Assessment of therapeutic response in skin pigment disorder treatment

This paper describes an image analysis technique that objectively measure skin repigmentation for the assessment of therapeutic response in vitiligo treatments. Skin pigment disorders due to the abnormality of melanin production such as vitiligo, cause irregular pale patches of skin. Therapeutic response of treatment results in repigmentation of the skin. However the repigmentation process is very slow and is only observable after a few months of treatment. Currently, there is no objective method in assessing the therapeutic response of skin pigment disorder treatment, particularly for vitiligo treatment. In this work, we apply principal component analysis followed by independent component analysis to represent skin images in terms of melanin and haemoglobin composition respectively. Vitiligo skin areas are identified as skin areas that lack melanin (non-melanin areas). Based on 20 patients, the proposed technique effectively monitored the progression of repigmentation over a shorter time period. The technique can thus be used to objectively evaluate treatment efficacy in a relatively shorter time. Results obtained using the technique have been verified by dermatologists.