Surface Skin Temperature in Tests for Irritant Dermatitis

Abstract

Advances in measuring devices have made it feasible to conveniently measure localized changes in skin temperature. A series of experiments were conducted to determine if the addition of surface skin temperature measurements into studies commonly used to screen for skin responses to consumer products would increase the ability to discriminate between similar, mild products. Three testing protocols were evaluated: the modified arm patch with 24-h occlusive exposure for 4 consecutive applications, the behind the knee (BTK) with 6-h occlusive exposures with pressure for 5 consecutive days, and the bikini area shaving study with assessments after manual shaving by women with self-reported irritation after using a manual razor. In the modified arm patch studies, the positive irritant control (0.1 % sodium lauryl sulfate) produced mean erythematous scores that were higher (p < 0.05) than reactions produced by the negative irritant control (0.9 % saline), or the mild products. The skin surface temperatures were not significantly different in any arm patch study. In the BTK the two mild products produced significantly different levels of erythema at both the afternoon scoring (30–60 min after sample removal) and the morning scoring (after approximately 18 h of recovery). Skin surface temperatures differed only at the morning scoring. In the bikini area shaving study, mean erythema after 48 h was lower (p < 0.05) than after 5 min or 24 h on the left side only, indicating some degree of handedness. Skin surface temperature was significantly higher prior to the shaving exercise than at any of the subsequent scoring time points. Results indicate that the addition of measurements of skin surface temperature using DermaTemp® to standard exposure protocols used to evaluate potential skin responses to consumer products would not increase the ability to discriminate between products.