title: Quantitative skin color measurements in acanthosis nigricans patients: colorimetry and diffuse reflectance spectroscopy.
abstract: Tristimulus colorimetry and diffuse reflectance spectroscopy (DRS) are white-light skin reflectance techniques used to measure the intensity of skin pigmentation. The tristimulus colorimeter is an instrument that measures a perceived color and the DRS instrument measures biological chromophores of the skin, including oxy- and deoxyhemoglobin, melanin and scattering. Data gathered from these tools can be used to understand morphological changes induced in skin chromophores due to conditions of the skin or their treatments. The purpose of this study was to evaluate the use of these two instruments in color measurements of acanthosis nigricans (AN) lesions. Eight patients with hyperinsulinemia and clinically diagnosable AN were seen monthly. Skin pigmentation was measured at three sites: the inner forearm, the medial aspect of the posterior neck, and anterior neck unaffected by AN. Of the three, measured tristimulus L*a*b* color parameters, the luminosity parameter L* was found to most reliably distinguish lesion from normally pigmented skin. The DRS instrument was able to characterize a lesion on the basis of the calculated melanin concentration, though melanin is a weak indicator of skin change and not a reliable measure to be used independently. Calculated oxyhemoglobin and deoxyhemoglobin concentrations were not found to be reliable indicators of AN. Tristimulus colorimetry may provide reliable methods for respectively quantifying and characterizing the objective color change in AN, while DRS may be useful in characterizing changes in skin melanin content associated with this skin condition.
authors.affiliation: Department of Dermatology, Henry Ford Hospital, Detroit, MI 48202, USA.
authors.forename: Bensachee
authors.initials: B
authors.lastname: Pattamadilok
authors.forename: Suneetha
authors.initials: S
authors.lastname: Devpura
authors.forename: Zain U
authors.initials: ZU
authors.lastname: Syed
authors.forename: Oma N
authors.initials: ON
authors.lastname: Agbai
authors.forename: Pranita
authors.initials: P
authors.lastname: Vemulapalli
authors.forename: Marsha
authors.initials: M
authors.lastname: Henderson
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Rehse
authors.forename: Bassel H
authors.initials: BH
authors.lastname: Mahmoud
authors.forename: Henry W
authors.initials: HW
authors.lastname: Lim
authors.forename: Ratna
authors.initials: R
authors.lastname: Naik
authors.forename: Iltefat H
authors.initials: IH
authors.lastname: Hamzavi
mesh_terms: D000052:Acanthosis Nigricans / Q000378:metabolism / Q000473:pathology; D000293:Adolescent; D002648:Child; D003124:Colorimetry; D005260:Female; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008543:Melanins / Q000378:metabolism*; D010108:Oxyhemoglobins / Q000378:metabolism*; D012867:Skin / Q000378:metabolism / Q000473:pathology; D012880:Skin Pigmentation; D013057:Spectrum Analysis
chemical_list: D006454:Hemoglobins; D008543:Melanins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin