Photoaging of the chest analyzed by capacitance imaging.
OBJECTIVE
Capacitance imaging is a new technique using sensors based on silicon technology developed to record fingerprints for security reasons. Applying such a sensor onto the skin surface gives the capacitance (hydration) map of the skin surface with a two-dimensional resolution of 50 microm. This method was used to characterize skin of the chests of 64 women with various grades of skin photoaging.


METHODS
The severity of photoaging of the chest skin of 64 women was clinically assessed according to a six-grade scale. Capacitance images of the skin were recorded and analyzed in terms of mean capacitance, homogeneity of gray levels and density of microrelief lines. Capacitance images of the adjacent unexposed area (upper part of the breast) were also recorded and analyzed for comparison. Pictures of the different areas were recorded.


RESULTS
Microrelief line density decreases with the age of the volunteers but is independent of the severity of photoaging. Mean hydration of the skin surface is found to be independent of both photoaging severity and age. Evenness of hydration is a parameter markedly linked to the severity of photoaging independent of age. Uneven hydration is related to the juxtaposition of both hydrated and dry areas corresponding to some hyperpigmented and hyperkeratosic areas. Moreover, capacitance images reveal that some of the hyperpigmented areas may exhibit under- or over-hydrated conditions depending on the nature of the lesion.


CONCLUSIONS
Irregular skin surface hydration is an important characteristic of skin photoaging. It is related to skin pigmentation but does not parallel its unevenness of pigmentation.
Bazin
Roland
R
L'Oréal Recherche, Chevilly Larue, France. rbazin@rd.loreal.com
Laquièze
Sabine
S
Rosillo
Aline
A
Lévêque
Jean Luc
JL
D000328:Adult; D000367:Age Factors; D000368:Aged; D001940:Breast; D025802:Electric Capacitance; D005260:Female; D006801:Humans; D008875:Middle Aged; D012869:Skin Absorption / Q000502:physiology; D015595:Skin Aging / Q000502:physiology*; D012871:Skin Diseases / Q000175:diagnosis* / Q000378:metabolism; D012880:Skin Pigmentation / Q000502:physiology; D013909:Thorax; D014867:Water / Q000378:metabolism*; D055815:Young Adult
D014867:Water