Imaging devices for long-wavelength near-infrared light (e.g., MCT, InGaAs) and hyperspectral imaging devices using these wavelengths have recently been developed. This range of wavelengths is especially effective for measuring the composition of objects because it includes the absorption
spectra of molecular vibrations. In this study, long-wavelength near-infrared spectral imaging was used to evaluate allergic dermatitis. Allergic dermatitis can be caused by 2 types of hypersensitivity, immediate (type I) and delayed (type IV), which are activated by different mechanisms.
However, both types of dermatitis are characterized by erythema and localized tissue swelling of the affected area, and it is therefore difficult to determine the type of allergic response by macroscopic inspection. Near-infrared spectral imaging has attracted attention as a non-destructive
inspection method, but while several studies have focused on the detection of edema by near-infrared spectroscopy, the previously reported methods have not attempted to differentiate between different types of allergic dermatitis by detecting intracutaneous targets specific to the different
activation mechanisms. This study aimed to develop a method for the assessment of allergic dermatitis by using the long-wavelength near-infrared spectrum to detect intracutaneous allergic type-specific targets. Such a method was realized by establishing a spectral classifier for the spectra
of type I and type IV allergic dermatitis reactions. A spectral classifier was established from the spectral datasets of histamine-induced cutaneous reaction (immediate type) and contact hypersensitivity erythema elicited by squaric acid dibutylester (SADBE; type IV), and a canonical discriminant
analysis achieved very accurate detection of normal skin and types I and IV allergic dermatitis (normal skin: 87.2%, histamine induced reaction: 71.0%, SADBE contact hypersensitivity: 95.8%). The classifier was next applied to spectral images of 2 other skin conditions, red flare activated
by methyl nicotinate (normal skin) and metal allergy (type IV), and these validation datasets were also correctly classified: the red flare induced by methyl nicotinate was categorized as normal skin and the contact hypersensitivity activated by the metal allergy patch test was categorized
as a type IV allergic reaction. These results suggest a possible application of near-infrared spectral imaging to the assessment of allergic dermatitis.
Document Type: Research Article
Publication date: January 1, 2011
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CIC is the premier annual technical gathering for scientists, technologists, and engineers working in the areas of color science and systems, and their application to color imaging. Participants represent disciplines ranging from psychophysics, optical physics, image processing, color science to graphic arts, systems engineering, and hardware and software development. While a broad mix of professional interests is the hallmark of these conferences, the focus is color. CICs traditionally offer two days of short courses followed by three days of technical sessions that include three keynotes, an evening lecture, and a vibrant interactive papers session. An endearing symbol of the meeting is the Cactus Award, given each year to the author(s) of the best interactive paper presentation.