ABSTRACT
An investigation into the existence of spectral differences and differences in response in terms of water and lipid content between normal and atopic skin is described. Since NIR radiation penetrates complex structured matrices down to a depth of 0.15-0.20 mm, it is evident that the method lends itself to spectral detection of skin components down to the deepest level. First the reproducibility of readings made with the instrument was tested and it was also checked whether the use of the probe caused changes in skin equilibrium due to occlusion. Analysis of the NIR spectra did not enable normal and atopic subjects to be distinguished unequivocally but provided important information on the use of NIR spectrometry in these subjects and insights into the stratum corneum. Although the responses of water and lipid structures could not be read directly from the spectra, it was possible to decompose the global spectral information into components by principal components analysis. It was possible to observe a fraction of variance associated in different ways with water.
Subject(s)
Hypersensitivity/metabolism , Lipid Metabolism , Skin/chemistry , Water/metabolism , Female , Humans , Male , Spectroscopy, Near-InfraredABSTRACT
An investigation into the existence of spectral differences and differences in response in terms of water and lipid content between normal and atopic skin after interaction with chemical agents is described. Three compounds were taken as models: a prevalently hydrophilic solvent (polyethylene glycol, PEG 400), a prevalently lipophilic solvent (isopropyl myristate) and a hydrophilic pharmaceutical (gel) used to promote contact in electrocardiography. Using principal component analysis it was possible to distinguish atopic and normal subjects by simple contact of the skin with chemical agents.
