Moisturizers prevent irritant dermatitis.

The purpose of this study was to investigate the ability of eight different moisturizers to prevent irritant dermatitis. Twelve healthy female students washed the outer aspect of their upper arms with a liquid detergent for one minute twice a day for one week. Seven skin creams and one skin oil were applied to 3 x 7 cm areas of the left upper arm just after each washing, while the right upper arm was left untreated. Transepidermal water loss (TEWL) (mean) increased from 7.1 to 9.3 g/m2/h (p less than 0.001) and laser-Doppler flowmetry (LDF) value (mean) decreased from 11.8 to 10.8 arbitrary units (N.S.) in the left upper arm, but there was no statistical difference between the eight moisturizers. During the second week of the study, the test subjects did not continue washing their arms. Eight areas (3 x 7 cm) of the right upper arm were treated with the moisturizers twice a day. The mean TEWL value decreased from 20.3 to 8.6 (p less than 0.0011) over 7 days, but there were no significant differences between the individual moisturizers. The laser-Doppler values showed the same trend as the TEWL values. In conclusion, regular use of emollients prevented irritant dermatitis from a detergent.