The SCINEXA: a novel, validated score to simultaneously assess and differentiate between intrinsic and extrinsic skin...

Studies on the pathogenesis of skin ageing as well as efficacy testing of cosmetic and aesthetic measures to prevent or reverse skin ageing require - as an easy to use method - a validated non-invasive clinical score, which allows to simultaneously assess and differentiate between intrinsic (=chronological) and extrinsic (=photo-) skin ageing. Such an ideal score, however, does currently not exist.

We developed a novel skin ageing score 'SCINEXA' comprising 5 items indicative of intrinsic and 18 items highly characteristic of extrinsic skin ageing. These items were used to define an index (index(discr)) that allowed differentiating between intrinsic versus extrinsic skin ageing. In order to validate the 'SCINEXA', we asked whether it can be used to discriminate regular sunbed users, which have been chronically exposed to ultraviolet radiation and thus are prone to photoageing, from non-sunbed users, which were considered paradigmatic for intrinsic skin ageing.

For this purpose, 58 non-sunbed users and 16 regularly sunbed users were assessed. In addition to the clinical examination of the 23 score items potential confounders were considered by questionnaire.

By employing the index(discr), we were able to classify 92% of all study subjects correctly as sunbed or non-sunbed users. Specifically, an index above 2 was associated with sunbed use and thus extrinsic skin ageing, whereas an index below 2 indicated intrinsic skin ageing.

The novel 'SCINEXA' is suitable for the simultaneous assessment of intrinsic and extrinsic skin ageing.