By using a new standard for the reference skin (albino skin) we could more exactly compare melanin levels in different subjects. Our proposed melanin quantification angle α expresses the extent of the difference in melanin levels between the examined skin lesions. We successfully used this index to quantify the variations of melanin (progress of repigmentation) throughout different stages of treatment of the same lesion and also to objectively evaluate the final effect of the therapy. In the present study, we showed that the diffuse reflectance spectroscopy (DRS) may be suitable method to measure skin colour and the content of human skin melanin in vivo.

Introduction: The clinical method of evaluating the color of the skin based on visual assessment is subjective and thus inaccurate. The objective determination of skin phototypes and levels of melanin in the skin is important for diagnosing the pigment disorders and also for adequate photoprotection. Diffuse refl ectance spectroscopy (DRS) is a non-invasive, precise and objective method for quantifying the melanin levels. Objective: The aim of this study is to assess the characteristic DRS spectrum of healthy skin in children and to detect the differences between them based on age, gender and skin phototype. Material and methods: Skin pigmentation was measured by DRS in 73 children patients with experimental spectrophotometer UM-ES600. The amount of melanin is quantifi ed from the obtained DRS spectra by proposed melanin quantifi cation angle α obtained by comparing the refl ectance properties of skin sample and universal depigmented sample (albino skin). Results: We evaluated spectroscopic characteristics of children's healthy skin depending on age, gender and phototype. The value of melanin quantifi cation angle α grew proportionally from phototype I to phototype IV, without any correlation to age or gender. We confi rmed a clear association between clinical determination of Fitzpatrick's skin phototypes and objective data collected by DRS and related angle α. Conclusions: Our proposed index quantifi es the difference in melanin levels in healthy children skin and also for different skin phototypes. The proposed method and melanin quantifi cation angle α can further be used for the objectifi cation of the progress of pigmentary diseases or for monitoring the effect of their therapy (Tab. 5, Fig. 4, Ref.