Reference Values for Normal Epidermal Thickness in Koreans: A Histopathologic Investigation

Kim, Jae Hwa; Jung, Kyung Eun; Koo, Dae Won; Lee, Joong Sun

Abstract

BACKGROUND
Epidermal thickness is a useful quantitative histopathological parameter to predict different skin conditions. For accurate diagnosis, the reference values of normal skin histology are essential. Until now, little data regarding epidermal thickness in normal Korean skin have been available.
OBJECTIVE
To investigate the thickness of the epidermis, stratum corneum, and cellular epidermis by skin biopsy and to compare their regional, age, and sex variations in Koreans.
METHODS
A total of 119 normal human skin tissues from 117 subjects were included. Skin specimens were preserved in sections by formalin-paraffin techniques and measured by performing light microscopy and using a calibrated ruler.
RESULTS
The mean thickness of the epidermis was 140.6±32.6 µm (mean±standard deviation). Significant regional variations of epidermal thickness were found (p<0.01): the leg was the region with the thickest epidermis in both males and females (153.3 µm and 183.4 µm, respectively), while the neck was the region with the thinnest epidermis (96.3 µm and 115.4 µm, respectively). However, epidermal thickness did not show any significant difference according to age (p>0.5) or sex (p>0.05, except for the thickness of the stratum corneum of the legs [p=0.007]).
CONCLUSION
Regional variations of epidermal thickness were demonstrated. These variations were mostly independent of age or sex, which conflicts somewhat with previous studies. We present this research as a preliminary study, which may provide reference values for skin histopathology and epidermal thickness in normal Korean skin.