zero was recorded for
Cetaphil cleansing lotion and Elovera moisturizing body wash. Aquasoft and Lifebuoy
soaps had the highest
erythema score of 2.13. Acnex had the highest scaling score of 1.75; Aquasoft, Hamam scrub bath
soap and Naturepower sandal
soaps were the next with a scaling score of 1.63.
Cetaphil cleansing lotion, Aquaderm liquid
soap, Dove bar
soap and Elovera moisturizing body wash proved to be the least
irritant cleansers with a total score of less than 1. The four most
irritant soaps/cleansers had an average score of 3.65. The
irritant potential of the majority of the cleansers fell between these extremes. The pH of all the
soap/cleanser solutions was neutral to alkaline (pH 7-9) except that of Dove bar,
Cetaphil cleansing lotion, Aquaderm liquid
soap and Elovera moisturizing body wash which tested acidic (pH 5-6). The pH of the positive control--20% SDS, was acidic (pH 6). The difference in the irritancy potential between
soaps/cleansers as determined by the 24-h patch test was significant. There were individual variations in the
irritant potential of the
soaps/cleansers in the volunteers, thus when the patient queries on what
soap to use, it may be advisable to test each patient separately and educate him/her regarding the
soaps/cleansers less likely to cause irritation. The limitations of the study was that it was single blind and non-randomized as all the 14
soap solutions were applied on 15 volunteers in the first panel and subsequently all the 17
soap solutions were applied on eight volunteers in the second panel. However, we could compare the
irritant potential of 31 cleansers. The results of 24-h patch testing of 31
soaps/cleansers in the Indian market in two panels of 14 and 17
soaps/cleansers on 15 and eight volunteers, respectively, are presented.