Detection and distribution of endogenous steroids in human stratum corneum

ObjectivesThe objective of the study was to investigate the presence and distribution of endogenous steroids in human stratum corneum (SC) with respect to sex, age, anatomical site, and depth into SC, using a noninvasive sampling technique and a sensitive analytic method for quantitation.Materials and methodsCorneocytes in the SC samples removed by sequential tape stripping from the forearm, forehead, and back sites were processed and analyzed using a validated liquid chromatography–tandem mass spectrometry method for the quantitation of hydrocortisone, cortisone, and testosterone.ResultsIn the 32 volunteers surveyed, testosterone was only detected at the forearm site in a single volunteer. Both hydrocortisone and cortisone were detected in 5–7 individuals out of 16 from both the age 20–35 years and age 50–65 years groups. Maximal amounts of hydrocortisone and cortisone found in SC of forehead, forearm, and back were 0.37 ng/cm2, 0.96 ng/cm2, and 0.49 ng/cm2; and 0.20 ng/cm2, 0.12 ng/cm2, and 0.06 ng/cm2, respectively, and were either higher than or comparable to those reported in human hair in terms of concentration by SC weight. In the population with either hydrocortisone or cortisone detected, no significant differences relating to sex, age groups, and anatomical sites were observed for the amount of hydrocortisone and cortisone in the SC. However, significantly higher amount of cortisone was found in the surface layers of SC than deeper layers in the age 50–65 years group.ConclusionThe results demonstrate that, with the achievable sensitivity of current analytical technology, physiological concentrations of endogenous steroids, such as hydrocortisone and cortisone, can be found in the SC of some individuals.