Skin surface topography grading is a valid measure of skin photoaging

Abstract

Background: The technique of grading the surface topography of sun-exposed skin using silicone impressions of the skin surface is a simple, non-invasive method for measuring skin damage because of sun exposure, but it has never been validated in a community setting.

Objective: To investigate the repeatability and validity of using standardly-graded skin impressions as a means of assessing skin photoaging.

Patients/methods: A random sample of 195 adults aged 18-79 years and living in Nambour, Australia (latitude, 26 degrees South) had a silicone impression taken of the back of the left hand and a 2 mm punch biopsy of the skin at the same site. Silicone impressions were graded twice independently and histological photoaging was determined by two pathologists.

Results: Grading of silicone impressions of skin surface topography was highly repeatable (weighted kappa > 0.8). Compared with those with low skin impression grades (least degeneration), people with high grades were three times more likely to show a high degree of dermal elastosis on skin histology (odds ratio 3.1, 95% confidence interval 1.6, 5.7) after adjusting for age, sex, skin colour, tanning ability, occupational exposure, smoking and height-adjusted weight. Other photoaging changes in the stratum corneum and dermis were also strongly correlated with high grades of damage on skin impressions.

Conclusion: Grading silicone impressions of skin surface topography is a highly reliable and a valid measure of photoaging and enables prediction of dermal elastosis in a population setting.