Introduction: Knowledge of basic elements gives a clear vision of the structure of any organ. Skin is continuously being exposed to various external environmental factors, one of them is sun induced UV radiation, major environmental factor that affects the structure and function of human skin. On excessive exposure, UV radiation can cause premature aging and even skin cancer. Histological analysis of the variations among sun exposed and non-sun exposed human skin is of relevance in dermatologic research and dermatopharmacokinetics.

Materials and Methods: This study was conducted on 10 male and 10 female human cadavers. The rectangle shaped skin specimen (1 cm × 1 cm) was taken from two sites sun exposed (forehead) and non sun exposed (lower abdomen) and stained with hematoxylin and eosin stain. A total of 40 slides were prepared. Readings were obtained with the help of cellSens/OLYMPUS Stream software, using UIS2 (Universal Infinity System) optical design camera fitted in the light microscope.

Results: There were statistically significant differences among sun exposed and non-sun exposed area was found in epidermis (p=0.008 & r=0.754), no. of rete pegs (p=0.05 & r=0.573), no. of hair follicles (p=0.04 & r=0.565) and depth of rete pegs (p=0.03 & r=0.102).

Conclusions: The mean value of epithelium of sun exposed site is marginally thicker than non-sun exposed sites. The number of rete pegs per field was higher in exposed site as compared to non-sun exposed site.

Keywords: Dermatopharmacokinetics, Skin, Histomorphometry