Optoacoustic mesoscopy shows potential to increase accuracy of allergy patch testing. (19th May 2020)

• Record Type: Journal Article
• Authors: Hindelang, Benedikt; Aguirre, Juan; Berezhnoi, Andrei; He, Hailong; Eyerich, Kilian; Ntziachristos, Vasilis; Biedermann, Tilo; Darsow, Ulf
• Is Part Of: Contact dermatitis. Volume 83:Number 3(2020)
• Page Start: 206
• Page End: 214
• Publication Date: 2020-05-19
• Subjects: allergy -- contact dermatitis -- optoacoustic imaging -- patch test -- photoacoustic imaging; Contact dermatitis -- Periodicals; 616.51
• DOI: 10.1111/cod.13563
• Languages: English
• ISSNs: 0105-1873

Abstract

Abstract: Background: Differentiation between irritant and allergic skin reactions in epicutaneous patch testing is based largely on subjective clinical criteria, with the risk of high intraobserver and interobserver variability. Novel dermatological imaging using optoacoustic mesoscopy allows quantitative three‐dimensional assessment of microvascular biomarkers. Objectives: We investigated the potential of optoacoustic imaging to improve the precision of patch test evaluation. Methods: Sixty‐nine test reactions and 48 healthy skin sections in 52 patients with suspected type IV allergy were examined using raster‐scan optoacoustic mesoscopy. Results: We identified biomarkers from the optoacoustic images. Allergic reactions were associated with higher fragmentation of skin vasculature than irritant reactions (19.5 ± 9.7 vs 14.3 ± 3.7 fragments/100 pixels 2 ; P < .05), as well as lower ratio of low‐ to high‐frequency acoustic signals (1.6 ± 0.5 vs 2.0 ± 0.6, P < .05). Allergic reactions graded "++" showed higher vessel fragmentation than reactions graded "+" (25.4 ± 13.2 vs 17.1 ± 6.5 fragments/100 pixels 2 ; P < .05). A linear model combining the biomarkers fragmentation and frequency ratio could differentiate allergic from irritant test reactions with an area under the receiving operator characteristic curve of 0.80 (95% confidence interval 0.64‐0.91), reaching a sensitivity of 81% and specificity of 63%. Conclusions: Optoacoustic mesoscopy shows potential to help in differentiating between allergic and irritant test reactions based on novel biomarkers that may reflect vasodilation, vessel tortuosity, and edema. Abstract : Optoacoustic mesoscopy can be used for high‐resolution imaging of skin reactions in epicutaneous patch testing. Compared with irritant reactions, allergic reactions show significantly more high‐frequency optoacoustic signal and a more fragmented vessel signal. Used as a complementary diagnostic tool, raster‐scan optoacoustic mesoscopy holds potential to improve the precision of allergy patch testing.