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Predicting of
Skin Sensitivity Using Skin Types and Colorimetry
Cestari, Tania1,
Albaneze, Ricardo1, Cursio, Beatriz1,
Rehn, Mariane1, Di Domenico, Emileine1
and Dornelles, Sergio1
School of Medicine, University of Rio Grande do Sul, Brazil1
Abstract-
There is a strong relation between chronic sun exposure and the development
of skin cancer. This study aimed to obtain a more reproducible method
to detect individuals with apparently similar skin types but different
sun sensibility. METHODS: Healthy volunteers, older than 18 years were
evaluated according to Fitzpatrick's criteria and had their skin
examined. The minimal erythema dose (MED) was determined in 2 non sun-exposed
areas (lower back and lateral trunk), using a UVB source (0.5mW/cm2
), in crescent doses. Colorimetric assessment was performed with a Minolta
CR 300 Chromameter (L*a*b* system) in both areas. RESULTS: 194 individuals,
68% female, mean age of 38 years, regularly distributed by skin type.
The values of MED ranged from 13 - 156mJ/cm2 and the Spearman's
coefficient was positive between MED and phototype (
= + 0,95, p
0,05). The values of coordinate L* (brightness) ranged from 75.96 -
30.15 with a negative Spearman's coefficient between brightness
and phototype (
=  0,93,
p 0,05 in
the trunk, and
= 0,92
p 0,05 in
the buttock). The correlation between MED and brightness was strongly
negative in both areas (Pearson's correlation
= 0,91,
p0,05).
CONCLUSION: MED is a more precise method to predict sunburn risk; however,
color measurements, especially brightness, can reliably be used to quickly
assess skin sensitivity since both variables present a regular distribution,
with correlate values according to skin type. It is important to evaluate
areas with minimal external influence such as hair, veins and scars,
to obtain comparable results. There is an overlap among the groups probably
explained by racial and ancestry factors but also a clear separation
between more sensible individuals (type I, II and III) and less sensible
ones, comprising 2 individual groups with different sun exposure response.
Skin color determination can be a useful tool for the institution of
educational and preventive actions.
Keywords: UVB
sensitivity , minimal erythema dosis, skin typing, skin colorimetry
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