The skin surface characterization has a great importance for dermatologists as well as for cosmetic scientists in order to evaluate the effectiveness of medical or cosmetic treatments. Skin topography characterization has been faced by using profilometers and skin replicas to achieve some measurements related to either skin 3D profile or wrinkles. So far, no in vivo measurements regarding skin topography changes have been achieved to evaluate skin ageing. This work describes how a portable capacitive device, normally used for fingerprint acquisition, can be utilized to achieve measures of skin ageing routinely. The capacitive images give a high resolution representation of skin topography, in terms of wrinkles and cells. In this work we have addressed the latter: cells have been segmented using the watershed approach and a feature related to their area distribution has been generated. Accurate experiments accomplished in vivo show how the feature we conceived is linearly related to skin ageing.